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Microplastics are increasingly entering marine, limnic and terrestrial ecosystems worldwide, where they sorb hydrophobic organic contaminants. Here, the sorption behavior of the fuel-related water contaminants benzene, toluene, ethyl benzene and xylene (BTEX) and four tertiary butyl ethers to virgin and via UV radiation aged polypropylene (PP) and polystyrene (PS) pellets was investigated. Changes in material properties due to aging were recorded using appropriate polymer characterization methods, such as differential scanning calorimetry, Fourier transform infrared spectroscopy, gel permeation chromatography, X-ray photoelectron spectroscopy, and microscopy.
Pellets were exposed to water containing BTEX and the ethers at 130-190 mg/L for up to two weeks.
Aqueous sorbate concentrations were determined by headspace gas chromatography. Sorption to the polymers was correlated with the sorbate's Kow and was significant for BTEX and marginal for the ethers.
Due to substantially lower glass transition temperatures, PP showed higher sorption than PS. Aging had no effect on the sorption behavior of PP. PS sorbed less BTEX after aging due to an oxidized surface layer.
Leachiing tests - a useful tool for the environmental impact assessment of construction products?
(2018)
Construction products and waste materials used for construction can be in contact with the environment and may release potential harmful compounds. Information on the total content of these substances in the product is not sufficient to assess its envrionmental impact since it does not consider realistic exposure conditions.The impact of these compounds is often assessed by using the total content in the product. This estimation lacks realistic exposure conditions.
Concerning the pathway to soil and groundwater by contact with rain or seepage water leaching tests, which were developed and standardized by the European Committee for Standardization, are available. While for secondary construction products and waste this investigation of the leaching behaviour is standard procedure and is already part of regulation in Germany (draft ordinance on reuse of mineral waste) and within Europe (landfill directive) the release from primary construction products got in the focus more recently. Several monitoring studies found unexpected high concentrations of substances used as herbicides and fungicides in surface water and stormwater originating from urban areas. As some of these compounds are even banned for the use in agricultural applications in Europe alternative sources as roof materials and façade coatings exposed to rain were suggested. Further field and laboratory tests confirmed construction products as sources of these substances in water.
The aim of this presentation is to show exemplary results of existing leaching methods and underline the strength and weaknesses of the test system with selected examples from our work. We especially draw the attention to the research which is still needed to close the gap between the results of leaching experiments and the subsequent risk assessment of the products.
The production of secondary materials from waste materials requires, in most cases, significantly lower energy amounts than the primary material production of raw materials. Along with lower energy demand, the greenhouse gas emissions produced are also lower. The duty of a modern waste management system should therefore be to collect and sort the waste materials in a way that the highest amounts of single material fractions with the highest qualities can be generated. In this contribution, the greenhouse gas balances of the theoretical treatment of the household waste, if collected as mixed waste in sanitary landfills, in waste incineration plants, or in mechanical-biological treatment plants, are compared to the existing separate waste collection and treatment in Germany in 2014. The results show that the treatment of the mixed collected household waste in sanitary landfills would lead to a significant release of greenhouse gases. The treatment in MBTs with the recovery of valuables and the further disposal of the biologically stabilized fraction on landfills, as well as the treatment of the high calorific fraction (also called refuse derived fuel – RDF) in RDF plants, coal-fired power plants, or cement kilns, would lead to small amounts of avoided greenhouse gas emissions. The thermal treatment in waste incineration plants would lead to moderate amounts of avoided greenhouse gases. Only with the actually practiced separate collection and treatment of household waste were significant amounts of greenhouse gas emissions avoided. In total, this is approximately 5.5 million tons of carbon dioxide equivalents for approximately 45.5 million tons of separate collected and treated household waste in Germany in 2014.
The production of secondary materials from waste materials requires, in most cases, significantly lower energy amounts than the primary material production of raw materials. Along with lower energy demand, the greenhouse gas emissions produced are also lower. The duty of a modern waste management system should therefore be to collect and sort the waste materials in a way that the highest amounts of single material fractions with the highest qualities can be generated. In this contribution, the greenhouse gas balances of the theoretical treatment of the household waste, if collected as mixed waste in sanitary landfills, in waste incineration plants, or in mechanical-biological treatment plants, are compared to the existing separate waste collection and treatment in Germany in 2014.
Direct and indirect effects (DIERec) of the recovery of secondary resources are in the range of 500 million tonnes per year in Germany; energy savings are 1.4 million TJ. These savings are between 10 and 20% of the total. The effects of materials recovery exceed those of energy recovery by far with the exception of secondary plastic material where DIERec from energy recovery is higher by factor of 2.7. Untapped potential for the recovery of secondary resources exist in the fine fraction of bottom ash from municipal solid waste incineration, mainly Cu and precious metals and in urban mining.
Wood treated with nano metal fluorides is found to resist fungal decay. Sol−gel synthesis was used to synthesize MgF2 and CaF2 nanoparticles. Electron microscopy images confirmed the localization of MgF2 and CaF2 nanoparticles in wood. Efficacy of nano metal fluoride-treated wood was tested against brown-rot fungi Coniophora puteana and Rhodonia placenta. Untreated wood specimens had higher
mass losses (∼30%) compared to treated specimens, which had average mass loss of 2% against C. puteana and 14% against R. placenta, respectively. Nano metal fluorides provide a viable alternative to current wood preservatives.
Tools for the characterization of secondary raw materials - status of leaching test application
(2018)
Leaching tests are used as tools for the assessment of environmental compatibility of granular waste materials with potential for reuse. The presentation gives an overview on available leaching tests, their field of application and relation to legislation. Furthermore robustness testing to elaborate optimized test conditions as well as performance characteristics from validation studies by BAM are addressed.
Tools for the characterization of secondary raw materials - status of leaching test application
(2018)
Leaching tests are used as tools for the assessment of environmental compatibility of granular waste materials with potential for reuse. The presentation gives an overview on available leaching tests, their field of application and relation to legislation. Furthermore robustness testing to elaborate optimized test conditions as well as performance characteristics from validation studies by BAM are addressed.
Construction products are in contact with water (e.g., rain, seepage water) during their service lifetime and may release potentially harmful compounds by leaching processes. Monitoring studies showed that compounds attributed to construction products are found in storm water and the receiving bodies of water and that the release of biocides in urban areas can be comparable to the input of pesticides from agricultural uses. Therefore, a prospective risk assessment of such products is necessary. Laboratory leaching tests have been developed by the Technical Committee CEN/TC 351 and are ready to use. One major task in the future will be the evaluation of the leaching test results, as concentrations found in laboratory experiments are not directly comparable to the field situations. Another Task will be the selection of compounds to be considered for construction products, which are often a complex mixture and contain additives, pigments, stabilization agents, etc. The formulations of the products may serve as a starting point, but total content is a poor predictor for leachability, and analysis of the eluates is necessary. In some cases, nontargeted approaches might be required to identify compounds in the eluates. In the identification process, plausibility checks referring to available information should be included. Ecotoxicological tests are a complementary method to test eluates, and the combined effects of all compounds—including Degradation products—are included. A bio test battery has been applied in a round robin test and was published in a guidance document. Published studies on the ecotoxicity of construction products show the tests’ suitability to distinguish between products with small and larger effects on the environment.
The presentation gives an overview about the use of ecotoxicity testing in assessment of waste. Especially in cases with unknown composition this kind of test are useful. Recently, the assessment of the hazard property HP 14 "ecotoxicity" for the labelling of waste was published. The labelling procedure is explained in detail.
The presentation gives an overview about the use of ecotoxicity testing in assessment of waste. Especially in cases with unknown composition this kind of test are useful. Recently, the assessment of the hazard property HP 14 "ecotoxicity" for the labelling of waste was published. The labelling procedure is explained in detail.
The presentation gives an overview about the use of ecotoxicity testing in assessment of waste. Especially in cases with unknown composition this kind of test are useful. Recently, the assessment of the hazard property HP 14 "ecotoxicity" for the labelling of waste was published. The labelling procedure is explained in detail.
Potential use of incineration bottom ash in construction – Evaluation of environmental impact
(2018)
Around 5 million tonnes of MSWI bottom ash (BA) are generated per year in Germany. The incineration itself serves for metals as a concentrating and cleaning process. However, due to the almost exclusive wet extraction out of the furnace chamber the various metals are integrated in a heterogeneous and instable matrix. The metal recovery is therefore still a challenge relating the recovery rate and the purity, respectively. With state of the art treatment trains in Germany around 7.7% of ferrous metals and 1.3% of non-ferrous metals can be recovered out of MSWI BA. Large quantities of the mineral fraction are reused for sub-base material in road construction. A three month ageing period has been established as the common practice of further treatment of bottom ash before reuse applications. In the course of this aging the pH value of bottom ash decreases and contaminants are immobilized by processes like carbonation, hydration and oxidation. In particular leaching of heavy metals may be reduced to environmentally acceptable levels. However, the aging results in fixing of other valuable resources such as metals. Two laboratory scale lysimeters (30 cm in diameter) are being operated for more than three years aiming at the investigation of the long-term leaching behavior of a 0.25/45 mm mineral material obtained by treatment of MSWI bottom ash directly after incineration by a wet processing technology. Artificial rainwater is used as leachant (pH ≈ 6, ingredients NO32-, Cl-, SO42-, Na+, K+, Ca2+, Mg2+). The lysimeters are irrigated related to an average annual precipitation rate of 600 mm/a leading to a liquid to solid ratio (L/S) of about 0.7 per year of operation. Lysimeter tests are more adequate to simulate field scenarios and long-term leaching behavior in contrast to laboratory column tests particularly due to the unsaturated conditions and realistic contact time with the leachant.
In comparison to the leaching of bottom ash (aged for 3 month and non-treated) in column tests the chloride and sulfate leaching in the lysimeters was reduced as a consequence of the previous wet processing. The sulfate release kept almost constant limited by CaSO4 solubility up to an L/S of about 0.7 l/kg. The chloride concentrations dropped quickly, starting from 7300 mg/l, and are now at an almost constant level of 50 mg/l which is significantly above the chloride concentration in the leachant. After an initial decrease of the pH from about 10.4 to 8 at L/S of 0.2 l/kg, the pH increased again and leveled out around 9.8 up to L/S 2.2 l/kg. At an L/S of about 2.5 l/kg now, Cr, Cu are still released. The Cu and Cr concentrations in the leachates were about 760 µg/l and 90 µg/l respectively at the beginning. For both metals the concentration decreased to about 35 µg/l now. The Mo concentrations dropped steadily from 1300 to 250 µg/l, whereas V and Sb concentrations increased in the course of the tests. Fe and Mn are not detectable anymore. More results of this experimental study will be presented and discussed with a special focus on elements forming oxyanions.
Whereas the behavior of geosynthetics in landfill engineering is well studied and documented since decades, little is known on application in applications such as coastal protection or ballast layers for wind energy plants.
However, due to the rapid expansion of offshore wind energy, rising water levels and more extreme weather conditions as a result of climate change more and more hydraulic engineering projects will be realized in the future.
Construction with geosynthetics has various advantages, but it has to be ensured that there is no negative environmental impact from the application of geosynthetics in hydraulic engineering.
It is expected that any effect will be visible only on the long-term. Therefore, accelerated testing is needed to derive requirements for geosynthetics in hydraulic engineering.
Small grain size fractions of municipal solid waste incineration (MSWI) bottom ash (BA) contain elemental and chemically bonded metals in appreciable amounts, especially copper. Investigations with a centrifugal concentrator were carried out using samples, which had been treated with different impact devices. Partly the impacts of single devices were visible in outlines, but mostly the surfaces of the metals were still covered with mineral residues. To generate copper rich fractions, parameters of the separation process should ensure mass yields <2%, best between 0.5 and 1%. The density of the concentrates is then generally >3.2 g/cm3. Best results were achieved with material from a special treatment train which is adapted to grain sizes <2 mm. Reliable copper contents between 20 and 40% (single runs >50%) could be realised.
However, considering the required mass yields, referred to this subset only 150–170 g copper would be recovered from 1 Mg MSWI BA. Furthermore, this copper is only in parts present in elemental form. A
dependable added value of such treatment step seems to be given only, if that enables a recycling of the mineral aggregates (tailings) in parallel to avoid landfill costs.
Waste-to-energy (WtE) is one of the leading technologies for municipal solid waste (MSW) treatment in Europe. According to Eurostat data, in 2015, 27 % of MSW was utilized in WtE plants, which represents more than 80 million tons per year. Therefore, the European annual production of incineration bottom ash (IBA) is about 20 million tons, as it is about 25 wt% of input MSW. In the European List of Waste, IBA is listed as mirror entry (i.e. waste materials which should be classified as either non-hazardous or hazardous, depending on its hazardous properties and/or content of hazardous substances) under codes 19 01 11 and 19 01 12.
Recent trends indicate that WtE allows, apart from utilization of the energy content of waste, also the recovery of various valuable components. Hence, WtE can be included in the key technologies that can put the circular economy concept into practice. Secondary raw materials in the case of WtE are solid residues, especially IBA, as it is a secondary source, particularly of ferrous metals (Fe) and non-ferrous metals (NF) and glass. Moreover, the residual mineral fraction can be used for various applications in the construction industry, i.e. as aggregates substitute for bound or unbound applications, in cement manufacturing or, as indicated by recent research, also in more sophisticated applications, e.g. for ceramics production. Recovery of these metals can also cause huge greenhouse gas savings. Alone in Europe, metal recovery from IBA reduces greenhouse gas emissions by approximately 3.2 million tonnes of CO2 equivalent.
