TY - JOUR A1 - Krüger, Oliver A1 - Adam, Christian A1 - Hobohm, J. A1 - Basu, S. A1 - Kuchta, K. A1 - van Wasen, Sebastian T1 - Recycling oriented comparison of mercury distribution in new and spent fluorescent lamps and their potential risk N2 - This study compares the mercury distribution in the vapor phase, the phosphor powder and the glass matrix of new and spent fluorescent lamps. The spent fluorescent lamps were obtained at the collection yards of a public waste management company in Hamburg, Germany. An innovative systematic sampling method is utilized to collect six spent and eight corresponding new, off-the-shelf fluorescent lamp samples. The efficiency of several acid digestion methods for the determination of the elemental composition was studied and elemental mass fractions of K, Na, Y, Ca, Ba, Eu, Al, Pb, Mg, Hg, and P were measured. The study also finds aqua regia to be the best reagent for acid digestion. However, no significant difference in mercury distribution was found in the different phases of the new and spent fluorescent lamps. KW - Mercury KW - Rare earth elements KW - Hg distribution KW - Fluorescence lamps PY - 2017 DO - https://doi.org/10.1016/j.chemosphere.2016.11.104 SN - 0045-6535 SN - 1879-1298 VL - 169 SP - 618 EP - 626 PB - Elsevier AN - OPUS4-38481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peplinski, Burkhard A1 - Adam, Christian A1 - Adamczyk, Burkart A1 - Müller, Ralf A1 - Michaelis, Matthias A1 - Krahl, T. A1 - Emmerling, Franziska T1 - Nanocrystalline and stacking-disordered beta-cristobalite AlPO4: the now deciphered main constituent of a municipal sewage sludge ash from a full-scale incineration facility N2 - For the first time evidence is provided that a nanocrystalline and stacking-disordered, chemically stabilized β-cristobalite form of AlPO4 occurs in a sewage sludge ash (SSA). This proof is based on a combined X-ray powder diffraction and X-ray fluorescence investigation of an SSA produced at a large-scale fluidized bed incineration facility serving a catching area with a population of 2 million. The structural and chemical characterization was carried out on 'as received' SSA samples as well as on solid residues remaining after leaching this SSA in sodium hydroxide solution. Thus, it was ascertained that the observed nanocrystalline and stacking-disordered cristobalite-like component belongs to the aluminum phosphate component of this SSA, rather than to its silicon dioxide component. In addition, a direct proof is presented that the chemically stabilized β-cristobalite form of AlPO4 does crystallize from X-ray amorphous precursors under conditions that mimic the huge heating rate and short retention time (just seconds at T ≈ 850°C), typical for fluidized bed incinerators. KW - Aluminum phosphate KW - Chemical stabilization of high-temperature forms KW - Cristobalite form KW - Stacking disorder KW - Incinerator ash KW - Sewage sludge ash PY - 2015 DO - https://doi.org/10.1017/S0885715614001213 SN - 0885-7156 VL - 30 IS - Supplement S 1 SP - S31 EP - S35 PB - JCPDS CY - Swarthmore, Pa. AN - OPUS4-33435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schraut, Katharina A1 - Adamczyk, Burkart A1 - Adam, Christian A1 - Stephan, D. A1 - Meng, Birgit A1 - Simon, Sebastian A1 - von Werder, Julia T1 - Synthesis and characterisation of alites from reduced basic oxygen furnace slags N2 - Basic oxygen furnace slags (BOFS) are by-products of the steelmaking process. Several researchers have studied the production of Portland cement clinker and metallic iron from BOFS via a reductive treatment. In this study, we applied a carbothermal reduction of BOFS in a technical-scale electric arc furnace and characterised the clinker-like products. Those clinker-like non-metallic products (NMPs) had a chemical and mineralogical composition comparable to clinker for ordinary Portland cement (OPC) and contained large elongated alite crystals as major component. The pure NMPs reacted more slowly and achieved a lower degree of hydration compared with commercial OPC. If the reactivity of the products can be further increased by employing specific adaptations, it can be used as a full clinker substitute for OPC. Nevertheless, it is also an option to use the material without further modifications as a cement component or concrete addition, which contributes to the strength development in both cases. KW - BOFS KW - Hydration