Analysis, occurrence and removal of polychlorinated biphenyls (PCBs) in mine water – A review Christian Wolkersdorfer, Oranso Themba Mahlangu, Katrin Wiltschka, Leonard Böhm Environmental Sciences Europe, 2025 Background Polychlorinated biphenyls (PCBs) are persistent organic pollutants, and as such, they are subject to prohibition under the Stockholm Convention, due to their environmental and health effects. Despite their historical utilisation in mining operations, the presence of PCBs in mining influenced water (MIW) remains a subject that has not been adequately investigated. PCBs sorbed to suspended solids are often overlooked in conventional water analyses, contributing to misconceptions about their presence in the environment. Given their bioaccumulative and endocrine-disrupting properties, even minute amounts of PCBs in MIW pose substantial risks to ecosystems and human health. Main body This review article describes the occurrence, environmental fate and treatment of PCBs in MIW and addresses critical knowledge gaps in the mining industry. Historical data demonstrate that PCBs were extensively utilised in mining applications, including dielectric fluids and hydraulic systems. Despite decades of regulatory oversight, residual PCBs persist in MIW, often at concentrations below DIN or ISO detection limits, yet they accumulate through the food web. The sampling challenges posed by the low solubility and sorption of PCBs to solids necessitate the employment of advanced analytical techniques. This study summarises the results of literature searches, laboratory analyses and discussions with international experts. There is still a global lack of monitoring and awareness of PCB contamination in MIW, with Germany being a notable exception. The study’s primary sections address PCB detection methods, sampling techniques and environmental behaviour, emphasising the persistence and mobility of PCBs through adsorption and desorption processes. Treatment strategies encompass biodegradation, filtration, and thermal processes; however, the efficacy of these strategies is contingent on the specific characteristics of the site. Conclusions PCBs in MIW pose a substantial environmental challenge and necessitate multidisciplinary efforts to monitor, understand and eliminate their adverse effects. This review is a comprehensive resource for researchers, regulators and industry representatives, facilitating science-based decisions to protect ecosystems and comply with international environmental standards. Continued research is essential to refine detection methods and develop innovative remediation technologies for PCBs.
Clay Mineral–Hydrophobic Organic Compound Interactions in Miniaturized Adsorption Experiments: Exemplary Studies With Bentonites and Hexachlorobenzene Leonard Böhm, Peter Grančič, Lilli P. Butzke, Stephan Kaufhold, Jan Siemens, et al. Journal of Plant Nutrition and Soil Science, 2025 BackgroundHydrophobic organic compounds (HOCs) are ubiquitous in the environment. Especially halogenated HOCs can pose a major threat to human and environmental health. They show high affinity toward organic matter (OM), and adsorption processes are extensively investigated. Contrary, adsorption to minerals is often considered negligible, and knowledge on HOC interactions with clay minerals (CM) is still scarce.AimsWe aimed to apply an optimized method for the straightforward and sensitive quantification of HOC–CM interactions in miniaturized systems to quantify hexachlorobenzene (HCB) adsorption to native bentonites and to evaluate the influence of different mineral characteristics on adsorption.MethodsHOC–CM interactions were studied in miniaturized batch adsorption experiments with HCB as HOC representative and 21 native bentonites as CM phases. Additionally, five of the bentonites were used as sorbents after wet size fractionation (<2 µm) and homoionic cation exchange (Ca2+). Linear adsorption isotherms and solid–liquid distribution coefficients Kd were calculated after HCB analysis by solid‐phase microextraction (SPME) coupled to GC–MS.ResultsHCB adsorption to selected native bentonites showed a large variation over several orders of magnitude (log Kd 1.8–4.1). Size‐fractionation and Ca2+‐modification tended to slightly decrease the Kd values compared to the five corresponding native bentonites (log Kd: 1.9–3.8 vs. log Kd: 2.0–4.1). Most promising parameters for explaining adsorption strength by different CM characteristics were layer charge density (LCD) and cation exchange capacity (CEC). However, no single factor could be attributed to explain the observed variability of adsorption. The miniaturized batch adsorption method reduces the required amounts of purified CM and toxic chemicals while providing excellent sensitivity and reproducibility.ConclusionsHOC adsorption to native, smectite‐rich bentonites is mostly moderate but can be as high as adsorption to pure OM phases for some bentonites. The variation in adsorption appears to be controlled by a combination of several factors that might include additional factors not previously considered, especially for the bentonites with the strongest adsorption of HCB.