Direct and indirect effects (DIERec) of the recovery of secondary resources are in the range of 500 million tons per year in Germany; energy savings are 1.4 million TJ. These savings are between 10 and 20% of the total. The effects of materials recovery exceed those of energy recovery by far except for secondary plastic material, where DIERec from energy recovery is higher by factor of 2.7. Untapped potential for the recovery of secondary resources exists in the fine fraction of bottom ash from municipal solid waste incineration, mainly Cu and precious metals, and in urban mining.
Geosynthetics are widely used in hydraulic engineering and within coastal protection constructions at the Baltic Sea shore, such as walls, promenades, and gabions walls. Storms influence leads to deformation of some of the protection structures and cause the release of geotextiles onto the beach. Fragments of geotextile migrate along the shore, experiencing additional degradation and destruction down to macro-, meso-, and micro-particles. During October 2017 - March 2018, the Baltic Sea shore along the Sambia Peninsula (Kaliningrad Oblast of the Russian Federation) was monitored to establish the contamination of sandy beaches by geotextiles that had degraded. Several local sources of pollution of beaches by geosynthetic materials were established.
Die Präsentation erläutert die Hintergründe der nationalen Anforderungen für die Verwendung von Kunststoffdichtungbahnen in Deponieabdichtungen. Die Beständigkeit wird diskutiert. Anforderungen an das Qualitatsmanagement während der Produktion der Produkte und der Bauphase werden aufgezeigt und die Auswirkungen auf die langzeitige Funktionserfüllung werden beschrieben.
Transformation of carbendazim, diuron, octylisothiazolinone and terbutryn was investigated in two paints containing either white titanium dioxide or a red iron oxide pigment.
Test specimens of these coatings on glass were exposed to water contact and UVA-radiation under laboratory conditions. Panels of birch plywood were coated and exposed to natural weather conditions in a field experiment. Concentrations of biocides and transformation products were analysed in leachates from laboratory tests, runoff samples and remaining coatings. Water contact, UVA radiation as well as pigments in the paints affected the pattern and amount of transformation products.
In Denmark, increasing amounts of woody biomass are being used for the production of renewable energy, resulting in more wood ashes being generated. While these materials have been mainly landfilled, wood ashes may also be utilised for fertilizing and liming purposes on top of soils. Pre-treatments involving hardening or granulation may be carried out prior to soil application. In this study, two Danish wood ash samples were hardened and/or granulated. Lab-hardening induced rapid changes in the shape of the acid neutralisation capacity curve of the ashes. Up-flow column tests, assuming local equilibrium conditions, were employed to investigate the leaching from pre-treated ashes. Granules and loose ashes demonstrated similar leaching behaviours, indicating that similar geochemical processes were governing their leaching. In comparison with untreated fresh ashes, the hardened ashes demonstrated reduced leaching of Ca, Ba, Pb and Zn with concentration levels generally below or close to the analytical limits of quantification; to the contrary, the leaching of As, P, Sb, Si, V and Mg was enhanced in the hardened ashes. The release of alkalinity was reduced by hardening. In general, all granules were barely breakable by finger-pinching and they could withstand one month of continuous leaching, preserving their overall shape. The solubility of phosphorous in neutral ammonium citrate indicated that about 30–51% of the total P content in the ash samples was released, suggesting that the ashes could be potentially valuable as P-fertiliser if applied onto soil.
The environmental compatibility of reactive fire-retardant coatings (intumescent paints) was investigated by a combination of leaching and ecotoxicological tests. Three representative fire-retardant coating systems were tested using two leaching procedures: “Horizontal Dynamic Surface Leaching Test” (DSLT) and the “Intermittent Immersion Test” (IIT). All eluate fractions (8 for DSLT and 9 for IIT) were analyzed for pH, conductivity, concentration of total organic carbon and selected anions und cations. Additionally, a GC-MS screening of selected fractions was conducted for identification of organic compounds. Eluate fractions 1 + 2 and fraction 7 of the DSLT were analyzed in four ecotoxicological tests (algae, daphnia, fish egg, luminescent bacteria) and in one genotoxicity test (umu). Concentration of most analytes was rather low or below limit of detection for many eluates. Analytes detected in eluates of all three products are Zn, Ba, SO4(2−) and PO4(3−). Release patterns do not indicate a general trend: some compounds show maximum release in the first fractions while for others the maximum was observed in later test stages. Ecotoxic effects in eluates were found, which were higher in the eluate fraction 7 (maximum lowest ineffective dilution for luminescent bacteria (LIDL) 256) than in the eluate fraction 1 + 2 (maximum LIDL = 24). The sensitivity of the test systems was very different with highest effects for luminescent bacteria, followed by algae and daphnia and without effects in the fish egg test and umu test. A biotest battery for the comprehensive assessment is therefore advisable.
Leaching processes are responsible for the release of biocides from treated materials into the environment.
Adequate modeling of emission processes is required in order to predict emission values in the framework of the risk assessment of biocidal products intended for long-term service life. Regression approaches have been applied to data obtained from the long-term monitoring of biocide emissions in experiments involving semi-field conditions. Due to the complex interaction of different underlying mechanisms such as water and biocide diffusion and desorption, however, these attempts have proven to be of limited usefulness e at least, for the available biocide emission data. It seems that the behavior of the biocide emission curve depends to a considerable extent on whichever underlying mechanism is slowest at a given point in time, thus limiting the amount of biocide available for release. Building on results obtained in the past few years, the authors propose a criterion for determining which mechanism controls the leaching process at a given point in time based on the slope of the log-log emission curve. In addition, a first-order approximation of this slope value is presented which displays advantages both in terms of computability and interpretability. Finally, an algorithm for the determination of breakpoints in the slope of the log-log emission curve is presented for the demarcation of phases within which one mechanism acts as a limiting factor.
Draft standards for the determination of organic pollutants in the solid matter of environmental matrices such as sludge, treated biowaste and soil have been basically developed in the framework of the European standardization project HORIZONTAL. A research project financed by the German Federal Environment Agency was initiated to finalize some of these CEN standard drafts, since fully validated standard procedures are crucial for the evaluation of their reliability in the context of implementation in legislation on environmental health.
Approach: Appropriate test materials (< 2mm particle size) were prepared and homogenized from contaminated soils, sludge and treated biowaste containing polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), dioxins, furans and dioxin-like-PCB and served, along with reference solutions, as the basis for international interlaboratory comparisons. Performance data of three analytical standard procedures were obtained by the statistical evaluation of results received from 11 to 29 participants per test material.
Results: The overall variation coefficients of reproducibility (between-lab standard deviations) for the sum parameters were roughly between 10 and 35 %. The variation coefficients of repeatability (within-lab standard deviations) range between 3 % and 8 % and show no trend considering the substance groups or matrices.
The highest coefficients of reproducibility were found for the analysis of PAHs, which were between 26 and 35 %, depending on the matrix, whereas 7-17 % reproducibility was observed for toxicity equivalents (TEQ) comprising dioxins, furans and dl-PCB.
Conclusions: Overall, the results confirm that the procedures described in the Technical Specifications are fit for purpose for all three matrices and that the feasibility of the HORIZONTAL approach, to cover several matrices with one standard per analyte, was thereby proven.
An approach to achieve 'zero leakage' is discussed with respect to experience in Germany, where strict regulations for landfill lining and capping Systems have been developed and issued because of large environmental Problems related to landfills that accumulated in the 1970s and 1980s. Using a thick, high-quality high-density Polyethylene (HDPE) geomembrane (GM) that is installed free of residual waves and wrinkles in intimate contact with a compacted clay liner or geosynthetic clay liner of very low permeability, by a qualified, experienced, well-equipped and properly third-party-controlled installer, and which is protected by heavy protection layers designed with respect to the long-term performance of the GM may result in a liner or capping system of practically no leakage. This is demonstrated by analysing results of measurements obtained from permanently installed leak-detection Systems in combination with HDPE GMs. The survey was based on 32 German landfills with 1.276.500 m² of installed GMs.
Paragraphs 6 to 8 of the proposed amendment to the German Federal Soil Protection and Contaminated Sites Ordinance contain new requirements regarding the application of soil-like material outside of a rootable soil layer. For example, it is intended to enable reusing of soil-like materials containing regulated substances in concentrations between the single and double precautionary values (PV), provided that the limit values for the eluate are complied with. The aim of a running project (funding code UFOPLAN 3716 74 203 0, German Federal Environmental Agency) is to fill data deficits for soil-like materials which meet the above-mentioned criteria to promote circular economy and conservation of natural resources. Different soil-like materials of various origin (for example dredged material, banquet peeling material, urban and meadow soils) are considered with a special focus on PAHs. A major challenge in sample acquisition is the relatively narrow target range of the PAH content between 3 and 6 mg/kg dm considering a high measurement uncertainty at this concentration level.
The contents of PAHs, heavy metals and other inorganic elements in solid matter are determined following established standards. In addition, the soil-like materials are characterized concerning particle size, pH, conductivity, SOM, TOC and carbonate content. To determine the eluate concentration, column tests according to DIN 19528 and batch tests according to DIN 19529 at a liquid/solid ratio (L/S) of 2 l/kg and 10 l/kg are performed comparatively.
The results show that the new requirements of the planned amendment to the Federal Soil Protection and Contaminated Sites Ordinance certainly opens additional possibilities for reuse of soil-like materials. Even most soil-like materials within 2-3 x PV comply with the eluate value for PAH (0.2 μg/l) both in the batch test and in the column test at L/S 2 l/kg. Selected inorganic substances lead to similar evaluations. Therefore, the application of such soil-like materials outside of rootable soil layers would be possible. Previously, those materials were often used for landfill construction. In the future, a utilization in the adjacent environment by backfilling, recultivation, renaturation, composting or landscaping would be conceivable.
Column leaching tests are frequently used and accepted for investigation of release of hazardous substances from solid materials. Independent of differences due to the field of application or national regulations, column tests assume that local equilibrium is established in the experiment which facilitates transfer of results to field conditions. In the process of harmonization and standardization within Europe the question on the influence of flow rate and grain size distribution on the local equilibrium was raised. Thus, a set of experiments using two different masonry materials with varying grain size distribution and flow rate were conducted including stop/flow experiments. Results are compared to a numerical model which takes intraparticle pore diffusion-controlled release of Mo and V into the percolating water into account. Due to the relatively high intraparticle porosity of the materials (24–29%) data and model indicate that initially equilibrium-state conditions prevail followed by rapidly decreasing concentrations. The model fits data for Mo and V reasonably well; however, after the initial decline of concentrations (at L/S > 2) extended tailing is observed especially of elements occurring as oxides, which is not captured by the model.
Since it was realized that sites contaminated with metals and radionuclides needed treatment, various remediation methods have been and are being developed. Depending on the size of the contaminated site and urgency of intervention, conventional or recently introduced techniques have been used. Conventional techniques include excavation and removal for treatment of soil and contaminants, or the so-called “pump-and-treat” method, in which contaminated groundwater is removed from the ground by pumping and treated in a treatment plant on the surface. It has the advantage of using proven techniques and is easy to control, and the treated groundwater can be reinjected into the ground or discharged in rivers or lakes. Novel methods include permeable reactive barriers, biomineralization, and electrokinetic remediation.
Biocides are commonly applied to construction materials such as facade renders and paints in order to protect them from microbial spoilage. These renders and paints are exposed to weathering conditions, e.g., sunlight and rain. Pigments are interacting intensively with the spectrum of the incoming light; thus, an effect of paint pigments on phototransformation rates and reaction pathways of the biocides is hypothesized.
In this study, the phototransformation of four commonly used biocides (carbendazim, diuron, octylisothiazolinone (OIT) and terbutryn) in four different paint formulations differing solely in pigments (red and black iron oxides, white titanium dioxide, and one pigment-free formulation) were investigated. Paints surfaces were irradiated under controlled conditions. The results show that biocides degrade most rapidly in the pigment-free formulation. The degradation in the pigment-free formulation followed a first-order kinetic model with the respective photolysis rate constants: kp,Diuron=0.0090 h−1, kp,OIT=0.1205 h−1, kp,Terbutryn=0.0079 h−1.
Carbendazim concentrations did not change significantly. The degradation was considerably lower in the pigment-containing paints. The determination of several phototransformation products of terbutryn and octylisothiazolinone showed different transformation product ratios dependent on the pigment. Consequently, pigments not only reflect the incoming light, but also interact with the biocide photodegradation.
Waste, Evaluation Methods
(2019)
It is difficult to decide which waste management system fulfills best predefined sustainability goals such as maximum materials and energy recovery, least environmental impact, and lowest societal cost. Such decisions are based on many parameters. However, several evaluation methods exist with different scope and output, and the application of one or more evaluation methods provides an objective comparison of alternatives.