products KW - Thermal analysis KW - X-ray diffraction PY - 2021 DO - https://doi.org/10.1016/j.cemconres.2021.106518 SN - 0008-8846 VL - 147 SP - 6518 PB - Elsevier Ltd. AN - OPUS4-52939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Raniro, H.R. A1 - Teles, A.P. A1 - Pavinato, P.S. A1 - Adam, Christian T1 - Phosphorus solubility and dynamics in a tropical soil under sources derived from wastewater and sewage sludge N2 - Conventional phosphate fertilizers are usually highly water-soluble and rapidly solubilize when moistened by the soil solution. However, if this solubilization is not in alignment with plants demand, P can react with the soil colloidal phase, becoming less available over time. This is more pronounced in acidic, oxidic tropical soils, with high P adsorption capacity, reducing the efficiency of P fertilization. Furthermore, these fertilizers are derived from phosphate rock, a non-renewable resource, generating an environmental impact. To assess these concerns, waste-recycled P sources (struvite, hazenite and AshDec®) were studied for their potential of reducing P Fixation by the soil and improving the agronomic efficiency of the P fertilization. In our work, we compared the solubilization dynamics of struvite, hazenite, AshDec® to triple superphosphate (TSP) in a sandy clay loam Ferralsol, as well as their effect on solution pH and on soil P pools (labile, moderately-labile and non-labile) via an incubation experiment. Leaching columns containing 50 g of soil with surface application of 100 mg per column (mg col􀀀 1) of P from each selected fertilizer and one control (nil-P) were evaluated for 60 days. Daily leachate samples from the column were analyzed for P content and pH. Soil was stratified in the end and submitted to P fractionation. All results were analyzed considering p < 0.05. Our findings showed that TSP and struvite promoted an acid P release reaction (reaching pHs of 4.3 and 5.5 respectively), while AshDec® and hazenite reaction was alkaline (reaching pHs of 8.4 and 8.5 respectively). Furthermore, TSP promoted the highest P release among all sources in 60 days (52.8 mg col􀀀 1) and showed rapid release dynamic in the beginning, while struvite and hazenite showed late release dynamics and lower total leached P (29.7 and 15.5 mg col􀀀 1 P respectively). In contrast, no P-release was detected in the leachate of the AshDec® over the whole trial period. Struvite promoted the highest soil labile P concentration (7938 mg kg􀀀 1), followed by hazenite (5877 mg kg􀀀 1) and AshDec® (4468 mg kg􀀀 1), all higher than TSP (3821 mg kg􀀀 1), while AshDec® showed high moderately-labile P (9214 mg kg􀀀 1), reaffirming its delayed release potential. KW - Phosphate dynamics KW - Struvite KW - Wastewater KW - Sewage sludge ash KW - CaNaPO4 KW - P speciation PY - 2022 DO - https://doi.org/10.1016/j.jenvman.2021.113984 VL - 302 IS - Part A SP - 113984 PB - Elsevier Ltd. AN - OPUS4-53600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adam, Christian A1 - Kley, Gerd A1 - Simon, Franz-Georg T1 - Thermal treatment of municipal sewage sludge aiming at marketable P-fertilisers N2 - Municipal sewage sludge is a carrier of nutrients – most important phosphorus (P) – but also contains organic pollutants and heavy metals. A two steps thermal treatment is suggested based on 1. mono-incineration of sewage sludge under destruction of organic pollutants and 2. thermochemical treatment of the resulting ashes to remove heavy metals and increase P-bioavailability. The targeted products are marketable P-fertilisers. The thermochemical treatment was investigated in a gas tight lab-scale rotary furnace. Seven sewage sludge ashes of different origin and composition and one residue from gasification of sewage sludge were mixed with a chlorine donor (e.g. MgCl2) and thermochemically treated under systematic variation of operational parameters. The distributions of the heavy metals between solid and gas phase were determined. The heavy metals concentrations of the treated ashes met the legislative limits in most cases. The products from thermochemical treatment are suited raw materials for P-fertiliser production. Relevant process parameters such as temperature, type and concentration of Cl-donor and retention time were optimised for the thermochemical treatment step. KW - Sewage sludge KW - Mono-incineration KW - Ash treatment KW - Thermochemical treatment KW - Phosphorus-fertiliser PY - 2007 SN - 1345-9678 SN - 1347-5320 VL - 48 IS - 12 SP - 3056 EP - 3061 PB - Japan Institute of Metals CY - Sendai AN - OPUS4-16647 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herzel, Hannes A1 - Krüger, Oliver A1 - Hermann, L. A1 - Adam, Christian T1 - Sewage sludge ash - A promising secondary phosphorus source for fertilizer production N2 - Sewage sludge incineration is extensively practiced in some European countries such as the Netherlands, Switzerland, Austria and Germany. A survey of German sewage sludge ash showed that the recovery potential is high, approx. 