Theoretical Study on Adsorption of Halogenated Benzenes on Montmorillonites Modified With M(I)/M(II) Cations Daniel Tunega, Martin H. Gerzabek, Leonard Böhm Journal of Computational Chemistry, 2025 Halogenated benzenes (HBs) are hydrophobic organic chemicals belonging to persistent organic pollutants. Owing to their persistence, they represent a serious problem in environmental contamination, specifically of soils and sediments. One of the most important physical processes determining the fate of HBs in soils is adsorption to main soil components such as soil organic matter and soil minerals. Smectites, layered clay minerals of the 2:1 type, are common minerals in clay‐rich soils, of which montmorillonite (Mt) is a typical representative. This work focuses on a systematic modeling study of the adsorption mechanism of selected HBs interacting with the basal (001) surface, which is the dominant surface of Mt particles. The HB···Mt interactions were studied by means of a quantum chemical approach based on the density functional theory method. HBs were represented by five molecules, particularly C6F6, C6Cl3F3, C6Cl6, C6Br3Cl3, and C6Br6. In mixed HBs (C6Cl3F3 and C6Br3Cl3) Cl atoms are in 1,3,5 or rather 2,4,6 positions. The effect of a different cation type on adsorption was investigated for M+/M2+‐Mt models with cations from alkali group (M+: Li, K, Na, Rb, Cs) and alkaline earth metal group (M2+: Mg, Ca, Sr., Ba). The calculations were also performed on the gas phase HB···M+/M2+ complexes for comparison. Adsorption energies and distances of the main HB molecular plane from the Mt surface were calculated as a measure of the adsorption strength. The results showed that the strongest HB adsorption is for the Na+‐Mt and Ca2+‐Mt surfaces. The strongest affinity was observed for hexabromobenzene, while the weakest adsorption was found for hexafluorobenzene. The decomposition of the adsorption energy showed that its dominant component is dispersion energy and less important is the cation‐π interaction. The calculated adsorption energies showed a good correlation with experimentally determined log Kd values.
Dissent in the sediment? Lake sediments as archives of short- and long-range impact of anthropogenic activities in northeastern Germany Marcel Pierre Simon, Marlene Schatz, Leonard Böhm, István Papp, Hans-Peter Grossart, et al. Environmental Science and Pollution Research, 2023 The suitability of lake sediment cores to reconstruct past inputs, regional pollution, and usage patterns of pesticides has been shown previously. Until now, no such data exist for lakes in eastern Germany. Therefore, 10 sediment cores (length 1 m) of 10 lakes in eastern Germany, the territory of the former German Democratic Republic (GDR), were collected and cut into 5–10-mm layers. In each layer, concentrations of trace elements (TEs) As, Cd, Cr, Cu, Ni, Pb, S, and Zn, as well as of organochlorine pesticides (OCPs), i.e., dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), were analyzed. A miniaturized solid–liquid extraction technique in conjunction with headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC–MS) was used for the latter. The progression of TE concentrations over time is uniform. It follows a trans-regional pattern and is indicative of activity and policy making in West Germany before 1990 instead of those in the GDR. Of OCPs, only transformation products of DDT were found. Congener ratios indicate a mainly aerial input. In the lakes’ profiles, several regional features and responses to national policies and measures are visible. Dichlorodiphenyldichloroethane (DDD) concentrations reflect the history of DDT use in the GDR. Lake sediments proved to be suitable to archive short- and long-range impacts of anthropogenic activity. Our data can be used to complement and validate other forms of environmental pollution long-term monitoring and to check for the efficiency of pollution countermeasures in the past.