Designing the performance of geogrids in reinforce soil constructions usually does not consider long-term behavior and possible failure modes of junctions between longitudinal and transverse ribs. How could behavior of junctions be included? To which extend is it necessary? On the conference Geo-Chicago 2016, Swan and Yuan presented an ultimate limit state equation for the short-term material resistance of junctions. We discuss limitations and suggest improvements to include long-term behavior of junctions. Nevertheless, the approach applies only to a specific mode of shear-tensile failure of junctions and only to strictly rigid geogrids. A new design concept presented in the same year by Jacobs on the conference GeoAmerica for the special case of the anchorage of geogrids, which reinforce capping system on long and steep slopes of landfills, tried to overcome these drawbacks. We discuss the aspects of this concept related to the long-term behavior of junctions and the interplay between the load applied to junctions and the flexibility of longitudinal ribs. This interplay and the long-term junction strength determine the long-term behavior of geogrids.
The Brazilian sugarcane industry produced around 173 million tons (Mt) of bagasse in 2018. Bagasse is a by-product of juice extraction for ethanol and sugar production and is combusted in order to generate power, producing up to 10 Mt of ash per year. This ash contains various concentrations of plant nutrients, which allow the ash to be used as a crop fertilizer. However, the concentration and extractability of phosphorus (P), an essential plant nutrient, are low in bagasse ash. To increase the P content, we co-gasified and co-combusted bagasse with P-rich chicken manure. The resulting ash was thermochemically post-treated with alkali additives (Na2SO4 and K2SO4) to increase the availability of P to plants. We aimed to: (i) investigate the effect of thermochemical post-treatment of co-gasification residue and co-combustion ash on P availability to soybeans, (ii) explore the potential of chemical extraction methods (citric acid, neutral ammonium citrate, formic acid, and Mehlich-I) and diffusive gradients in thin films (DGT) to predict the availability of P to soybeans, and (iii) identify the responsible P-phases using X-ray diffraction . We evaluated P availability to soybeans growing in Brazilian Oxisol soil in two independent greenhouse pot experiments. The positive effect of thermochemical treatment on P availability from gasification residue was confirmed through the observation of increased P uptake and biomass in soybean plants. These findings were confirmed by chemical extraction methods and DGT. The gasification residue contained whitlockite as its main P-bearing phase. Thermochemical post-treatment converted whitlockite into highly soluble CaNaPO4. In contrast, co-combustion ash already contained highly soluble Ca(Na,K)PO4 as its main P-bearing phase, making thermochemical post-treatment unnecessary for increasing P availability. In conclusion, increased extractability and availability of P for soybeans were closely connected to the formation of calcium alkali phosphate. Our findings indicate that this combined methodology allows for the prediction of P-fertilization effects of ash.
The potential release of hazardous substances from polymer-based products is currently in the focus of environmental policy. Environmental simulations are applied to expose such products to selected aging conditions and to investigate release processes. Commonly applied aging exposure types such as solar and UV radiation in combination with water contact, corrosive gases, and soil contact as well as expected general effects on polymers and additional ingredients of polymer-based products are described. The release of substances is based on mass-transfer processes to the material surfaces. Experimental approaches to investigate transport processes that are caused by water contact are presented. For tailoring the tests, relevant aging exposure types and release quantification methods must be combined appropriately. Several studies on the release of hazardous substances such as metals, polyaromatic hydrocarbons, flame retardants, antioxidants, and carbon nanotubes from polymers are summarized exemplarily. Differences between natural and artificial exposure tests are discussed and demonstrated for the release of flame retardants from several polymers and for biocides from paints. Requirements and limitations to apply results from short-term artificial environmental exposure tests to predict long-term environmental behavior of polymers are presented.
Phosphorus (P) fertilizers from secondary resources became increasingly important in the last years. However, these novel P-fertilizers can also contain toxic pollutants such as chromium in its hexavalent state (Cr(VI)). This hazardous form of chromium is therefore regulated with low limit values for agricultural products even though the correct determination of Cr(VI) in these fertilizers may be hampered by redox processes, leading to false results. Thus, we applied the novel diffusive gradients in thin-films (DGT) technique for Cr(VI) in fertilizers and compared the results with the standard wet chemical extraction method (German norm DIN EN 15192) and Cr K-edge X-ray Absorption near-edge structure (XANES) spectroscopy. We determined an overall good correlation between the wet chemical extraction and the DGT method. DGT was very sensitive and for most tested materials selective for the analysis of Cr(VI) in P-fertilizers. However, hardly soluble Cr(VI) compounds cannot be detected with the DGT method since only mobile Cr(VI) is analyzed. Furthermore, Cr K-edge XANES spectroscopy showed that the DGT binding layer also adsorbs small amounts of mobile Cr(III) so that Cr(VI) values are overestimated. Since certain types of the P fertilizers contain mobile Cr(III) or partly immobile Cr(VI), it is necessary to optimize the DGT binding layers to avoid aforementioned over- or underestimation. Furthermore, our investigations showed that the Cr K-edge XANES spectroscopy technique is unsuitable to determine small amounts of Cr(VI) in fertilizers (below approx. 1% of Cr(VI) in relation to total Cr).
Many organizations in Europe collect data and perform research on municipal solid waste and the secondary raw materials that can be produced from them through recycling, urban mining, or landfill mining.However, the information generated and presented thereby is often highly aggregated, while research activities are many a time isolated. Both reduce the usability of the data and information generated. In order to better structure the knowledge generation on secondary raw materials production from municipal solid waste, we suggest to learn from the traditional raw materials mining Industry how to perform an integrated assessment and reporting of anthropogenic resources. This is exemplarily shown for the case of the anthropogenic resource municipal solid waste incineration bottom ash and airpollution control residues. A network of expert institutions from countries throughout Europe was build up to compile the information on legal and technological aspects for the recovery of different secondary raw materials from these residues, including construction minerals, metals, and salts. We highlight in our article the strength of the combined knowledge of an expert network not only on legal and technological, but also local and site-specific aspects of the recovery of secondary raw materials. By doing so, we hope to kick-off a discussion for how to organize and implement a structure for a better management of knowledge on anthropogenic resources, in order to provide a sustainable supply of secondary raw materials for a greener and more circular economy.
EI‐GEO is a multinational research project (Germany, Latvia, Russia) funded under the ERA.Net RUS Plus Call 2017. Aim of the project is the investigation whether geosynthetics in hydraulic engineering applications could be a source of microplastics (MPs) and other contaminants to the aquatic environment causing negative effects to aquatic organisms.
Whereas the behavior of geosynthetics in landfill engineering is well studied and documented since decades, little is known on application in applications such as coastal protection or ballast layers for wind energy plants. However, due to the rapid expansion of offshore wind energy, rising water levels and more extreme weather conditions as a result of climate change more and more hydraulic engineering projects will be realized in the future.
Applied methods are artificial ageing of geosynthetics in environmental simulation chambers, storage of samples under environmental condition for comparison with laboratory simulation, sample characterization by microscopic methods and ecotoxicological testing of water in contact with geosynthetics.
In parallel a case study at the Baltic Sea shore at Kaliningrad Oblast (Russia) will be performed. The aim of study is to estimate the level of pollution of the beaches by geosynthetic debris and identify the possible sources.
Potential use of incineration bottom ash in construction – Evaluation of the environmental impact
(2020)
Knowledge of the long-term leaching behavior of potentially harmful substances is crucial for the assessment of the environmental compatibility of reusing municipal solid-waste incineration bottom ash (MSWI BA) in construction, i.e., as a road base layer.
BA fractions obtained from wet-processing aiming at the improvement of environmental quality were used to investigate the mobility of relevant substances. Eluates from laboratory-scaled leaching procedures (column percolation and lysimeters) were analyzed to learn about the long-term release of substances. Unsaturated conditions and artificial rainwater (AR) were used in the lysimeter tests to simulate field conditions. In addition, batch test eluates were generated at usual liquid-to-solid ratios (L/S) for compliance testing purposes. A variety of cations and anions was measured in the eluates.
The wet treatment reduces the leaching of chloride and particularly sulfate by more than 60%. The release of typical contaminants for the treated MSWI BA such as the heavy metals Cu and Cr was well below 1% in the conducted leaching tests.
An increase in the Sb concentration observed in the lysimeter experiments starting at L/S 0.75 L/kg and in the column experiment at L/S 4 L/kg is assumed to be related to decreasing concentrations of Ca and thus to the dissolution of sparingly soluble calcium antimonate. The same leaching mechanism applies with V, but the concentration levels observed are less critical regarding relevant limit values. However, on the long term the behavior of Sb could be problematic for the application of MSWI BA in construction.
Over the past two decades, per- and polyfluoroalkyl substances (PFASs) have emerged as worldwide environmental contaminants, calling out for sophisticated treatment, decomposition and remediation strategies. In order to mineralize PFAS pollutants, the incineration of contaminated material is a state-of-the-art process, but more cost-effective and sustainable technologies are inevitable for the future. Within this review, various methods for the reductive defluorination of PFASs were inspected. In addition to this, the role of mechanochemistry is highlighted with regard to its major potential in reductive defluorination reactions and degradation of pollutants. In order to get a comprehensive understanding of the involved reactions, their mechanistic pathways are pointed out. Comparisons between existing PFAS decomposition reactions and reductive approaches are discussed in detail, regarding their applicability in possible remediation processes. This article provides a solid overview of the most recent research methods and offers guidelines for future research directions.
The suitability of common analytical methods for the determination of active substances from wood preservatives in aged wood samples was investigated during an interlaboratory study. Permethrin, propiconazole and tebuconazole were quantified in 1.5 and 8 year-old wood samples by gas chromatography and liquid chromatography. Generally, the applied Methods yielded reliable results for these samples. However, wood components can coelute with propiconazole and tebuconazole during liquid chromatography. Optimization of separation might be required if UV detection is applied.
Phosphorus (P) resource availability is declining and the efficiency of applied nutrients in agricultural soils is becoming increasingly important. This is especially true for P fertilizers from recycled materials, which often have low plant availability. Specific co-fertilization with ammoniumcan enhance P plant availability in soils amended with these P fertilizers, and thus the yield of plants. To investigate this effect, we performed a pot experiment with maize in slightly acidic soil (pH 6.9) with one water-soluble (triple superphosphate [TSP]) and two water-insoluble (sewage sludge-based and hyperphosphate [Hyp]) P fertilizers and anammoniumsulfate nitrate with or without a nitrification inhibitor (NI). The dry matter yield of maize was significantly increased by the NI with the Hyp (from 14.7 to 21.5 g/pot) and TSP (from 40.0 to 45.4 g/pot) treatments. Furthermore, P uptake was slightly increased in all three P treatments with the NI, but not significantly. Olsen-P extraction and P K-edge micro-X-ray absorption near-edge structure (XANES) spectroscopy showed that apatite-P of the water insoluble P fertilizers mobilized during the plant growth period. In addition, novel nitrogen (N) K-edge micro-XANES spectroscopy and the Mogilevkina method showed that the application of an NI increased the fixation of ammonium in detectable hot spots in the soil. Thus, the delay in the nitrification process by the NI and the possible slow-release of temporarily fixed ammoniumin the soil resulted in a high amount of plant available Ammonium in the soil solution. This development probably decreases the rhizosphere pH due to release of H+ by plants during ammoniumuptake, whichmobilizes phosphorus in the amended soil and increases the dry matter yield of maize. This is especially important for water-insoluble apatite-based P fertilizers (conventional and recycled), which tend to have poor plant availability.
Bottom ash (BA) from municipal solid waste incineration (MSWI) contains harmful substances such as heavy metals, chloride and sulfate which are mobilized in contact with water. Standardized leaching tests are used to measure the extent of mobilization. It is known that fresh bottom ash displays elevated concentrations of various heavy metals such as lead or zinc due to the formation of hydroxo complexes as a result of high pH values of 12 and above. Storage of BA is accompanied by ageing processes, mainly the reaction of CaO and Ca(OH)2 with CO2 leading to lower pH values in contact with water around 11. Usually heavy metals concentrations are minimum at these conditions. Knowledge of the long-term leaching behavior of potentially harmful substances is crucial for the assessment of the environmental compatibility of reusing municipal solid-waste incineration bottom ash (MSWI BA) in construction, i.e., as a road base layer. BA fractions obtained from wet-processing aiming at the improvement of environmental quality were used to investigate the mobility of relevant substances. Eluates from laboratory-scaled leaching procedures (column percolation and lysimeters) were analyzed to learn about the long-term release of substances. Unsaturated conditions and artificial rainwater were used in the lysimeter tests to simulate field conditions. In addition, batch test eluates were generated at usual liquid-to-solid ratios (L/S) for compliance testing purposes. A variety of cations and anions was measured in the eluates. The wet treatment reduces the leaching of chloride and particularly sulfate by more than 60%. The release of typical contaminants for the treated MSWI BA such as the heavy metals Cu and Cr was well below 1% in the conducted leaching tests. An increase in the Sb concentration was observed in the lysimeter experiments starting at L/S 0.75 L/kg and in the column experiment at L/S 4 L/kg is assumed to be related to decreasing concentrations of Ca and thus to the dissolution of sparingly soluble calcium antimonate. The same leaching mechanism applies with V, but the concentration levels observed are less critical regarding relevant limit values. However, on the long term the behavior of Sb could be problematic for the application of MSWI BA as secondary building material.
Municipal solid waste incineration (MSWI) is one of the leading technologies for municipal solid waste (MSW) treatment in Europe. Incineration bottom ash (IBA) is the main solid residue from MSWI, and its annual European production is about 20 million tons. The composition of IBA depends on the composition of the incinerated waste; therefore, it may contain significant amounts of ferrous and non-ferrous (NFe) metals as well as glass that can be recovered. Technologies for NFe metals recovery have emerged in IBA treatment since the 1990s and became common practice in many developed countries. Although the principles and used apparatus are nearly the same in all treatment trains, the differences in technological approaches to recovery of valuable components from IBA – with a special focus on NFe metals recovery – are summarized in this paper.