19,000 t of phosphorus per year. However, the survey also discovered that the bioavailability of phosphorus in the sewage sludge ash is poor and that more than half of the ashes cannot be used as fertilizers due to high heavy metal content. A new thermochemical process for sewage sludge ash treatment was developed that transforms the ash into marketable fertilizer products. Sewage sludge ash was thermochemically treated with sodium and potassium additives under reducing conditions, whereby the phosphate-bearing mineral phases were transformed into plant available phosphates. High P-bioavailability was achieved with a molar Na/P ratio > 1.75 in the starting materials. Sodium sulfate, carbonate and hydroxide performed comparably as additives for this calcination process. Potassium carbonate and -hydroxide have to be added in a molar K/P ratio > 2.5 to achieve comparable P-solubility. The findings of the laboratory scale investigations were confirmed by an industrial demonstration trial for an ash treatment with sodium sulfate. Simultaneously, the volatile transition metal arsenic (61% removal) as well as volatile heavy metals such as cadmium (80%), mercury (68%), lead (39%) and zinc (9%) were removed via the off-gas treatment system. The product of the demonstration trial is characterized by high bioavailability and a toxic trace element mass fraction below the limit values of the German fertilizer ordinance, thus fulfilling the quality parameters for a P-fertilizer. KW - Sewage sludge ash KW - Phosphorus recovery KW - Thermochemical treatment KW - Reducing conditions KW - Heavy metal evaporation KW - Bioavailability KW - Sodium sulfate PY - 2016 DO - https://doi.org/10.1016/j.scitotenv.2015.08.059 SN - 0048-9697 SN - 1879-1026 IS - 542 SP - 1136 EP - 1143 PB - Elsevier CY - Amsterdam AN - OPUS4-34165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adam, Christian A1 - Peplinski, Burkhard A1 - Michaelis, Matthias A1 - Kley, Gerd A1 - Simon, Franz-Georg T1 - Thermochemical treatment of sewage sludge ashes for phosphorus recovery N2 - Phosphorus (P) is an essential element for all living organisms and cannot be replaced. Municipal sewage sludge is a carrier of phosphorus, but also contains organic pollutants and heavy metals. A two-step thermal treatment is suggested, including mono-incineration of sewage sludge and subsequent thermochemical treatment of the ashes. Organic pollutants are completely destroyed by mono-incineration. The resulting sewage sludge ashes contain P, but also heavy metals. P in the ashes exhibits low bioavailability, a disadvantage in farming. Therefore, in a second thermochemical step, P is transferred into mineral phases available for plants, and heavy metals are removed as well. The thermochemical treatment was investigated in a laboratory-scale rotary furnace by treating seven different sewage sludge ashes under systematic variation of operational parameters. Heavy metal removal and the increase of the P-bioavailability were the focus of the investigation. The present experimental study shows that these objectives have been achieved with the proposed process. The P-bioavailability was significantly increased due to the formation of new mineral phases such as chlorapatite, farringtonite and stanfieldite during thermochemical treatment. KW - P-recovery KW - Sewage sludge ash KW - Thermochemical treatment KW - Mineral phases KW - X-ray diffraction PY - 2009 DO - https://doi.org/10.1016/j.wasman.2008.09.011 SN - 0956-053X VL - 29 IS - 3 SP - 1122 EP - 1128 PB - Pergamon Press CY - New York, NY AN - OPUS4-18605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ante, A. A1 - Trumpler, A. A1 - Niermann, S. A1 - Decker, Renate A1 - Hermann, L. A1 - Adam, Christian T1 - SUSAN - Sustainable and safe re-use of municipal sewage sludge for nutrient