Adsorption of the hydrophobic organic pollutant hexachlorobenzene to phyllosilicate minerals Leonard Böhm, Peter Grančič, Eva Scholtzová, Benjamin Justus Heyde, Rolf-Alexander Düring, et al. Environmental Science and Pollution Research, 2023 Hexachlorobenzene (HCB), a representative of hydrophobic organic chemicals (HOC), belongs to the group of persistent organic pollutants (POPs) that can have harmful effects on humans and other biota. Sorption processes in soils and sediments largely determine the fate of HCB and the risks arising from the compound in the environment. In this context, especially HOC–organic matter interactions are intensively studied, whereas knowledge of HOC adsorption to mineral phases (e.g., clay minerals) is comparatively limited. In this work, we performed batch adsorption experiments of HCB on a set of twelve phyllosilicate mineral sorbents that comprised several smectites, kaolinite, hectorite, chlorite, vermiculite, and illite. The effect of charge and size of exchangeable cations on HCB adsorption was studied using the source clay montmorillonite STx-1b after treatment with nine types of alkali (M+: Li, K, Na, Rb, Cs) and alkaline earth metal cations (M2+: Mg, Ca, Sr, Ba). Molecular modeling simulations based on density functional theory (DFT) calculations to reveal the effect of different cations on the adsorption energy in a selected HCB-clay mineral system accompanied this study. Results for HCB adsorption to minerals showed a large variation of solid–liquid adsorption constants Kd over four orders of magnitude (log Kd 0.9–3.3). Experiments with cation-modified montmorillonite resulted in increasing HCB adsorption with decreasing hydrated radii of exchangeable cations (log Kd 1.3–3.8 for M+ and 1.3–1.4 for M2+). DFT calculations predicted (gas phase) adsorption energies (− 76 to − 24 kJ mol−1 for M+ and − 96 to − 71 kJ mol−1 for M2+) showing a good correlation with Kd values for M2+-modified montmorillonite, whereas a discrepancy was observed for M+-modified montmorillonite. Supported by further calculations, this indicated that the solvent effect plays a relevant role in the adsorption process. Our results provide insight into the influence of minerals on HOC adsorption using HCB as an example and support the relevance of minerals for the environmental fate of HOCs such as for long-term source/sink phenomena in soils and sediments.
On the Nature of Hydrophobic Organic Compound Adsorption to Smectite Minerals Using the Example of Hexachlorobenzene-Montmorillonite Interactions Peter Grančič, Leonard Böhm, Martin H. Gerzabek, Daniel Tunega Minerals, 2023 The fate of chemical pollutants in the environment is determined by various factors including the type and strength of their interactions with reactive surfaces in soils and sediments. In the present work the interactions of hexachlorobenzene (HCB) with the surface of a common clay mineral belonging to the smectite group montmorillonite (MNT) is studied by means of the density functional theory method. The MNT net surface charge, induced by isomorphic substitutions, is systematically varied and compensated by Ca2+ cations. Based on the calculated electron densities, conclusions are drawn revealing the nature of their mutual interactions, the related stability of such surface complexes as well as possible molecular arrangements. It becomes apparent that the dominant contribution to the stability of HCB-MNT complexes arises from the cation-π interactions between the HCB molecule and the nearest compensating Ca2+ cation and thus besides the MNT net surface charge the type and size of the compensating cations are expected to play a crucial role in understanding the HCB adsorption on MNT. This systematic study aims to contribute to a better mechanistic understanding of the interactions between hydrophobic organic compounds and reactive mineral surfaces.
Persistent organic pollutants and mercury in a colony of Antarctic seabirds: higher concentrations in 1998, 2001, and 2003 compared to 2014 to 2016 Nadja D. Kuepper, Leonard Böhm, Christina Braun, Paco Bustamante, Rolf-Alexander Düring, et al. Polar Biology, 2022 Over decades, persistent organic pollutants (POPs) and trace metals like mercury (Hg) have reached the remotest areas of the world such as Antarctica by atmospheric transport. Once deposited in polar areas, low temperatures, and limited solar radiation lead to long environmental residence times, allowing the toxic substances to accumulate in biota. We investigated the load of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs) and metabolites (DDEs, DDDs) in embryos from failed eggs of the smallest seabird breeding in Antarctica, the Wilson's storm-petrel (Oceanites oceanicus) at King George Island (Isla 25 de Mayo). We compared samples of different developmental stages collected in 2001, 2003, and 2014 to 2016 to investigate changes in pollutant concentrations over time. We detected eight PCBs including the dioxin-like (dl) congeners PCB 105 and 118 (ΣPCBs: 59-3403 ng g−1 ww) as well as 4,4’-DDE, and 4,4’-DDD (ΣDDX: 19-1035 ng g−1 ww) in the embryos. Samples from the years 2001 and 2003 showed higher concentrations of PCBs than those from 2014 to 2016. Concentrations of DDX was similar in both time intervals. Furthermore, we determined Hg concentrations in egg membranes from 1998 to 2003, and 2014 to 2016. Similar to PCBs, Hg in egg membranes were higher in 1998 than in 2003, and higher in 2003 than in the years 2014 to 2016, suggesting a slow recovery of the pelagic Antarctic environment from the detected legacy pollutants. Embryos showed an increase in pollutant concentrations within the last third of their development. This finding indicates that contaminant concentrations may differ among developmental stages, and it should be taken into account in analyses on toxic impact during embryogenesis.
Analysis, occurrence and removal of polychlorinated biphenyls (PCBs) in mine water–A review C Wolkersdorfer, OT Mahlangu, K Wiltschka, L Böhm Environmental Sciences Europe 37 (1), 1-36 , 2025 2025 Citations: 1
Clay Mineral–Hydrophobic Organic Compound Interactions in Miniaturized Adsorption Experiments: Exemplary Studies With Bentonites and Hexachlorobenzene L Böhm, P Grančič, LP Butzke, S Kaufhold, J Siemens, D Tunega, ... Journal of Plant Nutrition and Soil Science 188 (5), 788-800 , 2025 2025 Citations: 4
Theoretical Study on Adsorption of Halogenated Benzenes on Montmorillonites Modified With M(I)/M(II) Cations D Tunega, MH Gerzabek, L Böhm Journal of Computational Chemistry 46 (3), e70042 , 2025 2025 Citations: 1
Belastung von Grubenwässern durch polychlorierte Biphenyle (PCB) K Wiltschka, C Wolkersdorfer, RA Düring, L Böhm Mitt Umweltchem Ökotox 30 (1), 14-18 , 2024 2024
Between Underground and the Deep Blue Sea: Contamination of Mine Water Effluents by Polychlorinated Biphenyls (PCBs) K Wiltschka, C Wolkersdorfer, RA Düring, L Böhm ACS ES&T Water 3 (11), 3474–3484 , 2023 2023 Citations: 10
Soil distribution and soil properties in the subalpine region of Kazbegi, Greater Caucasus, Georgia: Physicochemical properties, distribution and genesis T Hanauer, T Grzelachowski, B Vashev, L Böhm, BJ Heyde, ... Geoderma Regional 35, e00734 , 2023 2023 Citations: 3
Dissent in the sediment? Lake sediments as archives of short-and long-range impact of anthropogenic activities in northeastern Germany MP Simon, M Schatz, L Böhm, I Papp, HP Grossart, TJ Andersen, M Bálint, ... Environmental Science and Pollution Research 30 (36), 85867-85888 , 2023 2023 Citations: 6
Adsorption of the hydrophobic organic pollutant hexachlorobenzene to phyllosilicate minerals L Böhm, P Grančič, E Scholtzová, BJ Heyde, RA Düring, J Siemens, ... Environmental Science and Pollution Research 30 (13), 36824-36837 , 2023 2023 Citations: 20
On the Nature of Hydrophobic Organic Compound Adsorption to Smectite Minerals Using the Example of Hexachlorobenzene-Montmorillonite Interactions P Grančič, L Böhm, MH Gerzabek, D Tunega Minerals 13 (2), 280 , 2023 2023 Citations: 6
Concentrations of selected elements and organochlorine pesticides in layers of dated sediment cores of ten lakes in northeastern Germany MP Simon, M Schatz, L Böhm, I Papp, HP Grossart, TJ Andersen, M Bálint, ... 2023 Citations: 1
Towards understanding the interactions between hydrophobic organic compounds and clay minerals P Grancic, L Böhm, M Gerzabek, D Tunega 2022 Goldschmidt Conference , 2022 2022
Persistent organic pollutants and mercury in a colony of Antarctic seabirds: higher concentrations in 1998, 2001, and 2003 compared to 2014 to 2016 ND Kuepper, L Böhm, C Braun, P Bustamante, RA Düring, MM Libertelli, ... Polar Biology 45 (7), 1229-1245 , 2022 2022 Citations: 15
A miniaturized method for fast, simple, and sensitive pesticide analysis in soils MP Simon, D Knuth, L Böhm, K Wiltschka, M Schatz, RA Düring Journal of Soils and Sediments 22 (2), 496-508 , 2022 2022 Citations: 11
Sorption of selected antiparasitics in soils and sediments AP Heinrich, T Zöltzer, L Böhm, M Wohde, S Jaddoudi, Y El Maataoui, ... Environmental Sciences Europe 33 (1), 77 , 2021 2021 Citations: 22
Hydrodechlorination of hexachlorobenzene in a miniaturized nano-Pd (0) reaction system combined with the simultaneous extraction of all dechlorination products K Wiltschka, L Neumann, M Werheid, M Bunge, RA Düring, K Mackenzie, ... Applied Catalysis B: Environmental 275, 119100 , 2020 2020 Citations: 34
Fate of heavy metals and polycyclic aromatic hydrocarbons (PAH) in sewage sludge carbonisates and ashes–A risk assessment to a thermochemical phosphorus-recycling process D Steckenmesser, C Vogel, L Böhm, B Heyde, C Adam Waste Management 78, 576-587 , 2018 2018 Citations: 17
Can solid‐phase microextraction replace solvent extraction for water analysis in fish bioconcentration studies with highly hydrophobic organic chemicals? L Böhm, RA Düring, HJ Bruckert, C Schlechtriem Environmental toxicology and chemistry 36 (11), 2887-2894 , 2017 2017 Citations: 15
Fish bioconcentration studies with column‐generated analyte concentrations of highly hydrophobic organic chemicals C Schlechtriem, L Böhm, R Bebon, HJ Bruckert, RA Düring Environmental toxicology and chemistry 36 (4), 906-916 , 2017 2017 Citations: 18
Automated thin-film microextraction coupled to a flow-through cell: somewhere in between passive and active sampling M Wohde, JO Bartz, L Böhm, C Hartwig, BM Keil, K Martin, RA Düring Analytical and bioanalytical chemistry 409 (8), 1975-1984 , 2017 2017 Citations: 6
Solid-phase Microextraction in Ecotoxicological Testing-Progress with Regard to Highly Hydrophobic Organic Chemical in Bioconcentration Experiments L Böhm Justus Liebig University Giessen , 2017 2017 Citations: 1
MOST CITED SCHOLAR PUBLICATIONS
Calcined biomass-modified bentonite clay for removal of aqueous metal ions BI Olu-Owolabi, AH Alabi, EI Unuabonah, PN Diagboya, L Böhm, ... Journal of Environmental Chemical Engineering 4 (1), 1376-1382 , 2016 2016 Citations: 101
Synthesis of novel palladium (0) nanocatalysts by microorganisms from heavy-metal-influenced high-alpine sites for dehalogenation of polychlorinated dioxins M Schlüter, T Hentzel, C Suarez, M Koch, WG Lorenz, L Böhm, RA Düring, ... Chemosphere 117, 462-470 , 2014 2014 Citations: 86
Passive Dosing in Chronic Toxicity Tests with the Nematode Caenorhabditis elegans F Fischer, L Böhm, S Höss, C Möhlenkamp, E Claus, RA Düring, ... Environmental science & technology 50 (17), 9708-9716 , 2016 2016 Citations: 47
Sorption of highly hydrophobic organic chemicals to organic matter relevant for fish bioconcentration studies L Böhm, C Schlechtriem, RA Düring Environmental science & technology 50 (15), 8316-8323 , 2016 2016 Citations: 38
Hydrodechlorination of hexachlorobenzene in a miniaturized nano-Pd (0) reaction system combined with the simultaneous extraction of all dechlorination products K Wiltschka, L Neumann, M Werheid, M Bunge, RA Düring, K Mackenzie, ... Applied Catalysis B: Environmental 275, 119100 , 2020 2020 Citations: 34
Sorption of selected antiparasitics in soils and sediments AP Heinrich, T Zöltzer, L Böhm, M Wohde, S Jaddoudi, Y El Maataoui, ... Environmental Sciences Europe 33 (1), 77 , 2021 2021 Citations: 22
Partitioning of polycyclic musk compounds in soil and aquatic environment—experimental determination of K DOC L Böhm, RA Düring Journal of Soils and Sediments 10 (4), 708-713 , 2010 2010 Citations: 22
Adsorption of the hydrophobic organic pollutant hexachlorobenzene to phyllosilicate minerals L Böhm, P Grančič, E Scholtzová, BJ Heyde, RA Düring, J Siemens, ... Environmental Science and Pollution Research 30 (13), 36824-36837 , 2023 2023 Citations: 20
Fish bioconcentration studies with column‐generated analyte concentrations of highly hydrophobic organic chemicals C Schlechtriem, L Böhm, R Bebon, HJ Bruckert, RA Düring Environmental toxicology and chemistry 36 (4), 906-916 , 2017 2017 Citations: 18
Fate of heavy metals and polycyclic aromatic hydrocarbons (PAH) in sewage sludge carbonisates and ashes–A risk assessment to a thermochemical phosphorus-recycling process D Steckenmesser, C Vogel, L Böhm, B Heyde, C Adam Waste Management 78, 576-587 , 2018 2018 Citations: 17
Persistent organic pollutants and mercury in a colony of Antarctic seabirds: higher concentrations in 1998, 2001, and 2003 compared to 2014 to 2016 ND Kuepper, L Böhm, C Braun, P Bustamante, RA Düring, MM Libertelli, ... Polar Biology 45 (7), 1229-1245 , 2022 2022 Citations: 15
Can solid‐phase microextraction replace solvent extraction for water analysis in fish bioconcentration studies with highly hydrophobic organic chemicals? L Böhm, RA Düring, HJ Bruckert, C Schlechtriem Environmental toxicology and chemistry 36 (11), 2887-2894 , 2017 2017 Citations: 15
A miniaturized method for fast, simple, and sensitive pesticide analysis in soils MP Simon, D Knuth, L Böhm, K Wiltschka, M Schatz, RA Düring Journal of Soils and Sediments 22 (2), 496-508 , 2022 2022 Citations: 11
Solid-phase microextraction for bioconcentration studies according to OECD TG 305 RA Düring, L Böhm, C Schlechtriem Environmental Sciences Europe 24 (1), 4 , 2012 2012 Citations: 11
Between Underground and the Deep Blue Sea: Contamination of Mine Water Effluents by Polychlorinated Biphenyls (PCBs) K Wiltschka, C Wolkersdorfer, RA Düring, L Böhm ACS ES&T Water 3 (11), 3474–3484 , 2023 2023 Citations: 10
Adsorption of polynuclear aromatic hydrocarbons from aqueous solution: Agrowaste-modified kaolinite vs surfactant modified bentonite EI Unuabonah, BI Olu-Owolabi, L Böhm, RA Düring Bulletin of the Chemical Society of Ethiopia 30 (3), 369-376 , 2016 2016 Citations: 10
Dissent in the sediment? Lake sediments as archives of short-and long-range impact of anthropogenic activities in northeastern Germany MP Simon, M Schatz, L Böhm, I Papp, HP Grossart, TJ Andersen, M Bálint, ... Environmental Science and Pollution Research 30 (36), 85867-85888 , 2023 2023 Citations: 6
On the Nature of Hydrophobic Organic Compound Adsorption to Smectite Minerals Using the Example of Hexachlorobenzene-Montmorillonite Interactions P Grančič, L Böhm, MH Gerzabek, D Tunega Minerals 13 (2), 280 , 2023 2023 Citations: 6
Automated thin-film microextraction coupled to a flow-through cell: somewhere in between passive and active sampling M Wohde, JO Bartz, L Böhm, C Hartwig, BM Keil, K Martin, RA Düring Analytical and bioanalytical chemistry 409 (8), 1975-1984 , 2017 2017 Citations: 6
Clay Mineral–Hydrophobic Organic Compound Interactions in Miniaturized Adsorption Experiments: Exemplary Studies With Bentonites and Hexachlorobenzene L Böhm, P Grančič, LP Butzke, S Kaufhold, J Siemens, D Tunega, ... Journal of Plant Nutrition and Soil Science 188 (5), 788-800 , 2025 2025 Citations: 4