Almost 500 municipal solid waste incineration plants in the EU, Norway and Switzerland generate about 17.6 Mt/a of incinerator bottom ash (IBA). IBA contains minerals and metals. Metals are mostly separated and sold to the scrap market and minerals are either disposed of in landfills or utilised in the construction sector. Since there is no uniform regulation for IBA utilisation at EU level, countries developed own rules with varying requirements for utilisation. As a result from a cooperation network between European experts an up-to-date overview of documents regulating IBA utilisation is presented. Furthermore, this work highlights the different requirements that have to be considered. Overall, 51 different parameters for the total content and 36 different parameters for the emission by leaching are defined. An analysis of the defined parameter reveals that leaching parameters are significantly more to be considered compared to total content parameters. In order to assess the leaching behaviour nine different leaching tests, including batch tests, up-flow percolation tests and one diffusion test (monolithic materials) are in place.
A further discussion of leaching parameters showed that certain countries took over limit values initially defined for landfills for inert waste and adopted them for IBA utilisation. The overall utilisation rate of IBA in construction works is approximately 54 wt%. It is revealed that the rate of utilisation does not necessarily depend on how well regulated IBA utilisation is, but rather seems to be a result of political commitment for IBA recycling and economically interesting circumstances.
In 2018, the production of Municipal SolidWaste (MSW) in EU-28 reached 250.6 Mt, with the adoption of different management strategies, involving recycling (48 wt %), incineration and thermal valorization (29 wt %) and landfilling (23 wt %). This work was based on the analysis of the baseline situation of MSW management in EU-28 in 2018, considering its progress in 2008–2018, and discussed the possible improvement perspectives based on a framework involving incineration and recycling as the only possible alternatives, specifically evaluating the capability of already-existing incineration plants to fulfill the EU needs in the proposed framework. The results of the assessment showed two main crucial issues that could play a pivotal role in the achievement of Circular Economy action plan targets: the need to increase the recycling quotas for specific MSW fractions through the separate collection, and therefore the improvement of definite treatment process chains; the optimization of the recovery of secondary raw materials from incineration bottom ash, involving the Recycling of ferrous and nonferrous metals and the mineral fraction. Both issues need to find an extensive application across all member states to decrease the actual differences in the adoption of sustainable MSW management options.
Per- and polyfluoralkyl surfactants (PFASs) are industrially produced surface chemicals used in daily applications that have gained public and political attention due their unnaturally high appearance in drinking water, nourishments and soils. Their chemical structures exhibit both lipophilic and hydrophilic properties, leading to a highly inert and persistent character. Various PFASs have shown to be bioaccumulative in plants and animals, and some have been characterized as highly toxic when ingested. When exposed to the environment, PFASs slowly get mobilized by natural water resources, leading to contamination of large areas of soil and natural water sources. While PFASs contamination of drinking water has been investigated intensively, perfluoralkyl contamination of soils has been rarely examined as of yet. At the same time, an increasing amount of PFASs contamination sites are being discovered worldwide, calling for a sophisticated strategy towards analytical characterization. Since the number of known PFASs already exceeds 4700, the established sum parameters like extractable organic fluorine (EOF) and adsorbable organic fluorine (AOF) are key elements to fully survey the impact of exposure. Simultaneously, innovative soil remediation strategies are required to contain environmental destruction and to minimize further
spreading of contaminants. Addressing these challenges requires suitable analytical devices that are capable of mobilizing PFASs in the solid as well as in the liquid phase. The use of combustion ion
chromatography (CIC) enables analysis of both immobile and volatile PFASs and allows the detection of both total fluorine (TF) and EOF or AOF of a given soil or aqueous sample. Based on preliminary results, the clean-up of a PFAS contaminated solid matrix is monitored via EOF detection over time.
Additionally, we demonstrate the pH dependency of hydrogen fluoride absorption on active carbon (AC) and found a simple organic additive to be an effective fluoride scavenger. The presented findings can be contributive with regard to future AOF/EOF sum parameter development and application.
Abstract: Since it is unknown for many applications, which PFASs are used and how they enter the environment, target analysis-based methods reach their limits. The two most frequently used sum parameters are the adsorbable organically bound fluorine (AOF) and the extractable organically bound fluorine (EOF). Both can be quantified using either combustion ion chromatography (CIC) or high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). Here we provide an insight on the advantageous and disadvantageous of both sum parameters and both detection methods. Our study is based on the analysis of surface water samples. Next to total fluorine (TF) analysis, AOF and EOF were determined as well as CIC and HR-CS-GFMAS are compared and results are comparatively discussed. Fluorine mass balancing revealed that, the AOF/TF proportion was higher than the EOF/TF proportion. The AOF made up 0.14–0.81% of TF and the EOF 0.04–0.28% of TF. Although, organically bound fluorine represents only a small portion of TF, PFASs are of worldwide concern, because of their extreme persistence and their bioaccumulation potential. The EOF-HR-CS-GFMAS method turned out to be more precise and sensitive than the AOF-CIC method and is a promising tool for future monitoring studies/routine analysis of PFASs in the environment.
Antimony in incineration bottom ash – Leaching behavior and conclusions for treatment processes
(2020)
Antimony (Sb) is used in industrial products mainly as flame retardant in plastic material. Due to such additives in plastics, about a half of Sb ends up in municipal solid waste incineration at the end-of-life and consequently in relevant amounts in the generated bottom ash. In contact with water, the initial leachability is low, as antimonates form sparingly soluble compounds with Ca2+. Following the carbonation of the incineration bottom ash (IBA) during the proceeding ageing the pH in the leachates decreases. With decreasing concentration of Ca in the eluate the solution equilibrium changes and antimonates dissolve. In Germany it is intended to regulate Sb in IBA with the planned implementation of the so called Mantelverordnung (MantelVO, containing provisions on the utilisation of mineral waste) in the near future. The limit values set in the draft might be critical for IBA and therefore pose a risk for the utilisation of the mineral fraction of IBA in the well-established recycling routes.
Innovation Network PerFluSan
(2020)
Per- and polyfluorinated alkyl substances (PFAS) are transferred into the environment as part of their broad industrial use, where they pose a problem due to their critical properties. The sustainable protection of people and the environment from this group of substances is an important task for the future. However, available PFAS removal and remediation processes are expensive and often inadequate. PerFluSan would like to make a relevant contribution to solve this problem by developing new PFAS remediation methods for soils and water, as well as innovative analytical methods for PFAS detection.
The long-term vision is to develop PerFluSan into a national contact point for the PFAS topic, which uses synergies between the PerFluSan actors to address all aspects of the problem holistically, sustainably and effectively.
Designing the performance of geogrids in reinforce soil constructions usually does not consider long-term behavior and possible failure modes of junctions between longitudinal and transverse ribs. How could behavior of junctions be included? To which extend is it necessary? On the conference Geo-Chicago 2016, Swan and Yuan presented an ultimate limit state equation for the short-term material resistance of junctions. We discuss limitations and suggest improvements to include long-term behavior of junctions. Nevertheless, the approach applies only to a specific mode of shear-tensile failure of junctions and only to strictly rigid geogrids. A new design concept presented in the same year by Jacobs on the conference GeoAmerica for the special case of the anchorage of geogrids, which reinforce capping system on long and steep slopes of landfills, tried to overcome these drawbacks. We discuss the aspects of this concept related to the long-term behavior
of junctions and the interplay between the load applied to junctions and the flexibility of longitudinal ribs. This interplay and the long-term junction strength determine the long-term behavior of geogrids.
In this study, we compare combustion ion chromatography (CIC) and high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) with respect to their applicability for determining organically Bound fluorine sum parameters. Extractable (EOF) and adsorbable (AOF) organically bound fluorine as well as total fluorine (TF) were measured in samples fromriver Spree in Berlin, Germany, to reveal the advantages and disadvantages of the two techniques used as well as the two established fluorine sum Parameters AOF and EOF. TF concentrations determined via HR-CS-GFMAS and CIC were comparable between 148 and 270 μg/L. On average, AOF concentrations were higher than EOF concentrations, with AOF making up 0.14–0.81% of TF (determined using CIC) and EOF 0.04–0.28% of TF (determined using HR-CSGFMAS).
The results obtained by the two independent methods were in good agreement. It turned out that HR-CS-GFMAS is a more sensitive and precise method for fluorine analysis compared to CIC. EOF and AOF are comparable tools in Risk evaluation for the emerging pollutants per- and polyfluorinated alkyl substances; however, EOF is much faster to conduct.
This work is aimed at exploring the recovery of heavy metals from the fine fraction of solid waste incineration bottom ash.
For this study, wet-discharged bottom ash fine-fraction samples from full-scale treatment plants in Germany and Sweden were analyzed. The potential for the recovery of heavy metal compounds was investigated through wet density-separation with a shaking table. The feed materials were processed without any pre-treatment and the optimum processing conditions were determined by means of design of experiments. Tilt angle and stroke frequency were identified as the most relevant parameters, and the optimum settings were − 7.5° and 266 rpm, respectively. The obtained balanced copper enrichments (and yields) were 4.4 (41%), 6.2 (28%) and 2.4 (23%). A maximum copper enrichment of 14.5 with 2% yield was achieved, providing a concentrate containing 35.9 wt.% relevant heavy metal elements. This included 26.3 wt.% iron, 4.3 wt.% zinc and 3.8 wt.% copper. In conclusion, density separation with shaking tables can recover heavy metals from bottom ash fine fractions. Medium levels of heavy metal enrichment (e.g., for Cu 2.7–4.4) and yield (Cu: 26–41%) can be reached simultaneously.
However, the separation performance also depends on the individual bottom ash sample.
The concept of circular economy supports mitigation of climate change and other environmental pressures to the planet. Circulating materials in anthropogenic processes come with the risk of accumulating hazardous substances and compounds. In this concept, waste incineration or waste-to-energy (WtE) is a necessary technology to remove these compounds from the life cycle. In this mini-review, contaminants of major importance in the flue gas from waste incineration plants and their environmental impact are discussed. Air pollution of WtE is often seen as the most relevant environmental impact of this treatment option. The emission values parameter set for different countries is presented and compared. The most stringent legally set of emission values could be found in parts of Europe and South Korea. Japan also permits similar strict values when authorising individual incineration plants. In North America, the values are partially less strict as the best available technologies in Europe suggest being possible. Emerging economies, such as India and China, have shown efforts to improve their environmental protection standards but still have room to improve. This could be set in relation to other industrial emitting processes and therefore could be used to assess the relevance of this industry sector to the national emission inventories.
2021 marks the 10th anniversary of the first ERA.Net RUS joint call for European-Russian STI cooperation projects. Pooling the resources of more than 20 European and Russian funding agencies, more than 150 projects were funded with an estimated budget of about € 60 million.
Being even larger than many thematic ERA.NETs, the ERA.Net RUS Plus has been the biggest and most successful regional ERA.NET so far. Indicating a strong demand for scientific cooperation, the smaller-scale projects funded within the ERA.Net RUS (Plus) calls perfectly complement Russian participation in the EU Framework Programmes.
Not least of all, the ERA-Net RUS calls are examples of successful collaboration at a time when cooperation in other fields is complicated by the politically challenging situation. These calls contributed to keeping the communication channels open.
Against this background a dedicated event in late 2021 highlighted what has been achieved within the first decade of the initiative. The project EI-GEO coordinated by BAM was selected as best practice project. The presentation displays the main results of the project and discusses the key success factors.
For the first time, fluorine K-edge X-ray absorption near-edge structure (XANES) spectroscopy was applied to detect per- and polyfluoroalkyl substances (PFAS) in various soil and sewage sludge samples. The method can be used to determine the speciation of inorganic and organic fluorides, without pre-treatment of solid samples. Therefore, XANES spectra of several inorganic fluorides as well as selected fluorinated organic compounds were recorded. While inorganic fluorides partially exhibit a variety of sharp spectral features in the XANES spectrum, almost all inspected organofluorine compounds show two distinct broad features at 688.5 and 692.0 eV. Moreover, the peak intensity ratio 688.5 eV/692.0 eV in the PFAS XANES spectrum can be inversely correlated to the chain length of the perfluoro sulfonic acid group. The detection of targeted PFAS by bulk-XANES spectroscopy in combination with linear combination fitting in soils and sewage sludges was not applicable due to the low organic fluorine to total fluorine ratio of the samples (0.01–1.84%). Nonetheless, direct analysis of pure PFAS revealed that analysis of organofluorine species might be achieved in higher concentrated samples. Furthermore, quantitative measurements by combustion ion chromatography (CIC) evaluated as sum parameters extractable organically bound fluorine (EOF) and total fluorine (TF) emphasize that besides soils, sewage sludges are a significant source of organic fluorine in agriculture (154–7209 μg/kg).