recovery KW - Sewage sludge KW - Phosphorus KW - Recycling KW - Thermochemical treatment KW - Heavy metal removal KW - Large scale consideration PY - 2010 SN - 0016-3651 VL - 151 IS - 13 SP - 78 EP - 84 PB - Oldenbourg-Industrieverl. CY - München AN - OPUS4-22097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hobohm, J. A1 - Kuchta, K. A1 - Krüger, Oliver A1 - van Wasen, Sebastian A1 - Adam, Christian T1 - Optimized elemental analysis of fluorescence lamp shredder waste N2 - Fluorescence lamps contain considerable amounts of rare earth elements (REE). Several recycling procedures for REE recovery from spent lamps have been established. However, despite their economic importance, the respective recycling is scarce so far, with an REE recovery rate of less than 1%. A reliable analysis of REE and other relevant metals like Yttrium is crucial for a thorough and complete recovery process. This applies both to the solid matter and aqueous phase, since most of the recycling processes include wet-chemical steps. We tested seven different reagent mixtures for microwave-assisted digestion of fluorescent lamp shredder, including hydrofluoric acid, perchloric acid, and hydrogen peroxide. We determined the concentrations of 25 of the most relevant rare earth and other trace elements (Al, P, Ti, V, Cr, Fe, Ni, Cu, Ga, Ge, As, Y, Ag, Cd, Sn, Sb, La, Ce, Eu, Gd, Tb, W, Au, Hg, and Pb) in the respective dilutions. Two independent digestions, one a mixture of perchlorid/nitric/hydrofluoric acid and the other aqua regia, showed the highest concentrations of 23 of these elements, excluding only Sn and Tb. The REE concentrations in the tested lamp shredder sample (stated in g/kg) were 10.2 (Y), 12.1 (La), 7.77 (Ce), 6.91 (Eu), 1.90 (Gd), and 4.11 (Tb). KW - Yttrium KW - Rare earth elements KW - Elemental analysis KW - Microwave-assisted digestion PY - 2016 DO - https://doi.org/10.1016/j.talanta.2015.09.068 SN - 0039-9140 VL - 147 SP - 615 EP - 620 PB - Elsevier CY - Amsterdam AN - OPUS4-34992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stemann, Jan A1 - Peplinski, Burkhard A1 - Adam, Christian T1 - Thermochemical treatment of sewage sludge ash with sodium salt additives for phosphorus fertilizer production - Analysis of underlying chemical reactions N2 - Stocks of high grade phosphate rock are becoming scarce, and there is growing concern about potentially harmful impurities in conventional phosphorus fertilizers. Sewage sludge ash is a promising secondary phosphorus source. However, to remove heavy metals and convert the phosphorus contained in sewage sludge ash into mineral phases available to plants, an after-treatment is required. Laboratory-scale calcination experiments of sewage sludge ash blended with sodium salts using dried sewage sludge as a reducing agent were carried out at 1000 °C. Thus, the Ca3(PO4)2 or whitlockite component of raw sewage sludge ash, which is not readily plant available, was converted to CaNaPO4 (buchwaldite). Consequently, nearly complete phosphorus solubility in ammonium citrate (a well-established indicator for plant availability) was achieved. Moreover, it was shown that Na2CO3 may be replaced by moderately priced Na2SO4. However, molar ratios of Na/P > 2 were required to achieve >80% phosphorus solubility. Such over-stoichiometric Na consumption is largely caused by side reactions with the SiO2 component of the sewage sludge ash – an explanation for which clear evidence is provided for the first time. KW - Phosphorus recovery KW - Plant availability KW - Solubility in ammonium citrate KW - Whitlockite-to-buchwaldite transformation PY - 2015 DO - https://doi.org/10.1016/j.wasman.2015.07.029 SN - 0956-053X VL - 45 SP - 385 EP - 390 PB - Pergamon Press CY - New York, NY AN - OPUS4-33876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adam, Christian A1 - Kley, Gerd A1 - Simon, Franz-Georg A1 - Lehmann, Annekatrin T1 - Recovery of nutrients from sewage sludge - Results of the European research-project SUSAN N2 - Municipal sewage sludge is a carrier of nutrients – most important phosphorus (P) – but also contains organic pollutants and heavy metals. A two steps thermal treatment based on 1. mono-incineration of sewage sludge under destruction of organic pollutants and 2. thermochemical treatment of the resulting ashes to remove heavy metals and increase P-bioavailability is suggested by the authors. The process aims at P-fertilisers