Article
Engineering, Environmental
Miroslav Brumovsky, Vesna Micic, Jana Oborna, Jan Filip, Thilo Hofmann, Daniel Tunega
Summary: This study investigated the performance of iron nitride nanoparticles in dechlorination of chlorinated ethene compounds and found that they exhibited higher dechlorination rates compared to sulfidated nanoscale zero-valent iron particles.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Henning Wienkenjohann, Biao Jin, Massimo Rolle
Summary: This study investigates the impact of diffusive-dispersive processes on isotope fractionation of organic contaminants in groundwater. Through experiments and simulations at different scales, the study demonstrates the significant influence of diffusive-dispersive processes on isotope signatures of chlorinated ethene plumes.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Yuji Yamazaki, Gaku Kitamura, Xiaowei Tian, Ichiro Suzuki, Takeshi Kobayashi, Takaaki Shimizu, Daisuke Inoue, Michihiko Ike
Summary: Thermally enhanced bioremediation at 25 degrees Celsius is effective in dechlorinating PCE and TCE, with significant impact on microbial community structure observed at 35 degrees Celsius.
Article
Engineering, Environmental
Argyro Kokkoli, Nilspeiter Agerholm, Henrik R. Andersen, Kamilla M. S. Kaarsholm
Summary: Chlorinated ethenes are commonly found in groundwater and can be effectively removed through the synergy between ozonation and GAC treatment, with different ozone doses required for different chlorinated ethenes. This approach can significantly increase the lifetime of activated carbon filters in treating chlorinated ethenes-contaminated groundwater.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Review
Environmental Sciences
Moye Luo, Xiaodong Zhang, Xin Zhu, Tao Long, Shaohua Cao, Ran Yu
Summary: This paper provides a comprehensive review of the research progress on the bioremediation, mathematical modeling, and reactive transport simulation of chlorinated ethenes in aquifers over the past three decades. It offers guidance on the selection of appropriate models and software, summarizes the equations, parameters, and applications of existing models, and highlights the operation, benefits, and limitations of available software. Lastly, it emphasizes the importance of reactive transport simulation for the design of in situ bioremediation systems and suggests the need for further research to improve model applicability and support.
ENVIRONMENTAL RESEARCH
(2024)
Article
Environmental Sciences
Qian Li, Zeqin Tang, Dujuan Ou Yang, Jiahui Zhang, Jianmeng Chen, Dongzhi Chen
Summary: The treatment of waste-gas containing CVOCs has become a challenging issue in air pollution control. This study established a bioaugmented BTF and investigated the biodegradation of gaseous DCM and 1,2-DCE. The bioaugmented BTF exhibited faster startup, higher removal efficiencies, and superior mineralization compared to the BTF inoculated with activated sludge alone.
Article
Geochemistry & Geophysics
Edward J. O'Loughlin, David R. Burris
Summary: Chlorinated ethenes, commonly used as solvents and degreasers, have caused significant soil and groundwater contamination. This study found that green rust alone was ineffective in reducing chlorinated ethenes, but the presence of Ag(I) or Cu(II) improved the removal of these pollutants.
Article
Biotechnology & Applied Microbiology
Gao Chen, Fadime Kara Murdoch, Yongchao Xie, Robert W. Murdoch, Yiru Cui, Yi Yang, Jun Yan, Trent A. Key, Frank E. Loffler
Summary: Researchers discovered a new anaerobic bacterium that can efficiently dechlorinate vinyl chloride (VC) to ethene. The bacterium utilizes formate and hydrogen as electron donors for reductive dechlorination, providing new opportunities for effective remediation of VC contamination in groundwater.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Environmental Sciences
Cecilie B. Ottosen, Poul L. Bjerg, Daniel Hunkeler, Jeremy Zimmermann, Nina Tuxen, Dorte Harrekilde, Lars Bennedsen, Gareth Leonard, Laerke Brabaek, Inge Lise Kristensen, Mette M. Broholm
Summary: The study applied an integrated approach to assess in situ biodegradation of TCE contamination enhanced by liquid activated carbon and bioamendments. Dehalococcoides abundances facilitated identification of critical zones with insufficient degradation and provided possible explanations. The combination of isotopic and microbial techniques with distribution and transport information improved understanding of the biodegradation process.
JOURNAL OF CONTAMINANT HYDROLOGY
(2021)
Review
Microbiology
Mohammad Sufian Bin Hudari, Hans Richnow, Carsten Vogt, Ivonne Nijenhuis
Summary: This article summarizes the current knowledge on reductive dehalogenation activities of chlorinated ethenes at different temperatures, including the activity and dehalogenation extent in laboratory isolates and enrichment cultures at different temperatures. It also discusses the indirect effects on biotransformation and the impact of anthropogenic activities related to thermal heat management on groundwater temperature.
FEMS MICROBIOLOGY ECOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Nicola Pastore, Claudia Cherubini, Concetta I. Giasi, Dimitra Rapti
Summary: Developed methodology considers reactive transport and reductive dechlorination of chlorinated solvents in fractured aquifers in a Lagrangian framework, simulating particle motion affected by first-order reactions. Applied to a groundwater contamination case study in Italy, the model provides estimates on transport and degradation processes, serving as a valuable tool in deciding the role of natural attenuation as a treatment option.
HYDROGEOLOGY JOURNAL
(2021)
Article
Engineering, Environmental
Marco C. Mangayayam, Jeffrey Paulo H. Perez, Virginia Alonso-de-Linaje, Knud Dideriksen, Liane G. Benning, Dominique J. Tobler
Summary: This study investigates the reactivity of sulfidated nanoscale zerovalent iron (S-nZVI) when exposed to complex mixtures of chlorinated hydrocarbons (CHCs). The results show that different S-nZVI materials exhibit varying trends in CHC removal, which are influenced by the thickness and crystallinity of the iron sulfide (mackinawite, FeSm) shell. These findings provide important insights for advancing S-nZVI synthesis strategies in specific CHC treatment scenarios.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Environmental Sciences
Marie Czinnerova, Vojtech Stejskal, Kristyna Markova, Jaroslav Nosek, Jakub Riha, Alena Sevcu
Summary: This study summarizes the outcomes of the long-term in-situ application of glycerol for the enhanced reductive dechlorination of chlorinated ethenes (CEs). Glycerol injection resulted in an increase in the abundance of fermentative Firmicutes, leading to the change of groundwater conditions suitable for the growth of organohalide-respiring bacteria (OHRB). The concentrations of pollutants decreased and the final degradation products were ethene and ethane.
Article
Engineering, Environmental
Shuyan Wu, Shichao Cai, Fengyang Qin, Feng He, Tianxi Liu, Xiuping Yan, Zhenyu Wang
Summary: Ball milling is effective in activating and reducing the size of microscale zero valent iron (mZVI) and sulfidating mZVI mechanochemically. However, there are differences in the interaction between chlorinated ethenes (CEs) and ball milled mZVI (mZVIbm) and mechanochemically sulfidated mZVI (S-mZVIbm) that are not well understood. This study found that simple ball milling exposed active Fe0 sites, while mechanochemical sulfidation decreased Fe0 sites and increased S2 sites. The sulfidation process enhanced the reactivity of TCE dechlorination the most, followed by PCE and 1,1-DCE, but reduced the reactivity of trans-DCE, cis-DCE, and VC compared to simple ball milling. Sulfidation also improved the electron efficiency of CE dechlorination, except for cis-DCE and VC. The kSA of cis-DCE, VC, and trans-DCE dechlorination positively correlated with the sulfide content.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Engineering, Environmental
Yalan Mo, Jiang Xu, Lizhong Zhu
Summary: This study reveals the influence of sulfidized nanoscale zerovalent iron (SNZVI) on the dechlorination reactivity and selectivity of chlorinated ethenes (CEs). SNZVI exhibits significantly improved dechlorination reactivity and selectivity compared to zerovalent iron, depending on the chlorine number, chlorine position, and sulfur content of the CEs. By controlling the sulfidation degree of SNZVI, the dechlorination pathway and reactivity of CEs can be altered. These findings are important for the rational design of SNZVI for in situ groundwater remediation of various CEs.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Review
Environmental Sciences
Hamidreza Sharifan, Majid Bagheri, Dan Wang, Joel G. Burken, Christopher P. Higgins, Yanna Liang, Jinxia Liu, Charles E. Schaefer, Jens Blotevogel
Summary: PFASs are a group of persistent organic pollutants that preferentially accumulate in shallow soil horizons and can transform during transport in groundwater, posing challenges for environmental transport and risk management.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Charles E. Schaefer, Dung Nguyen, Emerson Christie, Stefanie Shea, Christopher P. Higgins, Jennifer A. Field
Summary: Bench-scale experiments were conducted to measure and evaluate the desorption kinetics of PFAS from vadose zone soil exposed to AFFFs decades ago. Results showed that desorption equilibrium generally occurred rapidly in the low-OC deep soil, while it was slower in the high-OC shallow soil. Kinetic modeling revealed that the rate of desorption was proportional to PFAS aqueous diffusivity.
JOURNAL OF ENVIRONMENTAL ENGINEERING
(2021)
Article
Engineering, Environmental
Yida Fang, Anderson Ellis, Youn Jeong Choi, Treavor H. Boyer, Christopher P. Higgins, Charles E. Schaefer, Timothy J. Strathmann
Summary: In this study, adsorption of 75 PFASs in diluted AFFF mixture using different resins and GAC was investigated. The results showed that anion-exchange resins exhibited significant adsorption of PFASs compared to other resins and GAC, regardless of the PFAS charge. The study provides insights into the impact of resin properties on PFAS adsorption and guidelines for selecting resins to remove a wider range of PFASs.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Review
Engineering, Environmental
Treavor H. Boyer, Yida Fang, Anderson Ellis, Rebecca Dietz, Youn Jeong Choi, Charles E. Schaefer, Christopher P. Higgins, Timothy J. Strathmann
Summary: This paper critically reviews the available peer-reviewed literature on PFAS removal from water by anion exchange resin (AER), focusing on batch adsorption behavior, impact of water chemistry conditions, continuous-flow adsorption, adsorption modeling, regeneration, and weak-base AER. Future research priorities include improving the underlying science of PFAS-resin interactions, enhancing resin regeneration methods, and conducting comparative life cycle environmental and economic analyses for ion exchange treatment systems.
Article
Engineering, Environmental
Alex Kugler, Hailiang Dong, Chen Li, Cheng Gu, Charles E. Schaefer, Youn Jeong Choi, Danielle Tran, Morgan Spraul, Christopher P. Higgins
Summary: A method of degrading PFOS using hydrated electrons generated from IAA upon UV irradiation was developed, achieving 40-70% defluorination at neutral pH. The spatial proximity of IAA and PFOS on an organic polymer was found to be effective for this process, even in the presence of bicarbonate and chloride ions or natural groundwater. This approach provides an alternative for treating concentrated PFAS solutions under ambient conditions.
Article
Engineering, Environmental
Charles E. Schaefer, Dung Nguyen, Emerson Christie, Stefanie Shea, Christopher P. Higgins, Jennifer Field
Summary: Bench-scale experiments were conducted to evaluate the desorption of poly- and perfluoroalkyl substances (PFAS) from vadose zone soils contaminated with aqueous film-forming foam (AFFF). The results showed that a fraction of the soil-bound PFAS mass was not readily desorbed and could persist for up to 9 months. The non-labile fraction of PFAS mass sorbed to the soil increased with the PFAS organic carbon:water partitioning coefficient (K-oc). The desorption isotherms for the shallow soil were consistent with K-oc-based models derived from adsorption data. These findings provide valuable insight for developing PFAS soil cleanup standards.
JOURNAL OF ENVIRONMENTAL ENGINEERING
(2022)
Article
Engineering, Environmental
John F. Stults, Youn Jeong Choi, Charles E. Schaefer, Tissa H. Illangasekare, Christopher P. Higgins
Summary: Predicting the transport of PFAAs in the vadose zone is crucial for cleanup and risk mitigation. This study introduces a novel experimental method to estimate the chemical partitioning parameters of PFAAs in unsaturated soils, and reevaluates previous research to discover transport nonidealities in unsaturated systems that were previously overlooked.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Environmental Sciences
Charles E. Schaefer, Graig M. Lavorgna, David R. Lippincott, Dung Nguyen, Emerson Christie, Stefanie Shea, Sean O'Hare, Maria C. S. Lemes, Christopher P. Higgins, Jennifer Field
Summary: Using field-deployed lysimeters, this study measured the concentrations of PFAS in soil porewater at a site impacted with AFFF. The study highlighted the potential importance of air-water interfacial sorption on PFAS migration in AFFF-impacted unsaturated soils.
JOURNAL OF CONTAMINANT HYDROLOGY
(2022)
Article
Engineering, Environmental
Charles E. Schaefer, Jennifer Hooper, Mahsa Modiri-Gharehveran, Dina M. Drennan, Ned Beecher, Linda Lee
Summary: This study collected and characterized finished biosolids from seven municipal water resource recovery facilities. The results showed a significant presence of PFAS, with diPAPs being the most common. The total oxidizable precursor assay failed to accurately measure the amount of precursors in the biosolids. Leaching experiments simulating biosolids land application demonstrated sustained leaching of PFAS over a 6-month period.
Article
Engineering, Environmental
Charles E. Schaefer, Maria C. S. Lemes, Trever Schwichtenberg, Jennifer A. Field
Summary: This study investigates the enrichment of PFAS in the water surface microlayer (SML) through bench-scale experiments. The results suggest that PFAS accumulation in the SML is mainly controlled by PFAS sorption at the air-water interface, and the presence of organic matter enhances PFAS uptake at the water surface.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Engineering, Environmental
Raul Tenorio, Andrew C. Maizel, Charles E. Schaefer, Christopher P. Higgins, Timothy J. Strathmann
Summary: UV-sulfite has been found to effectively degrade per- and polyfluoroalkyl substances (PFASs). This study expands the analysis of a wider range of PFASs in aqueous film-forming foam (AFFF) using LC-QTOF-MS suspect screening and semiquantitative analysis. The results highlight the behavior and reactivity of the PFASs, as well as the importance of monitoring PFASs beyond conventional targeted analytical methodologies.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Kaneen E. Christensen, Charles Schaefer, John E. McCray
Summary: This study evaluates the behavior and effectiveness of in situ chemical oxidation (ISCO) using potassium permanganate (KMnO4) to deplete tetrachloroethylene (PCE) dense nonaqueous phase liquid (DNAPL) in a three-dimensional fractured-sandstone network experiment. The results show that mass removal rates during steady state DNAPL dissolution conditions are generally greater than those achieved during ISCO experiments. The formation of reaction byproducts limits the contact between the oxidant and the DNAPL, reducing the mass removal rates.
JOURNAL OF ENVIRONMENTAL ENGINEERING
(2022)
Article
Engineering, Environmental
Anderson C. Ellis, Charlie J. Liu, Yida Fang, Treavor H. Boyer, Charles E. Schaefer, Christopher P. Higgins, Timothy J. Strathmann
Summary: This study compares the performance of regenerable and emerging single-use anion exchange resins for the treatment of PFASs. The study finds that single-use resins outperform regenerable resins in treating long-chain PFASs. The analysis also reveals the affinity and competition among PFASs and resins.
Article
Environmental Sciences
Erin C. Berns-Herrboldt, Xueji You, Jilong Lin, Robert A. Sanford, Albert J. Valocchi, Timothy J. Strathmann, Charles E. Schaefer, Charles J. Werth
Summary: The presence of sulfate-reducing bacteria enhance the reactivity of iron sulfide minerals towards trichloroethene (TCE). Higher ratios of ferrous iron to sulfur result in significant increase in TCE transformation rates when Desulfovibrio vulgaris is present. The characterization of mineral precipitates indicates the presence of mackinawite (FeS), and experimental conditions are within the stability range of FeS. Filtered media without sulfate-reducing bacteria show similar high rates, suggesting the involvement of biogenic redox-active soluble microbial products in maintaining reducing conditions.
Review
Environmental Sciences
Kyle A. Thompson, Soroosh Mortazavian, Dana J. Gonzalez, Charles Bott, Jennifer Hooper, Charles E. Schaefer, Eric R. V. Dickenson
Summary: This paper presents a meta-analysis that assesses the concentrations of per- and polyfluoroalkyl substances (PFAS) in wastewater treatment plants (WWTPs) and their changes over time. The study found that while the concentration of perfluorooctanoic acid (PFOA) increased, the concentration of perfluorosulfonic acid (PFOS) did not significantly change, suggesting that the sorption to sludge is offset by biotransformation of precursor compounds. The occurrence of individual PFAS may vary temporally, and the concentration of PFOA in wastewater effluent showed a decrease in some locations but appeared to increase during the COVID-19 pandemic. However, overall, the concentration of PFOA remains persistently low, with approximately 383 kg of PFOA entering the environment via WWTP effluents annually.