Microspectroscopy reveals dust-derived apatite grains in acidic, highly-weathered Hawaiian soils
(2021)
Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic Gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradient were analyzed with bulk (X-ray diffraction and P K-edge X-ray absorption near edge structure) and microscale (X-ray fluorescence, P K-edge X-ray absorption near edge structure, and Raman) analysis methods. In the wettest soils, apatite grains ranging from 5 to 30 μm in size were co-located at the micro-scale with quartz, a known continental dust indicator suggesting recent atmospheric deposition. In addition to co-location with quartz, further evidence of dust-derived P included backward trajectory modeling indicating that dust particles could be brought to Hawaii from the major global dust-loading areas in central Asia and northern Africa. Although it is not certain whether the individual observed apatite grains were derived from long-distance transport of dust, or from local dust sources such as volcanic ash or windblown fertilizer, these observations offer direct evidence that P-containing minerals have reached surface layers of highly-weathered grassland soils through atmospheric deposition.
This paper focuses on the scandium speciation in bauxite residues of different origin. Insights into mineralchemical similarities and differences of these materials will be presented and links to their natural geological background discussed. The presented research should provide fundamental knowledge for the future development of efficient and viable technologies for Sc-recovery from bauxite residues derived from different bauxites and accumulating at different localities. In total, five bauxite residues were investigated which originated from Greece, Germany, Hungary and Russia (North Ural & North Timan) using a combination of different analytical tools. Those included: laser ablation inductively coupled plasma mass spectrometry, X-ray absorption near Edge structure (XANES) spectroscopy, μ-Raman spectroscopy as well as scanning electron microscopy and electron microprobe analyses. X-ray fluorescence and inductively coupled plasma mass spectrometry were used to determine the overall chemical composition. The investigated samples were found to exhibit a relatively homogenous distribution of Sc between the larger mineral particles and the fine-grained matrix except for Al-phases like diaspore, boehmite and gibbsite. These phases were found to be particularly low in Sc. The only sample where Sc mass fractions in Al-phases exceeded 50 mg/kg was the Russian sample from North Ural. Fe-phases such as goethite, hematite and chamosite (for Russian samples) were more enriched in Sc than the Al-phases.
In fact, in Greek samples goethite showed a higher capacity to incorporate or adsorb Sc than hematite. Accessory minerals like zircon, rutile/anatase and ilmenite were found to incorporate higher mass fractions of Sc (>150 mg/kg), however, those minerals are only present in small amounts and do not represent major host phases for Sc. In Russian samples from North Ural an additional Ca–Mg rich phase was found to contain significant mass fractions of Sc (>500 mg/kg). μ-XANES spectroscopy was able to show that Sc in bauxite residue occurs adsorbed onto mineral surfaces as well as incorporated into the crystal lattice of certain Fe-phases. According to our observations the bauxite type, i.e. karstic or lateritic, the atmospheric conditions during bauxitization, i.e. oxidizing or reducing, and consequently the dominant Sc-bearing species in the primary Bauxite influence the occurrence of Sc in bauxite residues. In karstic bauxites, underlying carbonate rocks can work as a pH-barrier and stabilize Sc. This prevents the Sc from being mobilized and removed during bauxitization. Hence, karstic bauxites are more prone to show a Sc enrichment than lateritic bauxites. Reducing conditions during bauxitization support the incorporation of Sc into clay minerals such as chamosite, which can dissolve and reprecipitate during Bayer processing causing Sc to be redistributed and primarily adsorb onto mineral surfaces in the bauxite residue. Oxidizing conditions support the incorporation of Sc into the crystal lattice of Fe-oxides and hydroxides, which are not affected in the Bayer process. The genetic history of the bauxite is therefore the major influential factor for the Sc occurrence in bauxite residues.
The main obstacle to bottom ash (BA) being used as a recycling aggregate is the content of salts and potential toxic elements (PTEs), concentrated in a layer that coats BA particles. This work presents a dry treatment for the removal of salts and PTEs from BA particles. Two pilotscale abrasion units (with/without the removal of the fine particles) were fed with different BA samples. The performance of the abrasion tests was assessed through the analyses of particle size and moisture, and that of the column leaching tests at solid-to-liquid ratios between 0.3 and 4.
The results were: the particle-size distribution of the treated materials was homogeneous (25 wt % had dimensions <6.3 mm) and their moisture halved, as well as the electrical conductivity of the leachates. A significant decrease was observed in the leachates of the treated BA for sulphates (44%), chlorides (26%), and PTEs (53% Cr, 60% Cu and 8% Mo). The statistical analysis revealed good correlations between chloride and sulphate concentrations in the leachates with Ba, Cu, Mo, and Sr, illustrating the consistent behavior of the major and minor components of the layer surrounding BA particles. In conclusion, the tested process could be considered as promising for the improvement of BA valorization.
Geosynthetic materials are applied in measures for coastal protection. Weathering or any damage of constructions, as shown by a field study in Kaliningrad Oblast (Russia), could lead to the littering of the beach or the sea (marine littering) and the discharge of possibly harmful additives into the marine environment. The ageing behavior of a widely used geotextile made of polypropylene was studied by artificial accelerated ageing in water-filled autoclaves at temperatures of 30 to 80 °C and pressures of 10 to 50 bar. Tensile strength tests were used to evaluate the progress of ageing, concluding that temperature rather than pressure was the main factor influencing the ageing of geotextiles. Using a modified Arrhenius equation, it was possible to calculate the half-life for the loss of 50% of the strain, which corresponds to approximately 330 years. Dynamic surface leaching and ecotoxicological tests were performed to determine the possible release of contaminants. No harmful effects on the test organisms were observed.
Throughout their life cycle—from production, via usage, through to disposal—materials and products interact with the environment (water, soil, air). At the same time, they are exposed to environmental influences and, through their emissions, have an impact on the environment, people, and health. Accelerated experimental testing processes can be used to predict the long-term environmental consequences of innovative products before these actually enter the environment.
The aim of this Special Issue of the journal Materials is to publish original research and review articles as well as short communications tackling the problem of reliable environmental measurement methods and reporting exemplary case studies.
In this study, nanoscopic particles of magnesium Fluoride (MgF2) and calcium fluoride (CaF2) also known as nano metal fluorides (NMFs), were evaluated for their potential to improve wood durability. Even though these fluorides are sparingly soluble, their synthesis in the form of nano-sized particles turns them into promising candidates for wood preservation. Their distinct property of low-water solubility is proposed to maintain long-lasting protection of treated wood by reducing the leaching of fluoride. Analytical methods were used to characterize the synthesized NMFs and their distribution in treated wood specimens. Transmission electron microscopy images showed that these fluoride particles are smaller than 10 nm. In nano metal fluoride (NMF) treated specimens, aggregates of these particles are uniformly distributed in the wood matrix as confirmed with scanning electron microscopy images and their corresponding energy-dispersive X-ray spectroscopy maps. The fluoride aggregates form a protective layer around the tracheid walls and block the bordered pits, thus reducing the possible flow path for water absorption into wood. This is reflected in the reduced swelling and increased hydrophobicity of wood treated with NMFs. The biocidal efficacy of NMFs was tested against brown-rot fungi (Coniophora puteanaand Rhodonia placenta), white-rot fungus (Trametes versicolor), and termites (Coptotermes formosanus). The fungal and termite tests were performed in accordance with the EN 113 (1996) and EN 117 (2012) standards, respectively. Prior to fungal tests, the NMF treated wood specimens were leached according to the EN 84 (1997)standard. Compared to untreated specimens, the NMF treated wood specimens have a higher resistance to decay caused by brown-rot fungi, white-rot fungus, and termites. Although all NMF treatments in wood reduce the mass loss caused by fungal decay, only the combined treatment of MgF2 and CaF2 has efficacy against both brown-rot fungi and white-rot fungus. Similarly, wood treated with the combined NMF formulation is the least susceptible to attack by C. formosanus.It is proposed that combining MgF2 and CaF2changes their overall solubility to promote the release of fluoride ions at the optimal concentration needed for biocidal efficacy against fungi and termites. In this thesis, it was proven that even after leaching, sufficient fluoride was present to protect NMF treated wood from fungal decay. This shows that NMFs are robust enough for above ground contact outdoor applications of wood, where permanent wetness cannot be avoided according to Use Class 3.2, as per the EN 335 (2013) standard. Also, they pose a low risk to human health and the environment because they are sparingly soluble. Since NMFs significantly reduce the decay of wood, the CO2 fixed in it will be retained for longer than in unpreserved wood. Overall, the novel results of this study show the potential of NMFs to increase the service life of building materials made from non-durable wood.
Per- and polyfluoroalkyl substances (PFAS) have been used extensively in the past because of their inert chemical character and resistance to degradation by environmental influences. Since the beginning of their commercial use, PFAS have been widely exposed to the environment by application of PFAS in consumer products or as foaming agent in firefighting foams, thus several cases of contaminated soils sites have been reported. Since the number of known PFAS already exceeds 4700, their characterization and direct analysis is challenging given the current available techniques. Here, we introduce the novel fluorine (F) K-edge X-ray absorption near-edge structure (XANES) spectroscopy as a tool to analyze PFAS and inorganic fluorine compounds in contaminated soils and sewage sludges. While F K-edge bulk-XANES spectroscopy provide us information on the overall fluorine bonding in a sample micro X-ray fluorescence (XRF) in combination with F K-edge micro-XANES spectroscopy can also detect minor fluorine compounds and PFAS hotspots in investigated soils and sludges. Additionally, we used the combustion ion chromatography (CIC) to analyze the total amount of all PFAS as a sum parameter (extractable organic fluoride: EOF) in soils and sewage sludges. During combustion in the CIC, the PFAS in the sample get destroyed at temperatures of approx. 1000 °C and converted in inorganic fluorides that subsequently gets quantified by ion chromatography. Thus, for the first time we successfully combined F K-edge XANES spectroscopy and CIC as analytical tools to detect and quantify PFAS contaminants in soils and sewage sludges.
Phosphorus (P) resource availability and quality is declining and recycling P-fertilizers from waste materials are becoming increasingly important. One important secondary P resource is sewage sludge (SSL) where P is often bound as aluminum phosphate (Al-P), iron phosphate (Fe-P) and polyphosphate (poly-P), respectively. Thermal treatment in different ways is a promising way in P recycling to produce highly plant-available P-fertilizers. To investigate mechanisms behind transformation of hardly available P-species toward plant-available P forms we treated a model SSL containing different kinds of defined P sources by low-temperature conversion (LTC) at 500 °C and subsequent thermochemical treatment of the LTC product with Na additives (TCT) at 950 °C, respectively. Pot experiments with ryegrass were carried out to determine the plant availability of P of the different treatments. The poly-P (here pyrophosphates) based fertilizers had a very high plant availability after both thermal treatments. During LTC treatment the plant availability of the Fe-P and Al-P variants increased because of the Formation of Fe(II) phosphates and/or pyro-/polyphosphates. Especially the formation of Al-polyphosphate shows a high plant availability. The subsequent TCT further increased strongly the plant availability of the Fe-P variants because of the formation of highly plant-available CaNaPO4. Thus, a direct TCT without prior LTC probably also produce CaNaPO4 and is recommended for Fe-P based SSL. However, a molar Ca/P ratio of 1 in the fertilizer is favorable for CaNaPO4 formation. Thus, the knowledge on the source of primary P in SSL is essential for choosing the accurate thermal treatment method to produce highly plant-available P-fertilizers from SSL.
Due to its large mineral fraction, incineration bottom ash (IBA) from municipal solid waste incineration is an interesting raw material that can be used for road construction or to produce secondary building materials. However, leaching chloride, sulfate, and potentially harmful heavy metals may cause problems in using IBA in civil engineering. Investigating leaching behavior is crucial for the assessment of the environmental compatibility of IBA applications. Various test procedures are available for that purpose. In the present study, a long-term leaching test of a wet-mechanically treated IBA was performed in a lysimeter for almost six years.
While concentrations of chloride, sulfate and the majority of the heavy metals started to decrease rapidly with progressive liquid-to-solid ratio (L/S), antimony (Sb) and vanadium (V) behaved differently. At the beginning of the lysimeter test, the Sb and V concentrations were low, but after approximately one year of operation at an L/S ratio of around 0.8 L/kg, a steady increase was observed. It was shown that this increase is the result of low Ca concentrations due to the formation of CaCO3.
With the data, the solubility products from Ca-antimonate and Ca-vanadate were calculated. The unusual leaching behavior of Sb and V should be kept in mind when considering field scenarios and evaluating the impact on the environment.
A wide range of analytical methods are used to estimate the plant-availability of soil phosphorus (P). Previous investigations showed that analytical methods based on the Diffusive Gradients in Thin films (DGT) technique provide a very good correlations to the amount of bioavailable nutrients and pollutants in environmental samples (Davison 2016, Vogel et al. 2017). However, the DGT results do not identify which P compound of the soil has the high bioavailability. But there are various spectroscopic techniques (infrared, Raman, P K-edge and L-edge XANES and P NMR spectroscopy) available to characterize P species in soils. Therefore, spectroscopic investigation of DGT binding layers after deployment allow us to determine the specific compounds. Nutrients such as phosphorus and nitrogen are often, together with other elements, present as molecules in the environment. These ions are detectable and distinguishable by infrared, P K- and L-edge X-ray absorption near-edge structure (XANES) and NMR spectroscopy, respectively. Additionally, microspectroscopic techniques make it also possible to analyze P compounds on the DGT binding layer with a lateral resolution down to 1 μm2. Therefore, species of elements and compounds of e.g. a spatial soil segment (e.g. rhizosphere) can be mapped and analyzed, providing valuable insight to understand the dynamics of nutrients in the environment.