production from sewage sludge. Seven sewage sludge ashes of different origin and composition and one residue from gasification of sewage sludge were thermochemically treated. The raw ashes were mixed with a chlorine donor (e.g. MgCl2) and thermally treated in a gas tight lab-scale rotary furnace. The distributions of the heavy metals between solid and gas phase were determined. The heavy metals concentrations of the treated ashes matched the legislative limits in most cases. The products from thermochemical treatment are suited raw materials for P-fertiliser production. Relevant process parameters such as temperature, type and concentration of Cl-donor and retention time were optimised for the thermochemical treatment step. KW - Phosphorus recovery KW - Sewage sludge ash KW - Thermochemical treatment KW - Fetiliser PY - 2008 DO - https://doi.org/10.2166/wpt.2008.001 SN - 1751-231X VL - 3 IS - 1 SP - 1 EP - 8 PB - IWA Publishing AN - OPUS4-17700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sichler, Theresa Constanze A1 - Adam, Christian A1 - Montag, D. A1 - Barjenbruch, M. T1 - Future nutrient recovery from sewage sludge regarding three different scenarios - German case study N2 - Agricultural sewage sludge utilization becomes less important in Germany. In 2017, new fertilizer and waste laws caused the agricultural sewage sludge utilization to collapse by more than a quarter. From 2029, German wastewater treatment plants (WWTPs) must recover phosphorus (P) from sewage sludge if it contains more than 2 wt % P. Agricultural utilization will be prohibited for large WWTPs >100,000 population equivalents (pe) from 2029 and >50,000 pe from 2032. In Germany, each federal state must annually report amounts and quality of agriculturally utilized sewage sludge which was 16% of the total disposal in 2019. The reports of 10 states were evaluated for 2016 and 2017 representing approx. 60% of the total agriculturally used sludge volume. In 2016, 60% of the WWTPs’ sludges exceeded the recovery limit of 2 wt % P which is 70% of the amount of sludge and 85% of the phosphorus load. Other nutrients are not affected by the recovery obligation. However, many P recovery processes recover other nutrients, too. Considering three different scenarios for future German sewage sludge disposal shows that 70–77% of the P load in sewage sludge will probably be recovered in the future. At the same time, this applies for about 0–16% nitrogen, 36–52% of calcium, 31–53% of potassium, and 40–52% of magnesium. However, these recovered nutrients loads can substitute only 1% or less of the commercial fertilizer demand except from phosphorus which is up to 43% of the demand. KW - Sewage sludge KW - Phosphorus recovery KW - Wastewater KW - Sewage sludge disposal PY - 2022 DO - https://doi.org/10.1016/j.jclepro.2021.130130 VL - 333 SP - 1 EP - 10 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-54186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vocks, M. A1 - Adam, Christian A1 - Lesjean, B. A1 - Gnirrs, R. A1 - Kraume, M. T1 - Enhanced post-denitrification without addition of an external carbon source in membrane bioreactors N2 - This study investigates a post-denitrification process without the addition of an external carbon source combined with an enhanced biological phosphorus removal (EBPR) in a membrane bioreactor (MBR). Three trial plants, with two different process configurations, were operated on two different sites, and a variety of accompanying batch tests were conducted. It was shown that even without dosing of an external carbon source, denitrification rates (DNR) much above endogenous rates could be obtained in post-denitrification systems. Furthermore, the anaerobic reactor located ahead of the process had a positive impact on the DNR. Given these surprising results, the project team decided to identify the carbon source used by the microorganisms in the post-denitrification process. Batch tests could demonstrate that lysis products do not play a major role as a C-source for post-denitrification. The following hypothesis was proposed to explain the observations: the glycogen, internally stored by the substrate accumulating bacteria, if anaerobic conditions are followed by aerobic conditions could act as carbon source for denitrification in post-denitrification system. First exploratory batch tests, where the glycogen evolution was monitored, corroborate this