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- Biotic weathering (2)
- Leaching (2)
- Passive sampling (2)
- Pesticides (2)
- ASE (1)
- Ageing (1)
- Albite (1)
- Analytical methods (1)
- Artificial turf (1)
- Artificial weathering (1)
Organisationseinheit der BAM
Im Rahmen eines ZIM-geförderten Projektes wurde eine nass-mechanische Aufbereitung von Hausmüllverbrennungsasche (HMVA) hinsichtlich der Mengen und der Qualitäten generierter Fraktionen optimiert. Dabei standen besonders die Qualitäten der mineralischen Fraktionen, die mengenmäßig den größten Anteil darstellen, im Vordergrund, da sie für einen möglichen Einsatz als Baustoff nutzbar gemacht werden sollen. Insbesondere die Chlorid- und Sulfatgehalte sollten dafür reduziert werden. Durch die BAM wurde im Projekt u. a. die Freisetzung von umweltrelevanten Stoffen in den mineralischen Fraktionen untersucht. Dafür wurden Schütteleluate als Übereinstimmungstest und Eluate aus Lysimeterversuchen im Labormaßstab zur Bewertung des Langzeitverhaltens auf ihre Inhaltsstoffe analysiert.
Sub-aerial biofilms (SAB) are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterized by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonization of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872) and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1–6 mm) were packed into flow-through columns and incubated with 0.1% glucose and 10 μM thiamine-hydrochloride (90 μL min−1) to compare weathering with and without biofilms. Dissolution of the minerals was followed by: (i) analysing the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii) by studying polished sections of the incubated mineral fragments/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favored a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analyzed.
Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Empore-TM styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d-1 and time-weighted average (TWA) concentrations from 0.05 to 2.11 µg/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides.
Column tests are a common tool to investigate the leaching behavior of contaminated soil and waste materials. In contrast to inorganic analytes, fewer studies with organic contaminants are available based on column tests. This paper is aimed at the question if soil materials contaminated with organic pollutants can be reliably investigated by column tests. Soils contaminated with TPH (total petrol hydrocarbons), PFC (perfluorinated surfactants) and the biocide tebuconazole were used for column percolation tests. Differences in the leaching behavior are mainly driven by partitioning behavior between organic carbon and water, which can be estimated from log KOW values and size and shape of molecules. PFC show higher release (10–50% for individual compounds) than pesticides (3.7–5.3%) and TPH (< 1%) at liquid to solid ratio of 4 l/kg. All eluate concentrations are low with maximum concentrations of 50 µg/l for PFC and 1–2 mg/l for pesticides and TPH. Despite this, the observed standard deviations are quite small suggesting good repeatability. In general the observed concentration trends are similar to that from lysimeter studies found in the literature and thus, it can be concluded that laboratory column experiments are a reliable tool for organic compounds with various physico-chemical properties.
Background and aims
Olive mill wastewater (OMW) generated in Mediterranean countries is partly disposed of on soil. Its underlying fate mechanisms and influences on plant growth are still largely unknown. Our goal was to understand OMW organic matter (OMW-OM) degradation in soil and its phytotoxic effects. We hypothesized that OMW phytotoxicity decreased with degradation of its phenolic components.
Methods
In a 60 day incubation study, we monitored soil respiration, extractable total phenolic content (TPC) and carbon isotope ratio (δ13C) of OMW treated Israeli soil. The soil was extracted using accelerated solvent extraction (ASE) and its extracts were exemplarily analyzed for four phenolic substances by LC/MS. Phytotoxicity of soil and soil extracts were tested using a Lepidium sativum seed germination bioassay.
Results
Soil respiration was 2.5 times higher for OMW treated soil with two respiration maxima and indicated a degradation of up to 27 % of the added OMW-OM. Four phases of OMW-OM degradation were identified: (i) degradation of easily degradable OMW-OM and transformation of phenolic compounds, (ii) intermediate suppression of phytotoxicity, (iii) degradation of phytotoxic phenolic compounds and (iv) significant physical immobilization of phytotoxic compounds.
Conclusion
Environmental conditions during and after OMW disposal on soil ought to favor fast degradation of OMW-OM, minimizing their physical immobilization and phytotoxic effects.