The aim of this study was to investigate the passive sampler method Diffusive Gradients in Thin-films (DGT) for ammonium and nitrate in amended soils. Therefore, we used soils from a pot experiment with maize where nitrogen (N) was supplied as ammonium sulfate nitrate (ASN), without and with a nitrification inhibitor (NI). The additional use of a NI can delay the nitrification in the soil and making the ammonium available for a longer period in the soil solution after its application. Homogenized soil samples were collected directly from each pot after one week of incubation before sowing and after harvesting the maize. Nitrate and ammonium in these soil samples were extracted using DGT devices equipped with a Putolite A520E (for nitrate) and Microlite PrCH (for ammonium) binding layer. Ammonium DGT which determined the mobile and labile ammonium forms based on diffusion and the resupplies from the solid soil phase, only showed a significantly higher amount of extractable ammonium with NI compared to that without NI for some samples. However, significantly lower values were found for nitrate of treatments with NI compared to without NI after harvest. Thus, the lower nitrate amounts for treatments with NI compared to the treatments without NI after harvest indicated the delay of the nitrification process by the NI. Furthermore, we compared also the ammonium and nitrate
DGT results to chemical extraction with KCl solutions. The results demonstrated that the trends of DGT results and chemical extraction were complimentary through all the treatments.
Phosphorus (P) fertilizers from secondary resources became increasingly important in the last years. However, these novel P-fertilizers can also contain toxic pollutants. Chromium in its hexavalent state (Cr(VI)) is regulated with low limit values for agricultural products due to its high toxicity, but the determination of Cr(VI) in these novel fertilizer matrices can be hampered by redox processes that lead to false results. Thus, we applied the passive sampler technique Diffusive Gradients in Thin-films (DGT) for the determination of Cr(VI) in fertilizers and compared the results with the standard wet chemical extraction method (German norm DIN EN 15192) and Cr K-edge X-ray absorption near-edge structure (XANES) spectroscopy. We determined an overall good correlation between the wet chemical extraction and the DGT method. DGT was very sensitive and in most cases selective for the analysis of Cr(VI) in P-fertilizers. However, hardly soluble Cr(VI) compounds cannot be detected with the DGT method since only mobile Cr(VI) is analyzed. Furthermore, Cr K-edge XANES spectroscopy showed that the DGT binding layer also adsorbs small amounts of mobile Cr(III) compounds which leads to overestimated Cr(VI) values. The results of certain types of P-fertilizers containing mobile Cr(III) or partly immobile Cr(VI), showed that optimization of the DGT method is required to avoid over- or underestimation of Cr(VI).
In Europe, nearly 19 Mt/y of bottom ash (BA) are produced. Of this quota, only 46 %wt. was treated, often in poorly performing plants, leaving behind 10 Mt of untreated and unrecovered BA, destined to landfill. The resulting 2.14 Mt loss of valuable materials included 1 Mt mineral fraction and 0.97 Mt ferrous metals, mostly from untreated BA, and 0.18 Mt non-ferrous metals, mostly from unrecovered BA. For the coarser fractions, the main obstacle to BA being used as recycling aggregate is the content of salts and potential toxic elements (PTEs), concentrated in a layer that coats BA particles. For the fine BA fractions, usually underexploited and landfilled, it is estimated that up to 0.95 Mt/y of ferrous and non-ferrous metals are not recovered in Europe.
During the workshop, the key results of BASH Treat project will be presented: the results of 2 industrial tests performed in BA treatment plants in Germany and Sweden; a novel dry treatment for the removal of salts and PTEs from BA coarse particles; a wet process for the recovery of heavy metal compounds from the fine fraction; a technical-economic assessment of the EU potential for the optimization of BA management.
In 2018 municipal solid waste (MSW) incineration in Europe produced nearly 19 Mt of bottom ash (BA); only 46 %-wt. was treated, often in poorly performing plants, leaving behind 10 Mt of untreated and unrecovered BA, destined to landfill. This work was based on the inventory of BA across Europe, and on the hypothesis to achieve complete BA valorisation through two assumptions: treating 100% BA and minimizing the loss of valuable fractions due to technical limitations of state-of-the-art processes in comparison to advanced innovative processes. The research involved three phases: characterization of potential secondary raw materials (metals and mineral fraction) currently lost from untreated (the surplus compared to treatment capacity) and unrecovered BA (the fine fraction) through material flow analysis; environmental assessment (energy balance and net GHG emissions) of complete BA valorisation; investigation of the economic feasibility of complete BA Valorisation through state-of-the-art technologies. The resulting 2.14 Mt loss of valuable materials included 1 Mt Mineral fraction and 0.97 Mt ferrous metals, mostly from untreated BA, and 0.18 Mt non-ferrous metals, mostly from unrecovered BA. The energy balance and GHGs emissions required by the treatment of the currently untreated and unrecovered fractions of BA resulted in energy and GHGs emissions savings. Economic profitability was driven by iron and copper recycling and avoided landfill fees. Profitability was achieved by two thirds of considered countries (average values: NPV 83 M€, ROI 20%, payback time 11 years) with BA mass flow exceeding 0.02 Mt.
Background
A European inter-laboratory test with 29 participating laboratories investigated whether a battery of four ecotoxicological tests is suitable for assessing the environmental compatibility of construction products. For this purpose, a construction product was investigated with the dynamic surface leaching test (DIN CEN/TS 16637-2) and the percolation test (DIN CEN/TS 16637-3). The eluates were produced centrally by one laboratory and were tested by the participants using the following biotests: algae test (ISO 8692), acute daphnia test (ISO 6341), luminescent bacteria test (DIN EN ISO 11348), and fish egg test (DIN EN ISO 15088). As toxicity measures, EC50 and LID values were calculated.
Results
Toxic effects of the eluates were detected by all four biotests. The bacteria test was by far the most sensitive, followed by the algae test and the daphnia test; the fish egg test was the least sensitive for eluates of both leaching tests. The toxicity level of the eluates was very high in the bacteria, daphnia, and algae test, with lowest ineffective dilution values of LID = 70 to LID = 13,000 and corresponding EC50 values around or even below 1 volume percent. The reproducibility (approximated by interlaboratory variability) of the biotests was good (< 53%) to very good (< 20%), regardless of the toxicity level of the eluates. The reproducibility of the algae test was up to 80%, and thus still acceptable.
Conclusion
It can be confirmed that the combination of leaching and ecotoxicity tests is suitable to characterize with sufficient reproducibility the environmental impact posed by the release of hazardous substances from construction products.
Stormwater from urban areas can transport biocidally active substances and related transformation products from buildings into the environment. The occurrence of these substances in urban runoff depends on the availability of water, and on ultraviolet radiation exposure that causes photolytic reactions. In a systematic laboratory study, painted test specimens were exposed to either ultraviolet radiation, water contact, or a combination of both. Leaching of the biocidally active substances carbendazim, diuron, octylisothiazolinone, terbutryn, and selected transformation products of terbutryn and diuron were observed under various exposure conditions. Remaining concentrations of these substances in the paint were quantified. It was demonstrated that the distribution of active substances and transformation products in eluates and in the coatings themselves differs with exposure conditions. Strategies for environmental monitoring of biocide emissions need to consider the most relevant transformation products. However, environmental concentrations of biocidally active substances and transformation products depend on earlier exposure conditions. As a consequence, monitoring data cannot describe emission processes and predict expected leaching of biocidally active substances from buildings if the data are collected only occasionally.
Per- and polyfluoralkyl surfactants (PFAS) are industrially produced surface chemicals used in daily applications that have gained public and political attention due their unnaturally high appearance in drinking water, nourishments and soils.[1] Their chemical structures exhibit both lipophilic and hydrophilic properties, leading to a highly inert and persistent character.[2] Various PFAS have shown to be bioaccumulative in plants and animals, and some have been characterized as highly toxic when ingested.[3] When exposed to the environment, PFAS slowly get mobilized by natural water resources, leading to contamination of large areas of soil and natural water sources.[4] While PFAS contamination of drinking water has been investigated intensively, perfluoralkyl contamination of soils has been rarely examined as of yet. At the same time, an increasing amount of PFAS contamination sites are being discovered worldwide, calling for a sophisticated strategy towards analytical characterization.[5] Since the number of known PFAS already exceeds 4700, the established sum parameters like extractable organic fluorine (EOF) and adsorbable organic fluorine (AOF) are key elements to fully survey the impact of exposure.[6] Simultaneously, innovative soil remediation strategies are required to contain environmental destruction and to minimize further spreading of contaminants.[7] Addressing these challenges requires suitable analytical devices that are capable of mobilizing PFAS in the solid as well as in the liquid phase. The use of combustion ion chromatography (CIC) enables analysis of both immobile and volatile PFAS and allows the detection of both total fluorine (TF) and EOF or AOF of a given soil or aqueous sample. Based on preliminary results, the clean-up of a PFAS contaminated matrix is monitored via EOF detection over time. Additionally, we tested the effectiveness of urea (CH₄N₂O) as fluoride scavenger with the aim to improve the separation of inorganic and organic fluorine and therefore, to improve AOF accuracy. The presented findings can be contributive with regard to future AOF/EOF sum parameter development and application.
Several thousand PFAS are in circulation and the current challenge lies in detection of these compounds. Wheter environmental contamination occurs via industrial emission or direct PFAS exposure, as through the use of AFFF fire fighting foams. Wheter PFAS need to be detected in consumer products or agricultral soil, or wheter human and wildlife exposure to PFSA needs to be evaluated, suitable analytical methods are required to identifiy the target class within a hugh variety of matrices. At the same time it is critical to detect trace amounts of compounds within various matrices, we want to make sure that we consider very volatile and mobile species, simultaneously want to assure that we do not overlook less and insoluble compounds. We require methods that allow both single and multi target analysis and want to have an ideal overview with the help of sum parameters.
Here, we describe a fast and simple extraction method for the determination of per- and polyfluorinated alkyl substances (PFASs) utilizing extractable organic fluorine (EOF) sum parameter analysis and high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) in soil samples. After extraction and separation of inorganic and organic fluorinated compounds, organically bound fluorinated compounds were indirectly determined via the molecular absorption of gallium mono-fluoride at 211.248 nm. The implementation of the decisions of the “Stockholm Convention on persistent organic pollutants” as well as the “Protocol on Persistent Organic Pollutants of the Convention on Long-Range Transboundary Air Pollution” of the UNECE include the reduction respectively the elimination of PFASs in the environment. Currently, regulations aim to target single compounds (mostly C8-PFAS). But the PFAS group includes over 4700 substances, which are potentially persistent and toxic, thus target analytical approaches are not suitable for a holistic approach investigating the PFAS pollutant situation. Furthermore, forbidden PFASs are substituted by short-chain PFASs, thus the number of unknow substances is steadily increasing. For this reason, sum parameter approaches are more suitable to investigate and assess the pollution situation as well as derive exposure limits. Our developed analytical method was successfully applied to determine PFASs in soil samples from a polluted site. In view of steadily increasing numbers of PFAS substances, our method will make an important contribution in assessing the pollution situation as well as support policy makers in deriving exposure limits for PFAS in the future.
Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradient were analyzed with bulk (X-ray diffraction and P K-edge X-ray absorption near edge structure)
and microscale (X-ray fluorescence, P K-edge X-ray absorption near edge structure, and Raman) analysis methods. In the wettest soils, apatite grains ranging from 5 to 30 μm in size were co-located at the micro-scale with quartz, a known continental dust indicator suggesting recent atmospheric deposition. In addition to colocation with quartz, further evidence of dust-derived P included backward trajectory modeling indicating that dust particles could be brought to Hawaii from the major global dust-loading areas in central Asia and northern Africa. Although it is not certain whether the individual observed apatite grains were derived from long-distance transport of dust, or from local dust sources such as volcanic ash or windblown fertilizer, these observations offer direct evidence that P-containing minerals have reached surface layers of highly-weathered grassland soils
through atmospheric deposition.
The diffusive gradients in thin-films (DGT) technique shows in many publications a superior correlation to the amount of plant-available phosphorus (P) in soil. However, this technique cannot give information on the plant-available P species in soil. Therefore, we combined DGT with solution 31P nuclear magnetic resonance (NMR) spectroscopy. This was achieved by using a modified DGT device in which the diffusive layer had a larger pore size, the binding layer incorporated an adsorption material with a higher capacity, and the device had a larger exposure area. The spectroscopic investigation was undertaken after elution of the deployed DGT binding layer in a NaOH solution. Adsorption tests using solutions of known organic P compounds showed that a sufficient amount of these compounds could be adsorbed on the binding layer in order for them to be analyzed by solution 31P NMR spectroscopy. Furthermore, various intermediates of the hydrolysis of trimetaphosphate in soil could be also analyzed over time.
This Special Issue, ‘Measurement of the Environmental Impact of Materials’, is focused on the impact that materials have on the environmental compartments of soil, water and air. Leaching and emission processes, including underlying mechanisms, are a recurring topic in most published articles in the present Special Issue. Contributions have come from three continents and numerous countries (USA, Germany, France, Latvia, Poland, Russia, Japan, Korea and Thailand) indicating the global dimension of the subject.