assumption. KW - Post-denitrification KW - EBPR KW - Glycogen KW - MBR KW - Metabolism KW - Internal substrate KW - Denitrification rate PY - 2005 DO - https://doi.org/10.1016/j.watres.2005.05.049 SN - 0043-1354 VL - 39 IS - 14 SP - 3360 EP - 3368 PB - Elsevier CY - Amsterdam AN - OPUS4-10760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adamczyk, Burkart A1 - Brenneis, Rudolf A1 - Adam, Christian A1 - Mudersbach, D. T1 - Recovery of chromium from AOD-converter slags N2 - Slags from the production of high-alloyed steel contain both chemically bound chromium (mainly as Cr2O3) in the mineral fraction and elemental chromium in the metallic remainders. Thermochemical post treatment of the slag in an electric arc furnace under reducing conditions enables the nearly complete recovery of the total amount of chromium in form of a metallic alloy. The best results were achieved by resistance melting (submerged electrodes) with addition of a reducing agent into the melt. The efficiencies of the reducing agents carbon, aluminium, silicon (as ferrosilicon) and silicon carbide were investigated and compared. As aluminium is the strongest reducing agent, it is less selective and reduces much more SiO2 than Cr2O3. While SiC shows only low reactivity because of its high thermal resistance, carbon and silicon had the highest reducing potentials: More than 97% of the chemically bound chromium can be recovered by application of these reducing agents. Due to the high temperature required for the reduction of the chromium compounds, the reduction of SiO2 as an undesired side reaction cannot be avoided. However, compared with mechanical procedures that are limited to the recovery of the metallic remainders, the total chromium recovery can be significantly increased by the described reductive melting procedure. KW - Arc furnace KW - By-product KW - Chromium recovery KW - High-alloyed steel KW - Reductive melting KW - Slag treatment KW - Slag KW - Thermochemical treatment PY - 2010 DO - https://doi.org/10.1002/srin.201000193 SN - 1611-3683 SN - 0177-4832 VL - 81 IS - 12 SP - 1078 EP - 1083 PB - Verl. Stahleisen CY - Düsseldorf AN - OPUS4-22898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Oliver A1 - Grabner, Angela A1 - Adam, Christian T1 - Complete survey of German sewage sludge ash N2 - The amount of sewage sludge produced worldwide is expected to further increase due to rising efforts in wastewater treatment. There is a growing concern against its direct use as fertilizer due to contamination of the sludge with heavy metals and organic pollutants. Incinerating the sludge degrades organic compounds almost completely and concentrates heavy metals and phosphorus. However, the sewage sludge ash (SSA) is almost completely disposed of and with it all resources are removed from the economic cycle. Comprehensive knowledge of the composition of SSA is crucial to assess the resource recovery potentials. We conducted a survey of all SSA emerging in Germany and determined the respective mass fractions of 57 elements over a period of one year. The median content of phosphorus was 7.9%, indicating an important recovery potential. Important trace elements were Zn (2.5 g/kg), Mn (1.3 g/kg), and Cu (0.9 g/kg). Mass fractions of technology metals such as V, Cr, Ga, Nb, and rare earths were comparatively low. Considering the possible use of SSA as secondary raw material for fertilizer production it should be noted that its Cd and U content (2.7 mg/kg and 4.9 mg/kg respectively) is significantly lower than that of rock phosphate based mineral fertilizers. PY - 2014 DO - https://doi.org/10.1021/es502766x SN - 0013-936X SN - 1520-5851 VL - 48 IS - 20 SP - 11811 EP - 11818 PB - ACS Publ. CY - Washington, DC AN - OPUS4-32646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gentzmann, Marie A1 - Paul, Andrea A1 - Serrano, Juan A1 - Adam, Christian T1 - Understanding scandium leaching from bauxite residues of different geological backgrounds using statistical design of experiments N2 - The leaching behavior of scandium (Sc) from bauxite residues can differ significantly when residues of different geological backgrounds are compared. The mineralogy of the source rock and the physicochemical environment during bauxitization affect the association of Sc in the bauxite i.e., how Sc is distributed amongst different mineral phases and whether it is incorporated in and/or adsorbed onto those