A laboratory biofilm consisting of the phototrophic cyanobacterium Nostoc punctiforme ATCC 29133 and the rock-inhabiting ascomycete Knufia petricola CBS 726.95 was tested for its mineral weathering potential. Minerals with different grain sizes and mineralogy were incubated with and without biofilm in batch and in flow-through column experiments. After incubation, the mineral dissolution was quantified analysing (i) leachate chemistry via ICP-OES/MS (inductively coupled plasma optical emission spectrometry/mass spectrometry) and (ii) the residual grains as thin polished sections via SEM/TEM-EDX (scanning electron microscopy/transmission electron microscopy-energy dispersive X-ray spectrometry). Mineral dissolution was enhanced in biotic experiments as compared to abiotic ones, for both batch culture and flow-through approaches. Analyses of thin polished sections confirmed the leaching of these elements near the surface of the mineral grains. These results clearly indicate a biotic effect on the weathering of minerals produced by the laboratory biofilm.
In Deutschland fallen aktuell über 5 Mio. Tonnen Hausmüllverbrennungsaschen (HMVA) pro Jahr an. Aus diesen werden nur ca. 8 % Metalle (davon ca. 1 % NE-Metalle) zurückgewonnen. Zur Beurteilung des Wertstoffpotentials werden die HMVA nach standardisierten Vorschriften beprobt, für die Analytik vorbehandelt/vorbereitet/aufgearbeitet und auf ihre Inhaltsstoffe analysiert. Im nachfolgenden Beitrag wird der Schwerpunkt auf die Probenvorbehandlung und -vorbereitung gelegt, wobei der Merkmalstransfer von der Ausgangs-(Feld-)Probe über die Laborprobe und die Prüfprobe bis zur Mess-(Analysen-) Probe am Beispiel von NE-Metallen einer nassaufbereiteten HMVA untersucht wurde. Die Ergebnisse wurden mit Hilfe statistischer Methoden bewertet. Die Ergebnisse zeigen, dass die Verteilung der NE-Metalle in den einzelnen Schritten der Probenbehandlung elementspezifisch ist. Bei Blei ist ein Erhalt der Merkmalsverteilung über alle Behandlungsschritte erkennbar. Bei Kupfer nehmen die Konzentrationen in den aufeinander folgenden Behandlungsschritten deutlich ab. Die Ursache könnte das in der Feinfraktion enthaltene metallische Kupfer mit seinen spezifischen Eigenschaften sein. -------------------------------------------------------------------------------------------------------------------------------------------
More than 5 billion tons of municipal solid waste incineration bottom ashes (MSWI BA) are generated by incineration per year in Germany. Currently only 8 % of metals (of these 1 % are non-ferrous metals) are recovered from MSWI BA. For characterization of recovery potential, MSWI BA samples have to be taken, pre-treated and analyzed according to standardized methods. This manuscript focuses on sample pre-treatment and preparation of a MSWI BA sample aiming to investigate the characteristics transfer over the process of sub-sampling from the original (field) sample to the laboratory sample, test sample until the analytical sample. All results have been evaluated with statistical methods. The results show that influence of each single pre-treatment and preparation step on metal content differs for the individual metals. For lead a conservation of characteristics distribution can be observed, while for copper a continuous decline of solid concentration is observed over all preparation steps. One possible reason may be the fact that copper is mainly contained in the fine fraction as metallic copper with specific properties.
The European Construction Products Regulation allows Member States to adopt rules for evaluating the environmental impact of their buildings. The aim of the project was to develop recommendations for a test battery for the ecotoxicological assessment of the environmental impact of construction products for outdoor use and contribute to the European harmonization of test methods. From a shortlist of 39 products 20 products were included in the ecotoxicological testing program. Monolithic and plate-like construction products were eluted in the Dynamic Surface Leaching test (DSLT) in accordance with CEN/TS 16637-2, granular products were eluted in a one stage batch test in accordance with DIN EN 12457-1. The eluates were examined in four aquatic toxicity tests (algae, daphnia, luminescent bacteria, fish eggs), a genotoxicity test (umu test) and in the respirometer test (OECD 301 F). Here, low to very high ecotoxicity was observed (up to a dilution factor of 1536). Six out of 8 eluates, whose TOC exceeded 10 mg L⁻1 showed a good biodegradability above 75%. The intra-laboratory repeatability of the Lowest Ineffective Dilution (LID) usually was within ±1 dilution steps (ecotoxicity tests) and ±2 dilution steps (leaching and ecotoxicity tests). This is acceptable, when considering that the overall variability of sample preparation, leaching test, and bioassays add up. The conclusions lead to practical recommendations for a suitable combination of leaching and ecotoxicity tests.
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.
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.