The database gives information on the contamination of the shore of the South-Eastern Baltic with the debris of geosynthetic materials for the period 2018–2020. This new type of coastal pollution enters the natural environment due to the destruction of coastal protection structures and construction activities. The database contains sections:
(1) a list of types of geosynthetic material residues, their photographic images and photographs illustrating examples of finds in natural conditions
[1 List_geosynthetic_debris_SEB],
(2) monitoring data on the contamination of the beach strip with the debris of geotextiles, braids from gabions, geocontainers (big bags), geocells and geogrids for the beaches of the South-Eastern Baltic for the period 2018–2020
[2 Monitoring_geosynthetic_debris_SEB];
(3) statistical distributions of the found geosynthetic debris by size
[3 Scales_geosynthetic_debris_SEB] and (4) results of test surveys on the shores of Lithuania and Poland adjacent to Kaliningrad Oblast.
All data refer to the beaches of the Kaliningrad Oblast (Russia), including the Russian parts of the Vistula and Curonian Spits, but also contains information on a one-time assessment of the pollution of the beaches of the adjacent territories: the Polish shore from the Poland-Russia border on the Vistula Spit to the mouth of the Vistula River, the Lithuanian shore from the border Lithuania-Russia on the Curonian Spit to the border of Latvia-Lithuania. Materials were collected during field surveys within the ERANET-RUS_Plus joint project EI-GEO, ID 212 (RFBR 18-55-76002 ERA_a, BMBF 01DJ18005).
Buildings exposed to water can release undesirable substances which, once transported to environmental compartments, may cause unwanted effects. These exposure pathways need to be investigated and included in risk assessments to safeguard water quality and promote the sustainability of construction materials. The applied materials, exposure conditions, distribution routes and resilience of receiving compartments vary considerably. This demonstrates the need for a consistent concept that integrates knowledge of emission sources, leaching processes, transport pathways, and effects on targets. Such a consistent concept can serve as the basis for environmental risk assessment for several scenarios using experimentally determined emissions. Typically, a source–path–target concept integrates data from standardized leaching tests and models to describe leaching processes, the distribution of substances in the environment and the occurrence of substances at different points of compliance. This article presents an integrated concept for assessing the environmental impact of construction products on aquatic systems and unravels currently existing gaps and necessary actions. This manuscript outlines a source–path–target concept applicable to a large variety of construction products. It is intended to highlight key elements of a holistic evaluation concept that could assist authorities in developing procedures for environmental risk assessments and mitigation measures and identifying knowledge gaps.
Analytical Challenges for PFAS in Environmental Samples - Methods, Approaches and Applicability
(2022)
Per- and polyfluoroalkyl substances (PFAS) are anionic, cationic and zwitterionic synthetic products, in which the hydrogen atoms on the carbon skeleton of at least one carbon atom have been completely replaced by fluorine atoms and which include up to 1.7 M compounds, depending on the definition. As a result of continuous and prolific use, mainly in aviation firefighting foams, thousands of industrial and military installations have been found to contain contaminated soil, groundwater and surface water. Furthermore, because of the continuous contamination through PFAS containing commercial products, effluents and sewage sludge from WWTPs have been shown to be an important source of PFAS discharge into the aquatic environment. In the last few years, legacy PFAS (≥C4) have been found in various environments, including soil, water and wastewater, and their environmental pathways have been partly described.
Several long-chain PFAS species, and their respective salts are considered as persistent organic pollutants by the United Nations Stockholm Convention. These pollutants have been linked to altered immune and thyroid function, liver disease, lipid and insulin dysregulation, kidney disease, adverse reproductive and developmental outcomes, and cancer. A significant shift in the chemical industry towards production of short (C4-C7) and ultrashort (C1-C3) alternatives was observed in response to recently intensified regulations and restrictions on the use of long-chain (≥C8) PFAS. PFAS analysis in environmental samples is currently mainly done by liquid chromatography tandem mass spectrometry (LC-MS/MS). This efficient method is conducted in a targeted fashion analyzing a small subset of PFAS. The US EPA method for analysis of PFAS using LC-MS/MS for example currently lists 40 PFAS (≥C4). However, to get a better overview of the amount of “total PFAS,” sum parameter methods like total oxidizable precursor (TOP) assay and methods based on combustion ion chromatography (CIC) are in development. CIC results in data regarding the sum of absorbable organic fluorine (AOF) or extractable organic fluorine (EOF), which can also quantify other organically bound fluorine compounds such as fluorinated pesticides and pharmaceutical. Moreover, non-target and suspect screening mass spectrometry can be used to identify novel emerging PFAS and partly unknown fluorinated compounds in environmental samples. Furthermore, to analyze ultrashort PFAS (C1-C3), supercritical fluid chromatography (SFC), hydrophilic interaction chromatography (HILIC) and gas chromatography-mass spectrometry (GC-MS) are available, but further research is needed to develop reliable and accurate methods to quantify several ultrashort PFAS in environmental samples.
Additionally, for research purpose several spectroscopical methods like X-ray photoelectron spectroscopy (XPS), fluorine K-edge X-ray absorption near-edge structure (XANES)spectroscopy, particular induced gamma-ray emission (PIGE) spectroscopy and 19F nuclear magnetic resonance (NMR) spectroscopy are available.
Per- and polyfluoroalkyl substances (PFAS) are a large group of anionic, cationic, or zwitterionic organofluorine surfactants used in the formulations of thousands of products and consumer goods, including aqueous film-forming foams (AFFF) used to suppress aviation fires in training scenarios, non-stick cookware, fast-food wrappers, water-repellent fabrics, medical equipment. Because PFAS have been extensively used in a variety of AFFF products they can be found in soils from industrial and military installations. Current decontamination strategies of PFAS-burdened soils mainly consist of adsorption methods using adsorbents for fixation of PFAS in the ground. A second option is the utilization of a “pump and treat” process, cycling polluted soils through a washing plant leading to the concentration of the pollutants in the fine fraction. Only a subsequent, high-energy consuming pyrolysis process guarantees the total destruction of all fluorinated organic contaminants. Both approaches are cost-intensive and not intended for the direct decomposition of all PFAS contaminants. Hence, there is a great demand for innovative developments and chemical treatment technologies, dealing with new strategies of tackling the PFAS problem. Previously, mechanochemical treatment of polychlorinated organic compounds in soils showed an efficient dechlorination. Thus, we investigated mechanochemical treatment of PFAS contaminated soils with various additives in a ball mill and analyzed the PFAS defluorination with gas chromatography mass spectrometry (GCMS) and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively, as well es the fluoride mineralization by ion chromatography (IC) and fluorine K-edge X-ray absorption near-edge structure (XANES) spectroscopy.
Per- and polyfluoroalkyl substances (PFAS) are anionic, cationic and zwitterionic synthetic products, in which the hydrogen atoms on the carbon skeleton of at least one carbon atom have been completely replaced by fluorine atoms (see Figure 1) and which include more than 4730 compounds, depending on the definition. As a result of continuous and prolific use, mainly in aviation firefighting foams, thousands of industrial and military installations have been found to contain contaminated soil, groundwater and surface water. Furthermore, because of the continuous contamination through PFAS containing commercial products, effluents and sewage sludge from WWTPs have been shown to be an important source of PFAS discharge into the aquatic environment. In the last few years, legacy PFAS (≥C4) have been found in various environments, including soil, water and wastewater, and their environmental pathways have been partly described. To get a better
overview of the amount of “total PFAS,” sum parameter methods like total oxidizable precursor (TOP) assay and methods based on combustion ion chromatography (CIC) are in development. CIC results in data regarding the sum of absorbable organic fluorine (AOF) or extractable
organic fluorine (EOF), which can also quantify other organically bound fluorine compounds such as fluorinated pesticides and pharmaceutical. Additionally, for research purpose several spectroscopical methods like X-ray photoelectron spectroscopy (XPS), fluorine K-edge X-ray absorption near-edge structure (XANES) spectroscopy, particular induced gamma-ray emission (PIGE) spectroscopy and 19F nuclear magnetic resonance (NMR) spectroscopy are available. Therefore, an overview is given on various analytical techniques for PFAS in environmental samples and their application possibilities discussed for different kind of PFAS compounds
Geosynthetic materials are applied in measures for coastal protection. Weathering or any damage of constructions, as shown by a field study in Kaliningrad Oblast (Russia), could lead to the littering of the beach or the sea (marine littering) and the discharge of possibly harmful additives into the marine environment. The ageing behavior of a widely used geotextile made of polypropylene was studied by artificial accelerated ageing in water-filled autoclaves at temperatures of 30 to 80° C
and pressures of 10 to 50 bar. Tensile strength tests were used to evaluate the progress of ageing, concluding that temperature rather than pressure was the main factor influencing the ageing of geotextiles. Using a modified Arrhenius equation, it was possible to calculate the half-life for the loss of 50% of the strain, which corresponds to approximately 330 years.
Release of substances from joint grouts based on various binder types and their ecotoxic effects
(2022)
Background: The leaching of substances and the ecotoxic effects of eluates were studied for joint grouts that are based on various types of binders. Eight products, two of them containing either epoxy resin, polybutadiene or polyurethane binders, or modifed cement, were investigated using harmonized leaching tests for construction products in combination with ecotoxicity tests on algae, daphnia, luminescent bacteria, fish eggs and mutagenicity in accordance with CEN/TR 17105. In addition to basic parameters, such as pH, TOC, and inorganic components, organic substances in the eluates were analysed by gas and liquid chromatography in combination with mass spectrometry. Quantitative analyses in combination with ecotoxicity data on selected substances were used to deduce which substances cause the observed ecotoxic effects.
Results: Different patterns of ecotoxic effects were observed in joint grouts with different binder types. The most ecotoxic effects were observed in epoxy resin-based products, followed by polybutadiene-based products. Fewer ecotoxic effects were observed in polyurethane-based products and modifed cements. Some of these showed no ecotoxicity. Some of the substances in the eluates were identified and related to ecotoxic effects. 4-Tert-butylphenol and amines probably contributed to the ecotoxic effects of at least one of the epoxy resin-based renders, whereas cobalt is assumed to contribute to the toxic effect on algae of one of the polybutadiene-based products. However, only some of the leached substances could be identifed, and only some of the ecotoxic effects can be explained by the available information on the composition of eluates and known ecotoxic profiles of the identified substances.
Conclusions: Ecotoxicity tests on eluates from leaching tests indicate whether environmentally hazardous substances can be leached from construction products. Combined ecotoxicity tests and chemical analysis of eluates from EU-wide harmonized leaching tests for construction products can provide information on substances that cause these effects. This supports the identifcation and development of environmentally friendly construction products.
This study confirmed that ecotoxicity tests in accordance with CEN/TR 17105 are a tool well-suited to support the implementation of the European Commission’s zero pollution vision for 2050 and to reduce pollution to levels no longer considered harmful to health and natural ecosystems.
Per- and polyfluoroalkyl substances (PFAS) are a group of anionic, cationic and zwitterionic synthetic products, in which the hydrogen atoms on the carbon skeleton of at least one carbon atom have been completely replaced by fluorine atoms and which include more than 4730 compounds, depending on the definition. As a result of continuous and prolific use, mainly in aviation firefighting foams, thousands of industrial and military installations have been found to contain contaminated soil, groundwater and surface water. As a result of the perpetual use of PFAS containing products, effluents and sewage sludge from wastewater treatment plants (WWTPs) have been observed to be an important pathway for PFAS into the environment. In Germany, phosphorus and other nutrients from sewage sludge and wastewater should be recycled in WWTPs of cities with a large population. However, it is not clear if PFAS contamination from wastewater and sewage sludge end up in novel wastewater-based fertilizers. Normally, PFAS are analyzed using PFAS protocols typically with liquid chromatography tandem mass spectrometry (LC-MS/MS) quantification. To get a better overview of the amount of “total PFAS,” we applied sum parameter methods based on combustion ion chromatography (CIC) to screen the PFAS contaminations in various sewage sludge and wastewater-based fertilizers. Furthermore, current decontamination strategies of PFAS-burdened soils mainly consist of adsorption methods using adsorbents for fixation of PFAS in the ground. A second option is the utilization of a “pump and treat” process, cycling polluted soils through a washing plant leading to the concentration of the pollutants in the fine fraction. Only a subsequent, high-energy consuming pyrolysis process guarantees the total destruction of all fluorinated organic contaminants. Both approaches are cost-intensive and not intended for the direct decomposition of all PFAS contaminants. Hence, there is a great demand for innovative developments and chemical treatment technologies, dealing with new strategies of tackling the PFAS problem.
Weather conditions affect biocides on exposed outer surfaces on constructions. Contact with water causes hydrolysis and leaching of substances. Ultraviolet radiation may induce photolysis. As a result, a mixture of biocidal active substances and transformation products can be emitted into the environment. In a semi-field study, leaching of the biocidal active substances terbutryn, diuron, octylisothiazolinone, carbendazim, and selected transformation products was observed for two paints containing either a white or a red pigment. Painted test panels were exposed to natural weathering for about 1.5 years. Runoff samples were analyzed during the course of the experiment.
At the end of the study, residues of biocidal active substances and transformation products were determined in sections of the test panels. Emissions of substances were mainly observed during the first few months of the experiments. Increased emissions of transformation products were observed during periods of increased global radiation and subsequent periods with relatively high amounts of driving rain. Different patterns of transformation products were observed, especially for terbutryn, both for paints containing different pigments and in experiments that were started in different periods of the year, as well as during different periods of the experiments.
Industrial-scale mechanical recycling of plastics has been established for years, but has technical and economic limits. Chemical recycling processes lead back to monomers or to the raw materials, so that in the end new goods can be produced for all areas of application of plastics. The variety of chemical recycling processes is large. The capacities of the plants are still low today. The profitability of the plants is strongly influenced by the price of oil; the profitability limit is currently between 50 and 60 US $ per barrel.
Aim. The European biocidal products regulation requires environmental risk assessments for biocidal products under service conditions. This is only possible, if processes that lead to biocide emissions into the environment are understood and can be reasonably predicted.
Actual emissions due to leaching result from different processes that are affected by material properties and environmental conditions. Transformation of biocides can affect emissions considerably.
Leaching and possible transformation of the film preservatives carbendazim, diuron, OIT and terbutryn in paints was observed under laboratory and field conditons in order to investigate the influence of different factors, e.g. water contact and radiation on biocide emissions. The paints contained either white titanium dioxide or a red iron oxide pigment to check whether pigments affect leaching processes.
Methods. Test specimens of a water-based styrene acrylic dispersion paint on glass were exposed to UVA-radiation in a UV weathering device and/or exposed to water contact by immersion events on the basis of the European standard EN 16105. Plywood panels were coated and exposed to natural weather conditions in a semi-field experiment. Concentrations of biocides and transformation products were analysed in leachates from laboratory tests, runoff samples and remaining coatings.
Results. The impact of weathering conditions on transformation processes differs for the investigated active substances. Water contact, radiation as well as pigments in the paints determine the pattern and amount of transformation products on coatings, leachates and runoff water. Observations from laboratory and field experiments were compared. It proved that results from laboratory tests support understanding of data from field experiments.
Detailed knowledge on the fate of active substances under environmental conditions supports manufacturers to develop safe applications of film preservatives and authorities to evaluate its environmental impact.
The environmental impact assessment of materials is usually based on laboratory tests, mostly in combination with models describing the longterm fate of the substances of interest in the targeted environmental compartment. Thus, laboratory tests are the fundamental link to achieve appropriate assessment conclusions which makes it essential to generate consistent results. This just as applies to the leaching of cementitious materials. In Europe, the leaching behavior of monolithic building materials is tested in the Dynamic Surface Leaching Test following the specification CEN/TS 16637–2. An interlaboratory comparison on European level regarding this technical specification showed relatively high intra- and interlaboratory variations for the tested materials (monolithic copper slag and cement stabilized coal fly ash). Therefore the German Committee for Structural Concrete (DAfStb) framed a guideline to specify additional testing conditions for cementitious materials. To assess the possible improvement by this guidelines measures, a round robin test with 11 participants from Germany and the Netherlands was conducted. This work aims to provide insight into the factors to be considered in the testing of alkaline materials, including sample preparation, and highlights crucial procedures and their manifestation in the results. All evaluated parameters showed improved results compared to the earlier round robin test. The relative standard deviations for repeatability (RSDr) and reproducibility (RSDR) of the elements calcium, barium, antimony, chromium, molybdenum and vanadium, which are the parameters evaluated in both round robin tests, were RSDr = 4%, 4%, 2%, 5%, 5%, and 5% respectively (4% in average) for this work, in comparison to the European round robin test with an average RSDr of 29% (17%, 17%, 20%, 40%, 36%, and 42%). The RSDR improved from 41% (30%, 36%, 29%, 57%, 40%, and 56%) to 14% (12%, 8%, 6%, 28%, 15%, and 12%). CO2 ingress during testing and the inaccuracy of eluate analytics for concentrations close to the determination limits were identified as the main sources of error.
Per- and polyfluoroalkyl substances (PFAS) are a large group of organofluorine surfactants used in the formulations of thousands of consumer goods, including aqueous film-forming foams (AFFF) used to suppress aviation fires in training scenarios, non-stick cookware, fast-food wrappers, water-repellent fabrics, medical equipment, and plastic and leather products. As a result of the perpetual use of PFAS containing products, effluents and sewage sludge from wastewater treatment plants (WWTPs) have been observed to be an important pathway for PFAS into the environment. In Germany, phosphorus and other nutrients from sewage sludge and wastewater should be recycled in WWTPs of cities with a large population. However, it is not clear if PFAS contamination from wastewater and sewage sludge end up in novel wastewater-based fertilizers. Normally, PFAS are analyzed using PFAS protocols typically with time-consuming extraction steps and LC-MS-MS quantification. However, for screening of PFAS contaminations in sewage sludge or wastewater-based fertilizers also passive sampler based on the Diffusive Gradients in Thin-films (DGT) technique can be used for the PFAS extraction. Afterwards, combustion ion chromatography (CIC) can be applied to analyse the “total” amount of PFAS on the passive sampler. Here, we show results from the DGT method in comparison to those of the extractable organic fluorine (EOF) method for a variety of wastewater-based fertilizers. Additionally, we analysed the adsorption of PFAS on the weak anion exchanger (WAX) based DGT passive sampler binding layer by infrared and fluorine K-edge X-ray adsorption near-edge structure (XANES) spectroscopy.
Per- and polyfluoroalkyl substances (PFAS) have emerged over the course of the last twenty years as a global pollution issue. Altogether, there are currently more than 4700 known but only partly characterized fluorinated compounds identified by the Organization for Economic Cooperation and Development (OECD), as shown by a recently published classification proposal.
The ongoing production of new, yet unrestricted PFAS alternatives has become a major challenge for environmental routine analytics, since the state-of-the-art method LC-MS/MS relies on structural information and availability of isotope standards of the targeted compound. First reported by Miyake et al., fluorine sum parameters like adsorbable organic fluorine (AOF), extractable organic fluorine (EOF) and total fluorine (TF) can be applied to survey and detect the presence of large amounts of unidentified organofluorine compounds in environmental matrices. Today fluorine sum parameters have been established as a useful supplement to classic target-analytical approaches of PFAS and were implemented for the first time as a sum value “PFAS-total” in the recently revised Drinking Water Directive (2020/2184) by the European Commission.
In contrast, X-ray absorption near-edge structure (XANES) spectroscopy has been widely applied to identify low concentration of element-specific contamination without pre-treatment in environmental samples in the past. The XANES approach enables a penetration depth of approx. 1 µm (at fluorine K-edge energy; depending on the matrix) which is significantly deeper than for X-ray photoelectron spectroscopy (XPS; penetration depth approx. 10 nm). Furthermore, the method is fast, non-destructive and only simple preparation of the samples is required.
In our work, we combined both F-XANES spectroscopy and combustion ion chromatography (CIC) in order to present a new analytical perspective on the investigation of PFAS in environmental media and material samples.
The main obstacle to bottom ash (BA) being used as a recycling aggregate is the content of salts and potential toxic elements (PTEs), concentrated in a layer that coats BA particles. This work presents a dry treatment for the removal of salts and PTEs from BA particles. Two pilotscale abrasion units (with/without the removal of the fine particles) were fed with different BA samples. The performance of the abrasion tests was assessed through the analyses of particle size and moisture, and that of the column leaching tests at solid-to-liquid ratios between 0.3 and 4. The results were: the particle-size distribution of the treated materials was homogeneous (25 wt % had dimensions <6.3 mm) and their moisture halved, as well as the electrical conductivity of the leachates. A significant decrease was observed in the leachates of the treated BA for sulphates (44%),
chlorides (26%), and PTEs (53% Cr, 60% Cu and 8% Mo). The statistical analysis revealed good correlations between chloride and sulphate concentrations in the leachates with Ba, Cu, Mo, and Sr, illustrating the consistent behavior of the major and minor components of the layer surrounding BA particles. In conclusion, the tested process could be considered as promising for the improvement of BA valorization.
Here, we describe an optimized fast and simple extraction method for the determination of per- and polyfluorinated alkyl substances (PFASs) in soils utilizing high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR–CS–GFMAS). To omit the bias of the solid phase extraction (SPE) step commonly used during the analysis of extractable organically bound fluorine (EOF) we optimized a fast and simple SPE-free extraction method. The developed extraction method consists of a liquid-solid extraction using acidified methanol without any additional SPE. Four extraction steps were representative to determine a high proportion of the EOF (>80% of eight extractions). Comparison of the optimized method with and without an additional SPE clean-up step revealed a drastic underestimation of EOF concentrations using SPE. Differences of up to 94% were observed which were not explainable by coextracted inorganic fluoride. Therefore, not only a more accurate but also a more economic as well as ecologic method (bypassing of unnecessary SPE) was developed. The procedural limit of quantification (LOQ) of the developed method was 10.30 μg/kg which was sufficient for quantifying EOF concentrations in all tested samples. For future PFAS monitoring and potential regulative decisions the herein presented optimized extraction method can offer a valuable contribution.
Throughout their life cycles—from production, usage, through to disposal—materials and products interact with the environment (water, soil, and air). At the same time, they are exposed to environmental influences and, through their emissions, have an impact on the environment, people, and health. Accelerated experimental testing processes can be used to predict the long-term environmental consequences of innovative products before these actually enter the environment.
We are living in a material world. Building materials, geosynthetics, wooden toys, soil, nanomaterials, composites, wastes and more are research subjects examined by the authors of this book. The interactions of materials with the environment are manifold. Therefore, it is important to assess the environmental impact of these interactions. Some answers to how this task can be achieved are given in this Special Issue.
The most massive design on the Baltic shore used geosynthetic materials, the landslide protection construction in Svetlogorsk (1300 m long, 90,000 m2 area, South-Eastern Baltic, Kaliningrad Oblast, Russian Federation) comprises the geotextile and the erosion control geomat coating the open-air cliff slopes. Due to changes in elastic properties during long-term use in the open air, as well as due to its huge size, this structure can become a non-negligible source of microplastic pollution in the Baltic Sea. Weather conditions affected the functioning of the structure, so it was assessed that geosynthetic materials used in this outdoor (open-air) operation in coastal protection structures degraded over time. Samples taken at points with different ambient conditions (groundwater outlet; arid places; exposure to the direct sun; grass cover; under landslide) were tested on crystallinity and strain at break. Tests showed a 39–85% loss of elasticity of the polymer filaments after 3 years of use under natural conditions. Specimens exposed to sunlight are less elastic and more prone to fail, but not as much as samples taken from shaded areas in the grass and under the landslide, which were the most brittle.
Half of global material consumption involves mineral material. The circularity is still low so that the enhanced use of secondary building material is required to close loops. Three different secondary building materials are discussed based on exemplary research results: construction and demolition waste (C&D waste), soil-like material, and incineration bottom ash (IBA). Focus was placed on the environmental compatibility of the materials examined mainly by standardized leaching tests. C&D waste was investigated after a wet treatment using a jigging machine, and soil-like material and IBA were characterized with respect to their material composition. Their environmental compatibilities in particular were studied using standard leaching tests (batch tests and column tests).
It was concluded that soil-like material can mostly be utilized even when the precautionary limit values set are exceeded by a factor of less than two. For C&D waste, the fine fraction below 2 mm and the content of brick material is problematic. IBA fulfills quality level “HMVA-2” following German regulations. Improved levels of utilization might be achievable with better treatment technologies.
For the first time, µ-X-ray fluorescence (µ-XRF) mapping combined with fluorine K-edge µ-X-ray absorption near-edge structure (µ-XANES) spectroscopy was applied to depict per- and polyfluoroalkyl substances (PFAS) contamination and inorganic fluoride in samples concentrations down to 100 µg/kg fluoride. To demonstrate the matrix tolerance of the method, several PFAS contaminated soil and sludge samples as well as selected consumer product samples (textiles, food contact paper and permanent baking sheet) were investigated. µ-XRF mapping allows for a unique element-specific visualisation at the sample surface and enables localisation of fluorine containing compounds to a depth of 1 µm. Manually selected fluorine rich spots were subsequently analysed via fluorine K-edge µ-XANES spectroscopy. To support spectral interpretation with respect to inorganic and organic chemical distribution and compound class determination, linear combination (LC) fitting was applied to all recorded µ-XANES spectra. Complementarily, solvent extracts of all samples were target-analysed via LC-MS/MS spectrometry. The detected PFAS sum values range from 20 to 1136 µg/kg dry weight (dw). All environmentally exposed samples revealed higher concentration of PFAS with a chain length >C8 (e.g. 580 µg/kg dw PFOS for Soil1), whereas the consumer product samples showed a more uniform distribution with regard to chain lengths from C4 to C8. Independent from quantified PFAS amounts via target analysis, µ-XRF mapping combined with µ-XANES spectroscopy was successfully applied to detect both point-specific concentration maxima and evenly distributed surface coatings of fluorinated organic contaminants in the corresponding samples.
The chemical state of antimony and vanadium species in municipal solid waste incineration bottom ash
(2023)
Due to the large quantity as residual mineral waste, municipal solid waste incineration - bottom ash (MSWI-BA) is an interesting secondary raw material that can be utilized for road construction. However, leaching of chloride, sulfate and potentially hazardous heavy metals from MSWSI-BA into the environment may cause problems in utilization of it in civil engineering. In a previous study, we performed a long-term leaching test of MSWI-BA in a lysimeter for almost six years to investigate the efficiency of the treatment process on the release of hazardous substances. While concentrations of chloride, sulfate and the majority of the heavy metals started to decrease rapidly with progressive liquid-to-solid ratio (L/S), the ecotoxic hazardous elements antimony (Sb) and vanadium (V) behaved differently. To unravel these unusual release behaviors and the oxyanion-formation of Sb and V we will apply HERFD-XANES spectroscopy to analyze their chemical state.