phases. The Sc association in the bauxite is in turn crucial for the resulting Sc association in the bauxite residue. In this study systematic leaching experiments were performed on three different bauxite residues using a statistical design of experiments approach. The three bauxite residues compared originated from processing of lateritic and karstic bauxites from Germany, Hungary, and Russia. The recovery of Sc and Fe was determined by ICP-OES measurements. Mineralogical changes were analyzed by X-ray-diffraction and subsequent Rietveld refinement. The effects of various parameters including temperature, acid type, acid concentration, liquid-to-solid ratio and residence time were studied. A response surface model was calculated for the selected case of citric acid leaching of Hungarian bauxite residue. The investigations showed that the type of bauxite residue has a strong influence. The easily leachable fraction of Sc can vary considerably between the types, reaching ~20–25% in German Bauxite residue and ~50% in Russian bauxite residue. Mineralogical investigations revealed that a major part of this fraction was released from secondary phases such as cancrinite and katoite formed during Bayer processing of the bauxite. The effect of temperature on Sc and Fe recovery is strong especially when citric acid is used. Based on the exponential relationship between temperature and Fe-recovery it was found to be particularly important for the selectivity of Sc over Fe. Optimization of the model for a maximum Sc recovery combined with a minimum Fe recovery yielded results of ~28% Sc recovery at <2% Fe recovery at a temperature of 60 ◦C, a citric acid normality of 1.8, and a liquid-to-solid ratio of 16 ml/g. Our study has shown that detailed knowledge about the Sc association and distribution in bauxite and bauxite residue is key to an efficient and selective leaching of Sc from bauxite residues. KW - Bauxite residue KW - Scandium KW - Leaching KW - Design of experiments KW - Red mud PY - 2022 DO - https://doi.org/10.1016/j.gexplo.2022.107041 SN - 0375-6742 VL - 2022 IS - 240 SP - 1 EP - 13 PB - Elsevier Science CY - Amsterdam AN - OPUS4-55531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peplinski, Burkhard A1 - Adam, Christian A1 - Adamczyk, Burkart A1 - Müller, Ralf A1 - Schadrack, Reinhard A1 - Michaelis, Matthias A1 - Emmerling, Franziska A1 - Reuther, H. A1 - Menzel, Michael T1 - Evidence of formation of the tridymite form of AlPO4 in some municipal sewage sludge ashes N2 - Evidence is provided that the tridymite component observed in the X-ray diffraction patterns of some sewage sludge ashes (SSAs) should not be interpreted as the tridymite modification of SiO2 but as the tridymite form of AlPO4. This proof is based on a combined X-ray Powder Diffraction (XRD), X-ray fluorescence (XRF) and Mossbauer spectroscopy investigation of two SSAs produced at two fluidized bed incineration facilities, located in different municipalities and operated differently. The structural and chemical characterization was carried out on the 'as received' SSA samples as well as on the residues of these two SSAs pretreated by leaching in citric acid. In addition, direct proof is presented that the tridymite form of AlPO4 does crystallize from X-ray amorphous precursors under conditions that mimic the huge heating rate and short retention time (just seconds at T ≈ 850 °C) typical for fluidized bed incinerators. KW - Aluminium phosphate KW - Ash KW - Fly ash KW - Incinerator ash KW - Sewage sludge ash KW - Tridymite form PY - 2013 DO - https://doi.org/10.1017/S0885715613000869 SN - 0885-7156 VL - 28 IS - S2 SP - S425 EP - S435 PB - JCPDS CY - Swarthmore, Pa. AN - OPUS4-29703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Oliver A1 - Adam, Christian T1 - Recovery potential of German sewage sludge ash N2 - Incineration of sewage sludge is expected to increase in the future due to growing concerns about the direct use of sludge in agriculture. Sewage sludge is the pollutant sink of wastewater treatment and thus loaded with contaminants that might pose environmental hazards. Incineration degrades organic pollutants efficiently, but since the ash is currently mostly disposed of, all valuable component like phosphorus (P) and technologically relevant metals present in the sewage sludge ash (SSA) are removed from the economic cycle entirely. We conducted a complete survey of SSA from German mono-incineration facilities and determined the theoretical recovery potential of 57 elements. German SSA contains up to 19,000 t/a P which equals approximately 13% of phosphorus applied in the German agriculture in form of phosphate rock based mineral fertilizers. Thus, SSA is an important secondary resource of P. However, its P-solubility in ammonium citrate solution, an indicator for the bioavailability, is only about 26%. Treatment of SSA is recommended to enhance P bioavailability and remove heavy metals before it is applied as fertilizer. The recovery potential for technologically relevant metals is generally low, but some of these elements might be recovered efficiently in the course of P recovery exploiting synergies. KW - Sewage sludge ash KW - Recovery potential KW - Phosphorus KW - Critical raw materials KW - Bioavailability KW - Phosphorus recovery KW - Monitoring PY - 2015 DO - https://doi.org/10.1016/j.wasman.2015.01.025 SN - 0956-053X VL - 45 SP - 400 EP - 406 PB - Pergamon Press CY - New York, NY AN - OPUS4-34157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Severin, M. A1 - Breuer, J. A1 - Rex, M. A1 - Stemann, Jan A1 - Adam, Christian A1 - Van den Weghe, H. A1 - Kücke, M. T1 - Phosphate fertilizer value of heat treated sewage sludge ash N2 - This study focuses on the question whether heat treated sewage sludge ashes are more favourable as fertilizers than untreated sewage sludge ashes (USSA) and whether their fertilization effects are comparable with commercial triple superphosphate (TSP). In a pot experiment, maize was fertilized either with one of three heat treated and Na-, Ca- and Si-compounds amended sewage sludge ashes (two glown phosphates, steel mill slag + sewage sludge ash) or USSA or TSP as control. Fertilization with USSA did not increase the biomass yield and the P uptake of maize in comparison to the P0 treatment (7.25 resp. 8.35 g dry matter/pot). Fertilization with heat treated sewage sludge ashes and TSP resulted in significantly higher yields and plant P uptakes which are on average eight times higher than treatment with USSA and P0 control. Biomass yields and P uptake of maize after fertilization with heat treated sewage sludge ashes are not significantly different from those after TSP fertilization. The main P compound in USSA is Ca3(PO4)2. By heat treatment and amendment with different sodium, calcium, sulphur and silicon containing additives or steel mill converter slag, Ca3(PO4)2 is converted to Ca- and Na-silico-phosphates, which have a higher water solubility than Ca3(PO4)2. This increased solubility is responsible for the high plant availability of this phosphates. KW - P recycling KW - Sustainability KW - P solubility PY - 2014 UR - http://www.agriculturejournals.cz/publicFiles/138177.pdf SN - 1214-1178 SN - 1805-9368 VL - 60 IS - 12 SP - 555 EP - 561 PB - Inst. CY - Prague AN - OPUS4-32147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinekamp, Christian A1 - Palmer, Tahlia M. A1 - Al‐Sabbagh, Dominik A1 - May, Anastasia A1 - Prinz, Carsten A1 - Michalik, Stefan A1 - Michalchuk, Adam A. L. A1 - Emmerling, Franziska T1 - Pre‐Activation as a Route for Tuning the Kinetics of Mechanochemical Transformations N2 - Learning to control reaction kinetics is essential for translating any chemical technology into real‐world application. Based on time‐resolved in situ powder X‐ray diffraction data, we demonstrate the opportunity to tune mechanochemical reaction rates through the pre‐activation of the starting reagents. For three model co‐crystal systems, the pre‐activation of the most stable reagent yields up to a ca 10‐fold increase in the reaction rate, whilst negligible kinetic enhancement is seen when the less stable reagent is pre‐activated. Moreover, we demonstrate how the polymorphic outcome of mechano‐co‐crystallization is also sensitive to pre‐activation of the starting material. Our results suggest that reproducibility of mechanochemical processes requires detailed understanding over the origin and history of reagent powders, whilst providing a new conceptual framework to design and control mechanochemical reactions. KW - Mechanochemistry KW - In situ synthesis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649409 DO - https://doi.org/10.1002/anie.202516632 SN - 1433-7851 SP - 1 EP - 7 PB - Wiley VHC-Verlag AN - OPUS4-64940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -