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Skinner JP, Palar S, Allen C, Raderstorf A, Blake P, Morán Reyes A, Berg RN, Muse C, Robles A, Hamdan N, Chu MY, Delgado AG. Acetylene Tunes Microbial Growth During Aerobic Cometabolism of Trichloroethene. Environ Sci Technol 2024; 58:6274-6283. [PMID: 38531380 PMCID: PMC11008246 DOI: 10.1021/acs.est.3c08068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/28/2024] [Accepted: 02/29/2024] [Indexed: 03/28/2024]
Abstract
Microbial aerobic cometabolism is a possible treatment approach for large, dilute trichloroethene (TCE) plumes at groundwater contaminated sites. Rapid microbial growth and bioclogging pose a persistent problem in bioremediation schemes. Bioclogging reduces soil porosity and permeability, which negatively affects substrate distribution and contaminant treatment efficacy while also increasing the operation and maintenance costs of bioremediation. In this study, we evaluated the ability of acetylene, an oxygenase enzyme-specific inhibitor, to decrease biomass production while maintaining aerobic TCE cometabolism capacity upon removal of acetylene. We first exposed propane-metabolizing cultures (pure and mixed) to 5% acetylene (v v-1) for 1, 2, 4, and 8 d and we then verified TCE aerobic cometabolic activity. Exposure to acetylene overall decreased biomass production and TCE degradation rates while retaining the TCE degradation capacity. In the mixed culture, exposure to acetylene for 1-8 d showed minimal effects on the composition and relative abundance of TCE cometabolizing bacterial taxa. TCE aerobic cometabolism and incubation conditions exerted more notable effects on microbial ecology than did acetylene. Acetylene appears to be a viable approach to control biomass production that may lessen the likelihood of bioclogging during TCE cometabolism. The findings from this study may lead to advancements in aerobic cometabolism remediation technologies for dilute plumes.
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Affiliation(s)
- Justin P. Skinner
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Skye Palar
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Channing Allen
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Alia Raderstorf
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Presley Blake
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Arantza Morán Reyes
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Instituto
de Energías Renovables, Universidad
Nacional Autónoma de México, Xochicalco s/n, Azteca, Temixco, Morelos 62588, Mexico
| | - Riley N. Berg
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Christopher Muse
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Aide Robles
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
- Haley
& Aldrich, Inc., 400 E Van Buren St., Suite 545, Phoenix, Arizona 85004, United States
| | - Nasser Hamdan
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
| | - Min-Ying Chu
- Haley
& Aldrich, Inc., 400 E Van Buren St., Suite 545, Phoenix, Arizona 85004, United States
| | - Anca G. Delgado
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering
Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, 650 E Tyler Mall, Tempe, Arizona 85281, United States
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Wang X, Li B, Xia Z, Zhou W, Wu Y, Zhu Z, Zhu G. Effects of Copper(II) Oxide on the Co-Pyrolysis of Waste Polyester Enameled Wires and Poly(vinyl chloride). Polymers (Basel) 2023; 16:27. [PMID: 38201692 PMCID: PMC10781038 DOI: 10.3390/polym16010027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
The emission of chlorinated pollutants is one of the main problems when recovering copper (Cu) via pyrolysis from waste enameled wires. This is mainly attributed to other wastes which possess high poly(vinyl chloride) content, such as electrical wires and cables, which are often recycled together with enameled copper wires. In this research, to control the chlorinated pollutants, copper(II) oxide (CuO) was chosen and demonstrated to be an efficient dechlorinating agent, and CuO did not introduce any impurities that influence the quality of the recovered Cu. The pyrolysis and co-pyrolysis of polyester enameled wires, PVC, and CuO were investigated, and special attention was paid to chlorinated compounds in released pyrolytic products. In particular, the co-pyrolysis of this ternary mixture was studied for the first time, and some new pyrolysis behaviors were discovered. For example, the results of Py-GC/MS analyses showed that the addition of CuO removed about 75% of the chloro-organic products, the main types of which were chloroaromatic compounds rather than the more toxic chloroesters. Moreover, pyrolysis gases were collected and characterized via ion chromatography, and the results showed that the chlorine content in the pyrolysis gases decreased by about 71%. TG analysis indicated that CuO only minimally affected the pyrolysis of polyester paint. However, through the chlorine fixation effect, CuO influenced the dechlorination and dehydrochlorination of PVC, as well as secondary reactions between HCl and pyrolysis products of polyester paint, therefore changing the products and behaviors of co-pyrolysis. Mechanism of reducing chlorine-containing pollutants and reaction mechanism of forming typical pyrolysis products closely correlated to the effects of CuO were also proposed, providing theoretical guidance for the recycling of waste enameled wires.
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Affiliation(s)
- Xiaolu Wang
- Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China; (B.L.); (W.Z.); (Z.Z.); (G.Z.)
| | | | - Zhidong Xia
- Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China; (B.L.); (W.Z.); (Z.Z.); (G.Z.)
| | | | - Yufeng Wu
- Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China; (B.L.); (W.Z.); (Z.Z.); (G.Z.)
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Liu M, Ning Y, Ren M, Fu X, Cui X, Hou D, Wang Z, Cui J, Lin A. Internal Electric Field-Modulated Charge Migration Behavior in MoS 2 /MIL-53(Fe) S-Scheme Heterojunction for Boosting Visible-Light-Driven Photocatalytic Chlorinated Antibiotics Degradation. Small 2023; 19:e2303876. [PMID: 37469229 DOI: 10.1002/smll.202303876] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/06/2023] [Indexed: 07/21/2023]
Abstract
Inadequate photo-generated charge separation, migration, and utilization efficiency limit the photocatalytic efficiency. Herein, a MoS2 /MIL-53(Fe) photocatalyst/activator with the S-scheme heterojunction structure is designed and the charge migration behavior is modulated by the internal electric field (IEF). The IEF intensity is enhanced to 40 mV by modulating band bending potential and the depletion layer length of MoS2 . The photo-generated electron migration process is boosted by constructing the electron migration bridge (Fe-O-S) and modulating the IEF as the driving force, confirmed by the density functional theory calculation. Compared with the pristine materials, the photocurrent density of MoS2 /MIL-53(Fe) is significantly enhanced 27.5 times. Contributed by the visible-light-driven cooperative catalytic degradation and the high-efficiency direct photo-generated electron reduction dichlorination process, satisfactory chlorinated antibiotics removal and detoxification performances are achieved. This study opens up new insights into the application of heterojunctions in photocatalytic activation of PDS in environmental remediation.
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Affiliation(s)
- Meng Liu
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Yuting Ning
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Meng Ren
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Xinping Fu
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Xuedan Cui
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Daibing Hou
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Zihan Wang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Jun Cui
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Aijun Lin
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
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Liu L, Ruan X, Liu H, Fan X, Dong J. Dechlorination of 2,4-dichlorophenol by Fe/Ni nanoparticles: the pathway and the effect of pH and the Ni mass ratio. Environ Technol 2023; 44:3676-3684. [PMID: 35442165 DOI: 10.1080/09593330.2022.2068383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
ABSTRACTThe dechlorination of 2,4-dichlorophenol (2,4-DCP) by a nanoscale Fe/Ni material was investigated at room temperature. 2,4-DCP can be removed more quickly by an Fe/Ni material with 2% Ni. Fe/Ni exhibited excellent adsorption and reduction efficiency toward 2,4-DCP in an aqueous solution over a wide range of pH values. The removal rate of 2,4-DCP exceeded 95% in 60 min in the pH range of 3.0-9.0, and more than 75% was dechlorinated to phenol (CA). The degradation pathway of 2,4-DCP was confirmed based on analysis of the intermediate and end products. A portion of 2,4-DCP was first dechlorinated with a chlorine atom to produce 2-chlorophenol and 4-chlorophenol, and then dechlorination was performed sequentially to form CA. The other portion of 2,4-DCP was dechlorinated to remove two chlorine atoms simultaneously to generate CA. The investigations are essential to the application of iron-based remediation technology.
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Affiliation(s)
- Lujian Liu
- Department of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan, People's Republic of China
- Junji Environmental Technology Co., Ltd., Wuhan, People's Republic of China
| | - Xia Ruan
- Department of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan, People's Republic of China
- Junji Environmental Technology Co., Ltd., Wuhan, People's Republic of China
| | - Hong Liu
- College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan, People's Republic of China
| | - Xianyuan Fan
- College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan, People's Republic of China
| | - Jun Dong
- Department of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan, People's Republic of China
- Junji Environmental Technology Co., Ltd., Wuhan, People's Republic of China
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5
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Gushgari-Doyle S, Olivares CI, Sun M, Alvarez-Cohen L. Syntrophic Interactions Ameliorate Arsenic Inhibition of Solvent-Dechlorinating Dehalococcoides mccartyi. Environ Sci Technol 2023; 57:14237-14247. [PMID: 37695749 PMCID: PMC11055506 DOI: 10.1021/acs.est.3c03807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Interactions and nutrient exchanges among members of microbial communities are important for understanding functional relationships in environmental microbiology. We can begin to elucidate the nature of these complex systems by taking a bottom-up approach utilizing simplified, but representative, community members. Here, we assess the effects of a toxic stress event, the addition of arsenite (As(III)), on a syntrophic co-culture containing lactate-fermenting Desulfovibrio vulgaris Hildenborough and solvent-dechlorinating Dehalococcoides mccartyi strain 195. Arsenic and trichloroethene (TCE) are two highly prevalent groundwater contaminants in the United States, and the presence of bioavailable arsenic is of particular concern at remediation sites in which reductive dechlorination has been employed. While we previously showed that low concentrations of arsenite (As(III)) inhibit the keystone TCE-reducing microorganism, D. mccartyi, this study reports the utilization of physiological analysis, transcriptomics, and metabolomics to assess the effects of arsenic on the metabolisms, gene expression, and nutrient exchanges in the described co-culture. It was found that the presence of D. vulgaris ameliorated arsenic stress on D. mccartyi, improving TCE dechlorination under arsenic-contaminated conditions. Nutrient and amino acid export by D. vulgaris may be a stress-ameliorating exchange in this syntrophic co-culture under arsenic stress, based on upregulation of transporters and increased extracellular nutrients like sarcosine and ornithine. These results broaden our knowledge of microbial community interactions and will support the further development and implementation of robust bioremediation strategies at multi-contaminant sites.
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Affiliation(s)
- Sara Gushgari-Doyle
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, 94720, USA
| | - Christopher I. Olivares
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, 94720, USA
| | - Mohan Sun
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, 94720, USA
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, 94720, USA
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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6
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Zhang L, Wang Q, Xu F, Wang Z. Migration Mechanism of Chlorine during Hydrothermal Treatment of Rigid PVC Plastics. Materials (Basel) 2023; 16:5840. [PMID: 37687533 PMCID: PMC10488432 DOI: 10.3390/ma16175840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023]
Abstract
Rigid PVC plastics (R-PVC) contain large amounts of chlorine, and improper disposal can adversely affect the environment. Nevertheless, there is still a lack of sufficient studies on hydrothermal treatment (HTT) for the efficient dechlorination of R-PVC. To investigate the migration mechanism of chlorine during the HTT of R-PVC, R-PVC is treated with HTT at temperatures ranging from 220 °C to 300 °C for 30 min to 90 min. Hydrochar is characterized via Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy. The results revealed that the hydrothermal temperature is the key factor that affects the dechlorination of R-PVC. Dramatic dechlorination occurs at temperatures ranging from 240 °C to 260 °C, and the dechlorination efficiency increases with the increase in the hydrothermal temperature. The main mechanism for the dechlorination of R-PVC involves the nucleophilic substitution of chlorine by -OH. CaCO3 can absorb HCl released by R-PVC and hinder the autocatalytic degradation of R-PVC; hence, the dechlorination behavior of R-PVC is different from that of pure PVC resins. Based on these results, a possible degradation process for R-PVC is proposed. This study suggests that HTT technology can be utilized to convert organochlorines in R-PVC to calcium chloride, achieving the simultaneous dechlorination of R-PVC and utilization of products.
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Affiliation(s)
- Ling Zhang
- Engineering Research Centre of Oil Shale Comprehensive Utilization, Ministry of Education, Northeast Electric Power University, Jilin City 132012, China
- Jilin Institute of Chemical Technology, Jilin City 132022, China
| | - Qing Wang
- Engineering Research Centre of Oil Shale Comprehensive Utilization, Ministry of Education, Northeast Electric Power University, Jilin City 132012, China
| | - Faxing Xu
- Jilin Feite Environmental Protection Co., Ltd., Jilin City 132200, China
| | - Zhenye Wang
- Jilin Feite Environmental Protection Co., Ltd., Jilin City 132200, China
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Gong L, Chen J, Hu Y, He K, Bylaska EJ, Tratnyek PG, He F. Degradation of Chloroform by Zerovalent Iron: Effects of Mechanochemical Sulfidation and Nitridation on the Kinetics and Mechanism. Environ Sci Technol 2023. [PMID: 37339398 DOI: 10.1021/acs.est.3c02039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
Chloroform (CF) is a widely used chemical reagent and disinfectant and a probable human carcinogen. The extensive literature on halocarbon reduction with zerovalent iron (ZVI) shows that transformation of CF is slow, even with nano, bimetallic, sulfidated, and other modified forms of ZVI. In this study, an alternative method of ZVI modification─involving simultaneous sulfidation and nitridation through mechanochemical ball milling─was developed and shown to give improved degradation of CF (i.e., higher degradation rate and inhibited H2 evolution reaction). The composite material (denoted as S-N(C)-ZVI) gave synergistic effects of nitridation and sulfidation on CF degradation. A complete chemical reaction network (CRN) analysis of CF degradation suggests that O-nucleophile-mediated transformation pathways may be the main route for the formation of the terminal nonchlorinated products (formate, CO, and glycolic polymers) that have been used to explain the undetected products needed for mass balance. Material characterizations of the ZVI recovered after batch experiments showed that sulfidation and nitridation promoted the formation of Fe3O4 on the S-N(C)-ZVI particles, and the effect of aging on CF degradation rates was minor for S-N(C)-ZVI. The synergistic benefits of sulfidation and nitridation on CF degradation were also observed in experiments performed with groundwater.
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Affiliation(s)
- Li Gong
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jingting Chen
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yao Hu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Kai He
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Eric J Bylaska
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, 99354, United States
| | - Paul G Tratnyek
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Feng He
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
- Institute of Environmental Processes and Pollution Control, and School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
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Pan Q, Zhao P, Gao L, Liu H, Hu H, Dong L. In-Depth Study on the Effects of Impurity Ions in Saline Wastewater Electrolysis. Molecules 2023; 28:4576. [PMID: 37375129 DOI: 10.3390/molecules28124576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Concentration followed by electrolysis is one of the most promising ways for saline wastewater treatment, since it could produce H2, Cl2, and an alkaline solution with deacidification potential. However, due to the diversity and difference of wastewater, knowledge on the suitable salt concentration for wastewater electrolysis and the effects of mixed ions are still lacking. In this work, electrolysis experiments of mixed saline water were conducted. The salt concentration for stable dechlorination was explored, with in-depth discussions on the effects of typical ions such as K+, Ca2+, Mg2+, and SO42-. Results showed that K+ had a positive effect on the H2/Cl2 production of saline wastewater through accelerating the mass transfer efficiency in the electrolyte. However, the existence of Ca2+ and Mg2+ had negative effects on the electrolysis performance by forming precipitates, which would adhere to the membrane, reduce the membrane permeability, occupy the active sites on the cathode surface, and also increase the transport resistance of the electrons in the electrolyte. Compared to Mg2+, the damaging effect of Ca2+ on the membrane was even worse. Additionally, the existence of SO42- reduced the current density of the salt solution by affecting the anodic reaction while having less of an effect on the membrane. Overall, Ca2+ ≤ 0.01 mol/L, Mg2+ ≤ 0.1 mol/L and SO42- ≤ 0.01 mol/L were allowable to ensure the continuous and stable dechlorination electrolysis of saline wastewater.
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Affiliation(s)
- Qicheng Pan
- College of Resources and Environment, Hubei University of Technology, Wuhan 430068, China
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Peixuan Zhao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Linxia Gao
- College of Resources and Environment, Hubei University of Technology, Wuhan 430068, China
| | - Huimin Liu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Shenzhen Research Institute of Huazhong University of Science and Technology, Shenzhen 518063, China
| | - Hongyun Hu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Shenzhen Research Institute of Huazhong University of Science and Technology, Shenzhen 518063, China
| | - Lu Dong
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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9
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Chris Felshia S, Gnanamani A. Study on free and entangled binary metal nanocatalysts for removal of 2,4,6-trichlorophenol in aqueous phase: a comparative study. Nanotechnology 2023; 34. [PMID: 37100050 DOI: 10.1088/1361-6528/acd061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 04/26/2023] [Indexed: 05/13/2023]
Abstract
The present study highlights the comparative catalytic removal of 2,4,6-trichlorophenol (TCP) in the aqueous phase by binary nanoparticles in free as well as entangled forms. In brief, binary nanoparticles comprising Fe-Ni are prepared, characterized, and subsequently entangled in reduced graphene oxide (rGO) for better performances. Optimization studies on the mass of free and rGO-entangled binary nanoparticles with respect to TCP concentration and other environmental factors were carried out. Results suggested that free binary nanoparticles at 40 mg ml-1took 300 min to dechlorinate 600 ppm of TCP, whereas rGO-entangled Fe-Ni particles at the same mass took only 190 min to dechlorinate when the pH was maintained at near neutral. In addition, experiments on the reuse of the catalyst with respect to removal efficiency were carried out, and the results implied that, compared to free form, rGO-entangled nanoparticles exemplify more than 98% of removal efficacy even after 5 times of exposure to 600 ppm TCP concentration. The reduction in percentage removal was observed after the sixth exposure. A sequential dechlorination pattern was assessed and confirmed using high-performance liquid chromatography. Further, the phenol-enriched aqueous phase is exposed toBacillus licheniformisSL10, which degrades the phenol effectively within 24 h. In conclusion, the prepared binary nanoparticles, both in free as well as in rGO-entangled forms, effectively dechlorinate 2,4,6-TCP contaminations in the aqueous phase, but with differences in removal duration. Entanglement also makes it easier to reuse the catalyst. Furthermore, microbial phenol degradation allows the aqueous phase to be free of 2, 4, and 6-TCP contamination and allows for the reuse of treated water.
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Affiliation(s)
- S Chris Felshia
- Microbiology Division, CSIR-Central Leather Research Institute, (CLRI), Adyar, Chennai 20, Tamil Nadu, India
| | - A Gnanamani
- Microbiology Division, CSIR-Central Leather Research Institute, (CLRI), Adyar, Chennai 20, Tamil Nadu, India
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10
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Guo S, Xiao W, Liu Z, Zhao D, Chen K, Zhao C, Li X, Li G. Fuel Characteristics and Removal of AAEMs in Hydrochars Derived from Sewage Sludge and Corn Straw. Molecules 2023; 28. [PMID: 36677840 DOI: 10.3390/molecules28020781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Co-hydrothermal carbonization (Co-HTC) of sewage sludge (SS) and corn straw (CS) for fuel preparation is a waste treatment method that reduces the pre-treatment cost of solid waste and biomass fuel. Based on the response surface methodology (RSM), a test was designed to prepare SS and CS hydrochars using a hydrothermal high-pressure reactor. The test examined the higher heating value (HHV) and the concentrations of alkali metals and alkaline earth metals (AAEMs) and Cl. The HHV of SS-hydrochar decreased with an increase in reaction temperature, but that of CS-hydrochar increased. The yield of CS-hydrochar was at 26.74−61.26%, substantially lower than that of SS-hydrochar. Co-hydrochar has the advantages of HHV and an acceptable yield. The HHV of co-hydrochar was 9215.51−12,083.2 kJ/kg, representing an increase of 12.6−47.6% over single component hydrochar, while the yield of co-hydrochar was 41.46−72.81%. In addition, the stabilities of AAEM and Cl in the co-hydrochar were Mg > Ca > K > Na > Cl. SS and CS had a synergistic effect on dechlorination efficiency (DE), which had a negative effect on the removal efficiency (RE) of Ca and Na. The optimal hydrocharization conditions were a temperature of approximately 246.14 °C, a residence time of approximately 90 min, and a mixing ratio of SS−CS of approximately 57.18%. The results offer a way to utilize SS and CS by Co-HTC and convert them into low-chlorine and low-alkali fuel, thus pushing the improvement of this promising waste-to-energy technology.
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11
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McFadden M, Reber KP, Sivey JD, Cwiertny DM, LeFevre GH. Microbial Biotransformation Products and Pathways of Dichloroacetamide Herbicide Safeners. Environ Sci Technol Lett 2023; 10:72-78. [PMID: 37091899 PMCID: PMC10111411 DOI: 10.1021/acs.estlett.2c00862] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 11/29/2022] [Indexed: 05/03/2023]
Abstract
Dichloroacetamide safeners are common ingredients in commercial herbicide formulations. We previously investigated the environmental fate of dichloroacetamides via photolysis and hydrolysis, but other potentially important, environmentally relevant fate processes remain uncharacterized and may yield products of concern. Here, we examined microbial biotransformation of two dichloroacetamide safeners, benoxacor and dichlormid, to identify products and elucidate pathways. Using aerobic microcosms inoculated with river sediment, we demonstrated that microbial biotransformations of benoxacor and dichlormid proceed primarily, if not exclusively, via cometabolism. Benoxacor was transformed by both hydrolysis and microbial biotransformation processes; in most cases, biotransformation rates were faster than hydrolysis rates. We identified multiple novel products of benoxacor and dichlormid not previously observed for microbial processes, with several products similar to those reported for structurally related chloroacetamide herbicides, thus indicating potential for conserved biotransformation mechanisms across both chemical classes. Observed products include monochlorinated species such as the banned herbicide CDAA (from dichlormid), glutathione conjugates, and sulfur-containing species. We propose a transformation pathway wherein benoxacor and dichlormid are first dechlorinated, likely via microbial hydrolysis, and subsequently conjugated with glutathione. This is the first study reporting biological dechlorination of dichloroacetamides to yield monochlorinated products in aerobic environments.
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Affiliation(s)
- Monica
E. McFadden
- Department
of Civil and Environmental Engineering, University of Iowa, 4105 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242, United States
- IIHR-Hydroscience
and Engineering, University of Iowa, 100 C. Maxwell Stanley Hydraulics
Laboratory, Iowa City, Iowa 52242, United States
| | - Keith P. Reber
- Department
of Chemistry, Towson University, Towson, Maryland 21252, United States
| | - John D. Sivey
- Department
of Chemistry, Towson University, Towson, Maryland 21252, United States
| | - David M. Cwiertny
- Department
of Civil and Environmental Engineering, University of Iowa, 4105 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242, United States
- IIHR-Hydroscience
and Engineering, University of Iowa, 100 C. Maxwell Stanley Hydraulics
Laboratory, Iowa City, Iowa 52242, United States
- Center
for Health Effects of Environmental Contamination (CHEEC), University of Iowa, 251 North Capitol St., Chemistry Building, Room W195, Iowa City, Iowa 52242, United States
- Public
Policy Center, University of Iowa, 310 South Grand Ave., 209 South
Quadrangle, Iowa City, Iowa 52242, United States
| | - Gregory H. LeFevre
- Department
of Civil and Environmental Engineering, University of Iowa, 4105 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242, United States
- IIHR-Hydroscience
and Engineering, University of Iowa, 100 C. Maxwell Stanley Hydraulics
Laboratory, Iowa City, Iowa 52242, United States
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12
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Abstract
The use of sodium bisulfite as an electron donor to quench chloramine disinfectant residuals in municipal wastewater effluents prior to discharge incurs the cost of purchasing and transporting bisulfite to the utility and increases the loading of salts to the receiving water. In this study, degradation of chloramine residuals within authentic municipal wastewater effluents was achieved within a 30 min timescale using a reductive electrochemical reactor, which supplied electrons via a stainless-steel cathode under galvanostatic conditions without an ion exchange membrane separating the cathode and anode. Application of a 0.26 mA/cm2 cathodic current density reduced chloramines to ammonia and avoided oxidation at the IrO2-coated titanium anode of chloride to chlorine or chlorate and of ammonia to nitrite or nitrate. Net chloramine production was observed at a higher current density (2 mA/cm2). Chloramine degradation rates and Coulombic efficiencies were highest and electrical energy per order (EEO) values were lowest for the 304-grade stainless-steel cathode, which contains the highest nickel content, and for a stainless-steel cathode with a high surface area. Differences in ionic strength and pH were less important. For chloraminated municipal wastewater samples, the highest Coulombic efficiency was 4.1% and the lowest EEO value was 0.08 kWh/m3. An initial comparison indicated that the electricity cost associated with this EEO value would be comparable to the cost of sodium bisulfite for areas with low electricity costs.
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Affiliation(s)
- Cindy Weng
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California94305, United States
| | - Marlena M Hinkle
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California94305, United States
| | - William A Mitch
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California94305, United States
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13
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Teng D, Qu J, Li P, Jin P, Zhang J, Zhang Y, Cao Y. Heterostructured α-Bi 2O 3/BiOCl Nanosheet for Photocatalytic Applications. Nanomaterials (Basel) 2022; 12:3631. [PMID: 36296821 PMCID: PMC9608947 DOI: 10.3390/nano12203631] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
Photocatalytic degradation of organic pollutants in wastewater is recognized as a promising technology. However, photocatalyst Bi2O3 responds to visible light and suffers from low quantum yield. In this study, the α-Bi2O3 was synthetized and used for removing Cl- in acidic solutions to transform BiOCl. A heterostructured α-Bi2O3/BiOCl nanosheet can be fabricated by coupling Bi2O3 (narrow band gap) with layered BiOCl (rapid photoelectron transmission). During the degradation of Rhodamine B (RhB), the Bi2O3/BiOCl composite material presented excellent photocatalytic activity. Under visible light irradiation for 60 min, the Bi2O3/BiOCl photocatalyst delivered a superior removal rate of 99.9%, which was much higher than pristine Bi2O3 (36.0%) and BiOCl (74.4%). Radical quenching experiments and electron spin resonance spectra further confirmed the dominant effect of electron holes h+ and superoxide radical anions ·O2- for the photodegradation process. This work develops a green strategy to synthesize a high-performance photocatalyst for organic dye degradation.
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Affiliation(s)
- Daoguang Teng
- School of Chemical Engineering and Zhongyuan Critical Metals Laboratory, Zhengzhou University, Zhengzhou 450001, China
| | - Jie Qu
- School of Chemical Engineering and Zhongyuan Critical Metals Laboratory, Zhengzhou University, Zhengzhou 450001, China
| | - Peng Li
- School of Chemical Engineering and Zhongyuan Critical Metals Laboratory, Zhengzhou University, Zhengzhou 450001, China
| | - Peng Jin
- School of Chemical Engineering and Zhongyuan Critical Metals Laboratory, Zhengzhou University, Zhengzhou 450001, China
| | - Jie Zhang
- School of Ecology and Environment, Zhengzhou University, Zhengzhou 450001, China
| | - Ying Zhang
- School of Chemical Engineering and Zhongyuan Critical Metals Laboratory, Zhengzhou University, Zhengzhou 450001, China
| | - Yijun Cao
- School of Chemical Engineering and Zhongyuan Critical Metals Laboratory, Zhengzhou University, Zhengzhou 450001, China
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14
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Zhang CY, Li X, Flor S, Ruiz P, Kruve A, Ludewig G, Lehmler HJ. Metabolism of 3-Chlorobiphenyl (PCB 2) in a Human-Relevant Cell Line: Evidence of Dechlorinated Metabolites. Environ Sci Technol 2022; 56:12460-12472. [PMID: 35994059 PMCID: PMC9573771 DOI: 10.1021/acs.est.2c03687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Lower chlorinated polychlorinated biphenyls (LC-PCBs) and their metabolites make up a class of environmental pollutants implicated in a range of adverse outcomes in humans; however, the metabolism of LC-PCBs in human models has received little attention. Here we characterize the metabolism of PCB 2 (3-chlorobiphenyl), an environmentally relevant LC-PCB congener, in HepG2 cells with in silico prediction and nontarget high-resolution mass spectrometry. Twenty PCB 2 metabolites belonging to 13 metabolite classes, including five dechlorinated metabolite classes, were identified in the cell culture media from HepG2 cells exposed for 24 h to 10 μM or 3.6 nM PCB 2. The PCB 2 metabolite profiles differed from the monochlorinated metabolite profiles identified in samples from an earlier study with PCB 11 (3,3'-dichlorobiphenyl) under identical experimental conditions. A dechlorinated dihydroxylated metabolite was also detected in human liver microsomal incubations with monohydroxylated PCB 2 metabolites but not PCB 2. These findings demonstrate that the metabolism of LC-PCBs in human-relevant models involves the formation of dechlorination products. In addition, untargeted metabolomic analyses revealed an altered bile acid biosynthesis in HepG2 cells. Our results indicate the need to study the disposition and toxicity of complex PCB 2 metabolites, including novel dechlorinated metabolites, in human-relevant models.
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Affiliation(s)
- Chun-Yun Zhang
- Hubei
Key Laboratory of Regional Development and Environmental Response,
Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Xueshu Li
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Susanne Flor
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Patricia Ruiz
- Office
of Innovation and Analytics, Simulation Science Section, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia 30333, United States
| | - Anneli Kruve
- Department
of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius Väg 16, 10691 Stockholm, Sweden
| | - Gabriele Ludewig
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Hans-Joachim Lehmler
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
- Phone: (319) 335-4981. Fax: (319) 335-4290.
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15
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Li Z, Xu J, Meng F, Yang K, Lin D. Modification of Pd Nanoparticles with Lower Work Function Elements for Enhanced Formic Acid Dehydrogenation and Trichloroethylene Dechlorination. ACS Appl Mater Interfaces 2022; 14:30735-30745. [PMID: 35767248 DOI: 10.1021/acsami.2c05099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Catalytic degradation of halogenated contaminants by palladium (Pd) is a promising technology for environmental remediation. However, the low utilization of H by Pd catalyst and its easy poisoning prevent its applications. Here, low work function elements (B or Ag) were incorporated into Fe@C-supported Pd nanoparticles (NPs) to alter their crystalline structure and induce electronic effects, addressing these issues. The Pd mass-normalized dechlorination rates of trichloroethylene (TCE) by Fe@C-Pd-B and Fe@C-Pd-Ag were 51 and 59 times higher than that of unmodified Fe@C-Pd, respectively. The H utilization efficiency of Fe@C-Pd-B and Fe@C-Pd-Ag was 5.4 and 7.2 times higher than that of unmodified Fe@C-Pd, respectively. Various characterizations suggest that the B or Ag incorporation induced the charge redistribution and elevated the electron density of Pd atoms, resulting in the enhanced formic acid (FA) dehydrogenation and TCE dechlorination. Although the Ag incorporation presented a relatively higher H utilization due to the suppressed combination of H and accumulation of unsaturated hydrocarbons (i.e., C2H4), the Fe@C-Pd-Ag was easily deactivated. In contrast, the B incorporation enabled the Pd NPs with a good stability. These findings can guide the rational design of robust Pd-based catalysts for efficient and selective FA dehydrogenation and chlorinated contaminant degradation.
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Affiliation(s)
- Zhenjie Li
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Jiang Xu
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Fanxu Meng
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Kun Yang
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Daohui Lin
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
- Zhejiang Ecological Civilization Academy, Anji 313300, China
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16
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Zhang FL, Li B, Houk KN, Wang YF. Application of the Spin-Center Shift in Organic Synthesis. JACS Au 2022; 2:1032-1042. [PMID: 35647602 PMCID: PMC9131482 DOI: 10.1021/jacsau.2c00051] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 05/09/2023]
Abstract
Spin-center shift (SCS) is a radical process involving 1,2-radical translocation along with a two-electron ionic movement, such as elimination of an adjacent leaving group. Such a process was initially observed in some important biochemical transformations, and the unique property has also attracted considerable interest in synthetic chemistry. Experimental, kinetic, as well as computational studies have been performed, and a series of useful radical transformations have been developed and applied in organic synthesis based on SCS processes in the last 20 years. This Perspective is an overview of radical transformations involving the SCS mechanism.
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Affiliation(s)
- Feng-Lian Zhang
- Department
of Chemistry, University of Science and
Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Bin Li
- Department
of Chemistry, University of Science and
Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - K. N. Houk
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, California 90095, United States
| | - Yi-Feng Wang
- Department
of Chemistry, University of Science and
Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- State
Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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17
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Hotta Y, Yagoshi C, Okazaki R, Ikeda M. Studies on the inhibition of methanogenesis and dechlorination by (4-hydroxyphenyl) chloromethanesulfonate. J Pestic Sci 2022; 47:69-77. [PMID: 35800391 PMCID: PMC9184246 DOI: 10.1584/jpestics.d21-071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/22/2022] [Indexed: 06/15/2023]
Abstract
The purpose of this study was to demonstrate the inhibitory effect of chemicals on methane emissions in paddy soil. We found that (4-hydroxyphenyl) chloromethanesulfonate (C-1) has a methanogenic inhibition activity, and we studied its inhibition mechanism using laboratory tests. The study found that C-1 treatment of flooded soil did not significantly affect the bacterial community but rather the archaeal community; particularly, Methanosarcina spp. C-1 strongly inhibited the aceticlastic methanogenesis route. It was suggested that the inhibitory target of C-1 was different from the well-known methanogenic inhibitor 2-bromoethanesulfonate, which targets methyl-coenzyme M reductase of methanogen. In addition, C-1 had a secondary effect of inhibiting the dechlorination of chlorophenols. Although field trials are required as the next development step, C-1 can be used to reduce methane emissions from paddy fields, one of the largest sources in the agricultural sector.
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Affiliation(s)
- Yudai Hotta
- Life Science Research Institute, Kumiai Chemical Industry Co. Ltd., Tamari, Kakegawa, Shizuoka 436–0011, Japan
| | - Chizu Yagoshi
- Life Science Research Institute, Kumiai Chemical Industry Co. Ltd., Tamari, Kakegawa, Shizuoka 436–0011, Japan
| | - Ryo Okazaki
- Life Science Research Institute, Kumiai Chemical Industry Co. Ltd., Tamari, Kakegawa, Shizuoka 436–0011, Japan
| | - Mitsumasa Ikeda
- Life Science Research Institute, Kumiai Chemical Industry Co. Ltd., Tamari, Kakegawa, Shizuoka 436–0011, Japan
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18
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Gu Z, Zhang Z, Ni N, Hu C, Qu J. Simultaneous Phenol Removal and Resource Recovery from Phenolic Wastewater by Electrocatalytic Hydrogenation. Environ Sci Technol 2022; 56:4356-4366. [PMID: 35194996 DOI: 10.1021/acs.est.1c07457] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Efficient pollutants removal and simultaneous resource recovery from wastewater are of great significance for sustainable development. In this study, an electrocatalytic hydrogenation (ECH) approach was developed to selectively and rapidly transform phenol to cyclohexanol, which possesses high economic value and low toxicity and can be easily recovered from the aqueous solution. A three-dimensional Ru/TiO2 electrode with abundant active sites and massive microflow channels was prepared for efficient phenol transformation. A pseudo-first-order rate constant of 0.135 min-1 was observed for ECH of phenol (1 mM), which was 34-fold higher than that of traditional electrochemical oxidation (EO). Both direct electron transfer and indirect reduction by atomic hydrogen (H*) played pivotal roles in the hydrogenation of phenol ring. The ECH technique also showed excellent performance in a wide pH range of 3-11 and with a high concentration of phenol (10 mM). Moreover, the functional groups (e.g., chloro- and methyl-) on phenol showed little influence on the superiority of the ECH system. This work provides a novel and practical solution for remediation of phenolic wastewater as well as recovery of valuable organic compounds.
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Affiliation(s)
- Zhenao Gu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Beijing 100085, China
| | - Zhiyang Zhang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Nan Ni
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Chengzhi Hu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Beijing 100085, China
| | - Jiuhui Qu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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19
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Meng F, Xu J, Dai H, Yu Y, Lin D. Even Incorporation of Nitrogen into Fe 0 Nanoparticles as Crystalline Fe 4N for Efficient and Selective Trichloroethylene Degradation. Environ Sci Technol 2022; 56:4489-4497. [PMID: 35316036 DOI: 10.1021/acs.est.1c08671] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Surface modification of microscale Fe powder with nitrogen has emerged recently to improve the reactivity of Fe0 for dechlorination. However, it is unclear how an even incorporation of a crystalline iron nitride phase into Fe0 nanoparticles affects their physicochemical properties and performance, or if Fe0 nanoparticles with a varied nitridation degree will act differently. Here, we synthesized nitridated Fe0 nanoparticles with an even distribution of N via a sol-gel and pyrolysis method. Nitridation expanded the Fe0 lattice and provided the Fe4N species, making the materials more hydrophobic and accelerating the electron transfer, compared to un-nitridated Fe0. These properties well explain their reactivity and selectivity toward trichloroethylene (TCE). The TCE degradation rate by nitridated Fe0 (up to 4.8 × 10-2 L m-2 h-1) was much higher (up to 27-fold) than that by un-nitridated Fe0, depending on the nitridation degree. The materials maintained a high electron efficiency (87-95%) due to the greatly suppressed water reactivity (109-127 times lower than un-nitridated Fe0). Acetylene was accumulated as the major product of TCE dechlorination via β-elimination. These findings suggest that the nitridation of Fe0 nanoparticles can change the materials' physicochemical properties, providing high reactivity and selectivity toward chlorinated contaminants for in situ groundwater remediation.
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Affiliation(s)
- Fanxu Meng
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Jiang Xu
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
- Zhejiang Ecological Civilization Academy, Anji 313300, China
| | - Huiwang Dai
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Yunlong Yu
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, China
| | - Daohui Lin
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
- Zhejiang Ecological Civilization Academy, Anji 313300, China
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20
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Nguyen TT, Tsai CK, Horng JJ. Sustainable Recovery of Valuable Nanoporous Materials from High-Chlorine MSWI Fly Ash by Ultrasound with Organic Acids. Molecules 2022; 27:2289. [PMID: 35408687 PMCID: PMC9000401 DOI: 10.3390/molecules27072289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 03/23/2022] [Accepted: 03/30/2022] [Indexed: 11/16/2022] Open
Abstract
The new technology development for municipal solid waste incineration fly ash treatment and reuse is urgent due to landfill shortage and environmental effect of leached hazardous substances. Chlorine (Cl) is worth considering due to its high levels in fly ash. In this study, a treatment process of ultrasound combined with organic acid was used to eliminate Cl from fly ash to enhance its properties for reuse. Taguchi methodology was implemented to design the experiments by controlling four impact factors and the contribution of each factor was evaluated by the ANOVA analysis of variance. Following two treatment steps within 5 min with a solid/liquid ratio of 1:10 at 165 kHz, 98.8% of Cl was eliminated. Solid/liquid ratio was the most prominent factor that contributed to the Cl removal with more than 90%, according to the ANOVA analysis of variance. Tert-butyl alcohol (tBuOH), an •OH radical scavenger, was utilized to examine different effects of ultrasonic cavitation on Cl removal efficiency. A 20 kHz ultrasound was used to explore the influence of multi-frequency ultrasound with different mechanical and sonochemical effects on the fly ash dechlorination. This ultrasonic-assisted organic acid treatment was found to be a time and cost-effective pathway for fly ash Cl removal.
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Affiliation(s)
- Tam Thanh Nguyen
- Faculty of Environment, University of Science (VNUHCM), Ho Chi Minh City 700000, Vietnam
- Vietnam National University Ho Chi Minh City, Ho Chi Minh City 700000, Vietnam
| | - Cheng-Kuo Tsai
- Department of Safety, Health, and Environmental Engineering, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan;
| | - Jao-Jia Horng
- Department of Safety, Health, and Environmental Engineering, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan;
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21
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Zhou Z, Chi Y, Tang Y, Hu J. Effect of calcium-based sorbents on the reduction of chlorinated contaminants during municipal solid waste thermal treatment. Waste Manag Res 2021; 39:1480-1488. [PMID: 34766516 DOI: 10.1177/0734242x21989793] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Chlorinated contaminants are a cause of significant concern in the development of municipal solid waste (MSW) thermal treatment techniques. This study investigates the efficacy of two calcium (Ca)-based in-furnace additives, calcium oxide (CaO), and calcined dolomite (CD), at reducing the levels of chlorinated contaminants during MSW thermal treatment. The results reveal that Ca-based additives could effectively reduce the chlorine (Cl) content by more than 76.8% and 37.3% in the gas and tar phases, respectively. The total concentration and the international total equivalent (I-TEQ) value of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) were significantly higher under the incineration condition than pyrolysis and gasification conditions. Adding CaO could reduce the total concentration and the I-TEQ value of PCDD/Fs by more than 43.4% and 36.7%, respectively. The reduction effect on PCDD/Fs was more significant in the gaseous phase and the tar phase than the solid phase. CD was more effective than CaO at reducing the chlorinated contaminants, including hydrogen chloride, Cl in the tar phase, and PCDD/Fs. Thus, adding Ca-based sorbents in the furnace during MSW pyrolysis and gasification can effectively reduce PCDD/Fs generation. Based on the experimental results, the mechanism of Ca-based sorbents on the high-temperature homogeneous reaction of PCDD/Fs formation was analysed.
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Affiliation(s)
- Zhaozhi Zhou
- Zhejiang Development & Planning Institute, Hangzhou, People's Republic of China
| | - Yong Chi
- State Key Laboratory of Clean Energy Utilisation, Zhejiang University, Hangzhou, People's Republic of China
| | - Yuanjun Tang
- Department of Energy and Environment System Engineering, Zhejiang University of Science and Technology, Hangzhou, People's Republic of China
| | - Junpeng Hu
- State Key Laboratory of Clean Energy Utilisation, Zhejiang University, Hangzhou, People's Republic of China
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22
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Li J, Hu A, Bai S, Yang X, Sun Q, Liao X, Yu CP. Characterization and Performance of Lactate-Feeding Consortia for Reductive Dechlorination of Trichloroethene. Microorganisms 2021; 9:microorganisms9040751. [PMID: 33918519 PMCID: PMC8065584 DOI: 10.3390/microorganisms9040751] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 11/16/2022] Open
Abstract
Understanding the underlying mechanism that drives the microbial community mediated by substrates is crucial to enhance the biostimulation in trichloroethene (TCE)-contaminated sites. Here, we investigated the performance of stable TCE-dechlorinating consortia by monitoring the variations in TCE-related metabolites and explored their underlying assembly mechanisms using 16S rDNA amplicon sequencing and bioinformatics analyses. The monitoring results indicated that three stable TCE-dechlorinating consortia were successfully enriched by lactate-containing anaerobic media. The statistical analysis results demonstrated that the microbial communities of the enrichment cultures changed along with time and were distinguished by their sample sources. The deterministic and stochastic processes were simultaneously responsible for shaping the TCE-dechlorinating community assembly. The indicator patterns shifted with the exhaustion of the carbon source and the pollutants, and the tceA-carrying Dehalococcoides, as an indicator for the final stage samples, responded positively to TCE removal during the incubation period. Pseudomonas, Desulforhabdus, Desulfovibrio and Methanofollis were identified as keystone populations in the TCE-dechlorinating process by co-occurrence network analysis. The results of this study indicate that lactate can be an effective substrate for stimulated bioremediation of TCE-contaminated sites, and the reduction of the stochastic forces or enhancement of the deterministic interventions may promote more effective biostimulation.
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Affiliation(s)
- Jiangwei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anyi Hu
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Shijie Bai
- Institute of Deep Sea Science and Engineering, Chinese Academic of Sciences, Sanya 572000, China;
| | - Xiaoyong Yang
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Qian Sun
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Xu Liao
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Chang-Ping Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
- Water Innovation, Low Carbon and Environmental Sustainability Research Center, National Taiwan University, Taipei 10617, Taiwan
- Correspondence:
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23
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Gushgari-Doyle S, Oremland RS, Keren R, Baesman SM, Akob DM, Banfield JF, Alvarez-Cohen L. Acetylene-Fueled Trichloroethene Reductive Dechlorination in a Groundwater Enrichment Culture. mBio 2021; 12:e02724-20. [PMID: 33531396 PMCID: PMC7858054 DOI: 10.1128/mbio.02724-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/23/2020] [Indexed: 01/14/2023] Open
Abstract
In aquifers, acetylene (C2H2) is a product of abiotic degradation of trichloroethene (TCE) catalyzed by in situ minerals. C2H2 can, in turn, inhibit multiple microbial processes including TCE dechlorination and metabolisms that commonly support dechlorination, in addition to supporting the growth of acetylenotrophic microorganisms. Previously, C2H2 was shown to support TCE reductive dechlorination in synthetic, laboratory-constructed cocultures containing the acetylenotroph Pelobacter sp. strain SFB93 and Dehalococcoides mccartyi strain 195 or strain BAV1. In this study, we demonstrate TCE and perchloroethene (PCE) reductive dechlorination by a microbial community enriched from contaminated groundwater and amended with C2H2 as the sole electron donor and organic carbon source. The metagenome of the stable, enriched community was analyzed to elucidate putative community functions. A novel anaerobic acetylenotroph in the phylum Actinobacteria was identified using metagenomic analysis. These results demonstrate that the coupling of acetylenotrophy and reductive dechlorination can occur in the environment with native bacteria and broaden our understanding of biotransformation at contaminated sites containing both TCE and C2H2IMPORTANCE Understanding the complex metabolisms of microbial communities in contaminated groundwaters is a challenge. PCE and TCE are among the most common groundwater contaminants in the United States that, when exposed to certain minerals, exhibit a unique abiotic degradation pathway in which C2H2 is a product. C2H2 can act as both an inhibitor of TCE dechlorination and of supporting metabolisms and an energy source for acetylenotrophic bacteria. Here, we combine laboratory microcosm studies with computational approaches to enrich and characterize an environmental microbial community that couples two uncommon metabolisms, demonstrating unique metabolic interactions only yet reported in synthetic, laboratory-constructed settings. Using this comprehensive approach, we have identified the first reported anaerobic acetylenotroph in the phylum Actinobacteria, demonstrating the yet-undescribed diversity of this metabolism that is widely considered to be uncommon.
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Affiliation(s)
- Sara Gushgari-Doyle
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, USA
| | | | - Ray Keren
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, USA
- Department of Earth and Planetary Sciences, University of California, Berkeley, California, USA
| | | | | | - Jillian F Banfield
- Department of Earth and Planetary Sciences, University of California, Berkeley, California, USA
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, USA
- Earth and Environmental Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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24
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Brumovský M, Filip J, Malina O, Oborná J, Sracek O, Reichenauer TG, Andrýsková P, Zbořil R. Core-Shell Fe/FeS Nanoparticles with Controlled Shell Thickness for Enhanced Trichloroethylene Removal. ACS Appl Mater Interfaces 2020; 12:35424-35434. [PMID: 32640155 PMCID: PMC7404211 DOI: 10.1021/acsami.0c08626] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/07/2020] [Indexed: 05/28/2023]
Abstract
Zero-valent iron nanoparticles (nZVI) treated by reduced sulfur compounds (i.e., sulfidated nZVI, S-nZVI) have attracted increased attention as promising materials for environmental remediation. While the preparation of S-nZVI and its reactions with various groundwater contaminants such as trichloroethylene (TCE) were already a subject of several studies, nanoparticle synthesis procedures investigated so far were suited mainly for laboratory-scale preparation with only a limited possibility of easy and cost-effective large-scale production and FeS shell property control. This study presents a novel approach for synthesizing S-nZVI using commercially available nZVI particles that are treated with sodium sulfide in a concentrated slurry. This leads to S-nZVI particles that do not contain hazardous boron residues and can be easily prepared off-site. The resulting S-nZVI exhibits a core-shell structure where zero-valent iron is the dominant phase in the core, while the shell contains mostly amorphous iron sulfides. The average FeS shell thickness can be controlled by the applied sulfide concentration. Up to a 12-fold increase in the TCE removal and a 7-fold increase in the electron efficiency were observed upon amending nZVI with sulfide. Although the FeS shell thickness correlated with surface-area-normalized TCE removal rates, sulfidation negatively impacted the particle surface area, resulting in an optimal FeS shell thickness of approximately 7.3 nm. This corresponded to a particle S/Fe mass ratio of 0.0195. At all sulfide doses, the TCE degradation products were only fully dechlorinated hydrocarbons. Moreover, a nearly 100% chlorine balance was found at the end of the experiments, further confirming complete TCE degradation and the absence of chlorinated transformation products. The newly synthesized S-nZVI particles thus represent a promising remedial agent applicable at sites contaminated with TCE.
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Affiliation(s)
- Miroslav Brumovský
- Regional
Centre of Advanced Technologies and Materials, Palacký University Olomouc, Šlechtitelů 27, Olomouc 783 71, Czech
Republic
- Department
of Environmental Geosciences, Centre for Microbiology and Environmental
Systems Science, University of Vienna, Althanstraße 14, UZA II, Vienna 1090, Austria
| | - Jan Filip
- Regional
Centre of Advanced Technologies and Materials, Palacký University Olomouc, Šlechtitelů 27, Olomouc 783 71, Czech
Republic
| | - Ondřej Malina
- Regional
Centre of Advanced Technologies and Materials, Palacký University Olomouc, Šlechtitelů 27, Olomouc 783 71, Czech
Republic
| | - Jana Oborná
- Regional
Centre of Advanced Technologies and Materials, Palacký University Olomouc, Šlechtitelů 27, Olomouc 783 71, Czech
Republic
| | - Ondra Sracek
- Department
of Geology of Science, Palacký University
Olomouc, 17 listopadu 12, Olomouc 771 46, Czech Republic
| | - Thomas G. Reichenauer
- AIT
Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, Tulln an der Donau 3430, Austria
| | - Pavlína Andrýsková
- Regional
Centre of Advanced Technologies and Materials, Palacký University Olomouc, Šlechtitelů 27, Olomouc 783 71, Czech
Republic
| | - Radek Zbořil
- Regional
Centre of Advanced Technologies and Materials, Palacký University Olomouc, Šlechtitelů 27, Olomouc 783 71, Czech
Republic
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Laskar M, Kasai T, Awata T, Katayama A. Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor. Int J Environ Res Public Health 2020; 17:ijerph17124211. [PMID: 32545640 PMCID: PMC7344539 DOI: 10.3390/ijerph17124211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 01/04/2023]
Abstract
The utilization of extracellular electron transfer by microorganism is highly engaging for remediation of toxic pollutants under “energy-starved” conditions. Humin, an organo-mineral complex of soil, has been instrumental as an external electron mediator for suitable electron donors in the remediative works of reductive dehalogenation, denitrification, and so forth. Here, we report, for the first time, that humin assists microbial acetogenesis as the extracellular electron donor using the electron acceptor CO2. Humin was obtained from Kamajima paddy soil, Japan. The anaerobic acetogenic consortium in mineral medium containing CO2/HCO3− as the inorganic carbon source used suspended humin as the energy source under mesophilic dark conditions. Retardation of acetogenesis under the CO2-deficient conditions demonstrated that humin did not function as the organic carbon source but as electron donor in the CO2-reducing acetogenesis. The consortium with humin also achieved anaerobic dechlorination with limited methanogenic activity. Total electron-donating capacity of humin was estimated at about 87 µeeq/g-humin. The metagenomic sequencing of 16S rRNA genes showed the predominance of Firmicutes (71.8 ± 2.5%) in the consortium, and Lachnospiraceae and Ruminococcaceae were considered as the CO2-reducing acetogens in the consortium. Thus, microbial fixation of CO2 using humin introduces new insight to the holistic approach for sustainable treatment of contaminants in environment.
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Affiliation(s)
- Mahasweta Laskar
- Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan; (M.L.); (T.K.)
- Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan
| | - Takuya Kasai
- Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan; (M.L.); (T.K.)
- Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan
| | - Takanori Awata
- National Institute for Land and Infrastructure Management, Tsukuba 305-0804, Japan;
| | - Arata Katayama
- Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan; (M.L.); (T.K.)
- Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan
- Correspondence: ; Tel.: +81-(0)52-789-5856
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26
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Nie Z, Wang N, Xia X, Xia J, Liu H, Zhou Y, Deng Y, Xue Z. Biogenic FeS promotes dechlorination and thus de-cytotoxity of trichloroethylene. Bioprocess Biosyst Eng 2020; 43:1791-1800. [PMID: 32424693 DOI: 10.1007/s00449-020-02369-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 04/29/2020] [Indexed: 12/27/2022]
Abstract
Abiotic iron monosulfide (FeS) has attracted growing interests in dechlorinating trichloroethylene (TCE) in anoxic groundwater, but it is still unclear how biogenic FeS affects the dechlorination and thus the cytotoxity of TCE. In this work, a biogenic FeS was synthesized by Shewanella oneidensis MR-1 with addition of ferrihydrite and S0, and it was used for dechlorination of TCE in alkaline environment and the de-cytotoxicity was evaluated by the growth of Synechocystis sp. PCC6803. The results show that the biogenic FeS was of mackinawite, with a loose flower-like mosaic structure. The dechlorination of TCE by the biogenic FeS was accelerated by 6 times than that by abiotic FeS. TCE was dechlorinated mainly by hydrogenolysis to form dichloroethane (C2H2Cl2), vinyl chloride (C2H3Cl), and finally ethylene, accompanied with transformation of both Fe2+ to Fe3+ and monosulfide to disulfide and polysulfide on the biogenic FeS surface. The concentration for 50% of maximal inhibition effect (EC50) of TCE to Synechocystis was 486 mg/L and the inhibition to Synechocystis under the EC50 was relieved more significantly on addition of the biogenic FeS than that of abiotic FeS. These results indicate that the biogenic FeS promoted the dechlorination and thus de-cytotoxity of TCE.
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Affiliation(s)
- Zhenyuan Nie
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
- Key Lab of Biometallurgy of Ministry of Education of China, Central South University, Changsha, 410083, China
| | - Na Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Xu Xia
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Jinlan Xia
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China.
- Key Lab of Biometallurgy of Ministry of Education of China, Central South University, Changsha, 410083, China.
| | - Hongchang Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
- Key Lab of Biometallurgy of Ministry of Education of China, Central South University, Changsha, 410083, China
| | - Yuhang Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Yu Deng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Zhen Xue
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
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27
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Catlin DS, Yang X, Bennett B, Holz RC, Liu D. Structural basis for the hydrolytic dehalogenation of the fungicide chlorothalonil. J Biol Chem 2020; 295:8668-8677. [PMID: 32358058 DOI: 10.1074/jbc.ra120.013150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/29/2020] [Indexed: 11/06/2022] Open
Abstract
Cleavage of aromatic carbon-chlorine bonds is critical for the degradation of toxic industrial compounds. Here, we solved the X-ray crystal structure of chlorothalonil dehalogenase (Chd) from Pseudomonas sp. CTN-3, with 15 of its N-terminal residues truncated (ChdT), using single-wavelength anomalous dispersion refined to 1.96 Å resolution. Chd has low sequence identity (<15%) compared with all other proteins whose structures are currently available, and to the best of our knowledge, we present the first structure of a Zn(II)-dependent aromatic dehalogenase that does not require a coenzyme. ChdT forms a "head-to-tail" homodimer, formed between two α-helices from each monomer, with three Zn(II)-binding sites, two of which occupy the active sites, whereas the third anchors a structural site at the homodimer interface. The catalytic Zn(II) ions are solvent-accessible via a large hydrophobic (8.5 × 17.8 Å) opening to bulk solvent and two hydrophilic branched channels. Each active-site Zn(II) ion resides in a distorted trigonal bipyramid geometry with His117, His257, Asp116, Asn216, and a water/hydroxide as ligands. A conserved His residue, His114, is hydrogen-bonded to the Zn(II)-bound water/hydroxide and likely functions as the general acid-base. We examined substrate binding by docking chlorothalonil (2,4,5,6-tetrachloroisophtalonitrile, TPN) into the hydrophobic channel and observed that the most energetically favorable pose includes a TPN orientation that coordinates to the active-site Zn(II) ions via a CN and that maximizes a π-π interaction with Trp227 On the basis of these results, along with previously reported kinetics data, we propose a refined catalytic mechanism for Chd-mediated TPN dehalogenation.
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Affiliation(s)
- Daniel S Catlin
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois, USA
| | - Xinhang Yang
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin, USA
| | - Brian Bennett
- Department of Physics, Marquette University, Milwaukee, Wisconsin, USA
| | - Richard C Holz
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin, USA; Department of Chemistry, Colorado School of Mines, Golden, Colorado, USA.
| | - Dali Liu
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois, USA.
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Abstract
Arsenic and trichloroethene (TCE) are among the most prevalent groundwater contaminants in the United States. Co-contamination of these two compounds has been detected at 63% of current TCE-contaminated National Priorities List sites. When in situ TCE reductive dechlorination is stimulated by the addition of fermentable substrates to generate a reducing environment, the presence of arsenic can be problematic because of the potential for increased mobilization and toxicity caused by the reduction of arsenate [As(V)] to arsenite [As(III)]. This study assesses the effects of arsenic exposure on the TCE-dechlorinating activities of Dehalococcoides mccartyi strain 195. Our results indicate that 9.1 μM As(III) caused a 50% decrease in D. mccartyi cell growth. While As(V) concentrations up to 200 μM did not initially impact TCE dechlorination, inhibition was observed in cultures amended with 200 μM As(V) and 100 μM As(V) in 12 and 17 days, respectively, corresponding with the accumulation of As(III). Transcriptomic and metabolomic analyses were performed to evaluate cellular responses to both As(V) and As(III) stress. Amendment of amino acids enhanced arsenic tolerance of D. mccartyi. Results from this study improve our understanding of potential inhibitions of D. mccartyi metabolism caused by arsenic and can inform the design of bioremediation strategies at co-contaminated sites.
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Affiliation(s)
- Sara Gushgari-Doyle
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA
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29
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Moujahid A, Bang JJ, Yan F. Effect of mixing on reductive dechlorination of persistent organic pollutants by Fe/Pd nanoparticles. Water Environ Res 2019; 91:198-207. [PMID: 30710401 DOI: 10.1002/wer.1018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/22/2018] [Accepted: 09/24/2018] [Indexed: 06/09/2023]
Abstract
Herein, we report the comparison of two different mixing methods for reductive dechlorination of gamma-hexachlorocyclohexane (γ-HCH), aldrin, and p, p'-dichlorodiphenyl-trichloroethane (p, p'-DDT), using iron/palladium (Fe/Pd) bimetallic nanoparticles. A noticeable enhancement of the reaction rate was found when the reductive dechlorination reaction was carried out in an ultrasound bath as compared with a platform shaker. These enhancements could be attributed to (a) the continuous cleaning and chemical activation of the surfaces of nanoscale Fe/Pd bimetallic nanoparticles by the combined chemical and physical effects of acoustic cavitation; and (b) the accelerated mass transport rates of target POPs to the surfaces of the Fe/Pd nanoparticles. Finally, the degradation intermediates and final products were determined by gas chromatography/mass spectrometry (GC/MS) analysis and the plausible degradation pathways for γ-HCH, aldrin, and p, p'-DDT by Fe/Pd bimetallic nanoparticles were proposed. PRACTITIONER POINTS: Exposure to POPs is a resilient global environmental and health issue. Fe/Pd bimetallic nanoparticles demonstrated > 90 % removal of POPs in the first 30 minutes of the reaction via ultrasonic mixing. GC-MS analyses provided verification of POPs degradation intermediates and final products.
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Affiliation(s)
- Abdellatif Moujahid
- Department of Chemistry and Biochemistry, North Carolina Central University, Durham, North Carolina
| | - John J Bang
- Department of Environmental, Earth and Geospatial Sciences, North Carolina Central University, Durham, North Carolina
| | - Fei Yan
- Department of Chemistry and Biochemistry, North Carolina Central University, Durham, North Carolina
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30
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Fang L, Shi T, Chen Y, Wu X, Zhang C, Tang X, Li QX, Hua R. Kinetics and Catabolic Pathways of the Insecticide Chlorpyrifos, Annotation of the Degradation Genes, and Characterization of Enzymes TcpA and Fre in Cupriavidus nantongensis X1 T. J Agric Food Chem 2019; 67:2245-2254. [PMID: 30721044 DOI: 10.1021/acs.jafc.9b00173] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Chlorpyrifos is one of the most used organophosphorus insecticides. It is commonly degraded to 3,5,6-trichloro-2-pyridinol (TCP), which is water-soluble and toxic. Bacteria can degrade chlorpyrifos and TCP, but the biodegradation mechanism has not been well-characterized. Recently isolated Cupriavidus nantongensis X1T can completely degrade 100 mg/L chlorpyrifos and 20 mg/L TCP with half-lives of 6 and 8 h, respectively. We annotated a complete gene cluster responsible for TCP degradation in recently sequenced strain X1T. Two key genes, tcpA and fre, were cloned from X1T and transferred and expressed in Escherichia coli BL21(DE3). Degradation of TCP by X1T whole cell was compared with that by the enzymes 2,4,6-trichlorophenol monooxygenase and NAD(P)H:flavin reductase expressed and purified from E. coli BL21(DE3). Novel metabolites of TCP were isolated and characterized, indicating stepwise dechlorination of TCP, which was confirmed by TCP disappearance, mass balance, and detection and formation kinetics of chloride ion from TCP.
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Affiliation(s)
- Liancheng Fang
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Taozhong Shi
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Yifei Chen
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Xiangwei Wu
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Chao Zhang
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Xinyun Tang
- School of Life Science , Anhui Agricultural University , Hefei Anhui 230036 , China
| | - Qing X Li
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
- Department of Molecular Biosciences and Bioengineering , University of Hawaii at Manoa , 1955 East-West Road , Honolulu , Hawaii 96822 , United States
| | - Rimao Hua
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
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31
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Atashgahi S, Liebensteiner MG, Janssen DB, Smidt H, Stams AJM, Sipkema D. Microbial Synthesis and Transformation of Inorganic and Organic Chlorine Compounds. Front Microbiol 2018; 9:3079. [PMID: 30619161 PMCID: PMC6299022 DOI: 10.3389/fmicb.2018.03079] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 11/29/2018] [Indexed: 12/26/2022] Open
Abstract
Organic and inorganic chlorine compounds are formed by a broad range of natural geochemical, photochemical and biological processes. In addition, chlorine compounds are produced in large quantities for industrial, agricultural and pharmaceutical purposes, which has led to widespread environmental pollution. Abiotic transformations and microbial metabolism of inorganic and organic chlorine compounds combined with human activities constitute the chlorine cycle on Earth. Naturally occurring organochlorines compounds are synthesized and transformed by diverse groups of (micro)organisms in the presence or absence of oxygen. In turn, anthropogenic chlorine contaminants may be degraded under natural or stimulated conditions. Here, we review phylogeny, biochemistry and ecology of microorganisms mediating chlorination and dechlorination processes. In addition, the co-occurrence and potential interdependency of catabolic and anabolic transformations of natural and synthetic chlorine compounds are discussed for selected microorganisms and particular ecosystems.
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Affiliation(s)
- Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | | | - Dick B. Janssen
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Hauke Smidt
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Alfons J. M. Stams
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Detmer Sipkema
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
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Jiang Y, Shang Y, Yu S, Liu J. Dechlorination of Hexachlorobenzene in Contaminated Soils Using a Nanometallic Al/CaO Dispersion Mixture: Optimization through Response Surface Methodology. Int J Environ Res Public Health 2018; 15:ijerph15050872. [PMID: 29702570 PMCID: PMC5981911 DOI: 10.3390/ijerph15050872] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 04/18/2018] [Accepted: 04/18/2018] [Indexed: 11/27/2022]
Abstract
Hexachlorobenzene (HCB) contamination of soils remains a significant environmental challenge all over the world. Reductive stabilization is a developing technology that can decompose the HCB with a dechlorination process. A nanometallic Al/CaO (n-Al/CaO) dispersion mixture was developed utilizing ball-milling technology in this study. The dechlorination efficiency of HCB in contaminated soils by the n-Al/CaO grinding treatment was evaluated. Response surface methodology (RSM) was employed to investigate the effects of three variables (soil moisture content, n-Al/CaO dosage and grinding time) and the interactions between these variables under the Box-Behnken Design (BBD). A high regression coefficient value (R2 = 0.9807) and low p value (<0.0001) of the quadratic model indicated that the model was accurate in predicting the experimental results. The optimal soil moisture content, n-Al/CaO dosage, and grinding time were found to be 7% (m/m), 17.7% (m/m), and 24 h, respectively, in the experimental ranges and levels. Under optimal conditions, the dechlorination efficiency was 80%. The intermediate product analysis indicated that dechlorination was the process by stepwise loss of chloride atoms. The main pathway observed within 24 h was HCB → pentachlorobenzene (PeCB) → 1,2,3,4-tetrachlorobenzene (TeCB) and 1,2,4,5-TeCB. The results indicated that the moderate soil moisture content was crucial for the hydrodechlorination of HCB. A probable mechanism was proposed wherein water acted like a hydrogen donor and promoted the hydrodechlorination process. The potential application of n-Al/CaO is an environmentally-friendly and cost-effective option for decontamination of HCB-contaminated soils.
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Affiliation(s)
- Yuhui Jiang
- Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China.
| | - Yixuan Shang
- Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China.
| | - Shuyao Yu
- Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China.
| | - Jianguo Liu
- Key Laboratory for Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education of China, Tsinghua University, Beijing 100084, China.
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Su Y, Wang Y, Owoseni O, Zhang Y, Gamliel DP, Valla JA, McPherson GL, John VT. A Bottle-around-a-Ship Method To Generate Hollow Thin-Shelled Particles Containing Encapsulated Iron Species with Application to the Environmental Decontamination of Chlorinated Compounds. ACS Appl Mater Interfaces 2018; 10:13542-13551. [PMID: 29620856 DOI: 10.1021/acsami.7b14308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Thin-shelled hollow silica particles are synthesized using an aerosol-based process where the concentration of a silica precursor tetraethyl orthosilicate (TEOS) determines the shell thickness. The synthesis involves a novel concept of the salt bridging of an iron salt, FeCl3, to a cationic surfactant, cetyltrimethylammonium bromide (CTAB), which modulates the templating effect of the surfactant on silica porosity. The salt bridging leads to a sequestration of the surfactant in the interior of the droplet with the formation of a dense silica shell around the organic material. Subsequent calcination consistently results in hollow particles with encapsulated iron oxides. Control of the TEOS levels leads to the generation of ultrathin-shelled (∼10 nm) particles which become susceptible to rupture upon exposure to ultrasound. The dense silica shell that is formed is impervious to entry of chemical species. Mesoporosity is restored to the shell through desilication and reassembly, again using CTAB as a template. The mesoporous-shelled hollow particles show good reactivity toward the reductive dichlorination of trichloroethylene (TCE), indicating access of TCE to the particle interior. The ordered mesoporous thin-shelled particles containing active iron species are viable systems for chemical reaction and catalysis.
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Affiliation(s)
| | | | | | | | - David Pierce Gamliel
- Department of Chemical and Biomolecular Engineering , University of Connecticut , Storrs , Connecticut 06269 , United States
| | - Julia A Valla
- Department of Chemical and Biomolecular Engineering , University of Connecticut , Storrs , Connecticut 06269 , United States
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Abstract
Composite membranes were produced with a metallic thin film forming the upper layer of the composite on a porous polymer support. Commercially available membranes were used as supports with both micron and nanometer scale pores. Alloy films of ~110 nm thickness were deposited via magnetron sputtering to produce the top layer of the composite. Dealloying the film with sulfuric acid allowed the creation of a nanoporous film structure with a ligament size of 7.7 ± 2.5 nm. Resulting composite membranes were permeable to water at all stages of production, and a UF PSf membrane with 90 nm of nanoporous Fe/Pd on top showed a flux of 183 LHM/bar. The films were evaluated for dechlorination of toxic polychlorinated biphenyls from water. At a loading of 6.6 mg/L of Pd attached to 13.2 cm2 support in a 2.5 ppm PCB-1 solution with 1.5 ppm dissolved H2, over 90% of PCB-1 was removed from solution in 30 minutes, which produced the expected product biphenyl from the dechlorination reaction.
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Affiliation(s)
- Michael J Detisch
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA
| | - T John Balk
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA
| | - Dibakar Bhattacharyya
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA
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Temme HR, Sande K, Yan T, Novak PJ. Rapid Enrichment of Dehalococcoides-Like Bacteria by Partial Hydrophobic Separation. Appl Environ Microbiol 2017; 83:e02946-16. [PMID: 28087526 DOI: 10.1128/AEM.02946-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/05/2017] [Indexed: 11/20/2022] Open
Abstract
Organohalide-respiring bacteria can be difficult to enrich and isolate, which can limit research on these important organisms. The goal of this research was to develop a method to rapidly (minutes to days) enrich these organisms from a mixed community. The method presented is based on the hypothesis that organohalide-respiring bacteria would be more hydrophobic than other bacteria as they dehalogenate hydrophobic compounds. The method developed tests this hypothesis by separating a portion of putative organohalide-respiring bacteria, those phylogenetically related to Dehalococcoides mccartyi, at the interface between a hydrophobic organic solvent and an aqueous medium. This novel partial separation technique was tested with a polychlorinated biphenyl-enriched sediment-free culture, a tetrachloroethene-enriched digester sludge culture, and uncontaminated lake sediment. Significantly higher fractions, up to 20.4 times higher, of putative organohalide-respiring bacteria were enriched at the interface between the medium and either hexadecane or trichloroethene. The selective partial separation of these putative organohalide-respiring bacteria occurred after 20 min, strongly suggesting that the separation was a result of physical-chemical interactions between the cell surface and hydrophobic solvent. Dechlorination activity postseparation was verified by the production of cis-dichloroethene when amended with tetrachloroethene. A longer incubation time of 6 days prior to separation with trichloroethene increased the total number of putative organohalide-respiring bacteria. This method provides a way to quickly separate some of the putative organohalide-respiring bacteria from other bacteria, thereby improving our ability to study multiple and different bacteria of potential interest and improving knowledge of these bacteria.IMPORTANCE Organohalide-respiring bacteria, bacteria capable of respiring chlorinated contaminants, can be difficult to enrich, which can limit their predictable use for the bioremediation of contaminated sites. This paper describes a method to quickly separate Dehalococcoides-like bacteria, a group of organisms containing organohalide-respiring bacteria, from other bacteria in a mixed community. From this work, Dehalococcoides-like bacteria appear to have a hydrophobic cell surface, facilitating a rapid (20 min) partial separation from a mixed culture at the surface of a hydrophobic liquid. This method was verified in a polychlorinated biphenyl-enriched sediment-free culture, an anaerobic digester sludge, and uncontaminated sediment. The method described can drastically reduce the amount of time required to partially separate Dehalococcoides-like bacteria from a complex mixed culture, improving researchers' ability to study these important bacteria.
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Yang S, Saffarzadeh A, Shimaoka T, Kawano T, Kakuta Y. The impact of thermal treatment and cooling methods on municipal solid waste incineration bottom ash with an emphasis on Cl. Environ Technol 2016; 37:2564-2571. [PMID: 26895375 DOI: 10.1080/09593330.2016.1155651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/14/2016] [Indexed: 06/05/2023]
Abstract
Municipal solid waste incineration (MSWI) bottom-ash products possess qualifications to be utilized in cement production. However, the instant use of bottom ash is inhibited by a number of factors, among which the chlorine (Cl) content is always strictly restricted. In this paper, the unquenched MSWI bottom ash was used as the experimental substance, and the influences of thermal treatment and cooling methods on the content and existence of Cl in the ash residues were investigated. The characterization of the MSWI bottom-ash samples examined by utilizing X-ray diffraction, optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy. The experimental results show that as a function of thermal treatment, the reduction rate of Cl is slight below 15.0%, which is relatively low compared with water washing process. Different cooling methods had impacts on the existing forms of Cl. It was understood that most of Cl existed in the glass phase if the bottom ash was air cooled. Contrarily in case of water-quenched bottom ash, Cl could also be accumulated in the newly-formed quench products as chloride salts or hydrate substances such as Friedel's salt.
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Affiliation(s)
- Shuo Yang
- a China National Institute of Standardization , Beijing , People's Republic of China
- b School of Environment , Tsinghua University , Beijing , People's Republic of China
| | - Amirhomayoun Saffarzadeh
- c Department of Urban and Environmental Engineering, Faculty of Engineering , Kyushu University , Fukuoka , Japan
| | - Takayuki Shimaoka
- c Department of Urban and Environmental Engineering, Faculty of Engineering , Kyushu University , Fukuoka , Japan
| | - Takashi Kawano
- d Energy & Environmental Development Department , Takuma Co., Ltd. , Hyogo , Japan
| | - Yoshitada Kakuta
- d Energy & Environmental Development Department , Takuma Co., Ltd. , Hyogo , Japan
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Zhang W, Jia N, Han X, Qiu Z, Lv S, Lin K, Ying W. A comparison of the dechlorination mechanisms and Ni release styles of chloroalkane and chloroalkene removal using nickel/iron nanoparticles. Environ Technol 2016; 37:2088-2098. [PMID: 26776083 DOI: 10.1080/09593330.2016.1141998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this study, we compared the removal kinetics and Ni release styles of 1,1,1-trichloroethane (1,1,1-TCA), trichloroethylene (TCE), and tetrachloroethene (PCE) that result from the use of Ni/Fe nanoparticles in water. Compared to TCE and PCE, 1,1,1-TCA was more readily removed, and the concentration profiles of the three chlorinated aliphatic hydrocarbons (CAHs) during the reduction processes fit pseudo-first-order reaction rate models well. The surface area-normalized rate constants show that the 11% Ni Ni/Fe nanoparticles, which has the largest Brunauer-Emmett-Teller surface area, has the highest capacity for 1,1,1-TCA removal per unit surface area and that the 6% Ni sample was the best for removing TCE and PCE. The observed by-products suggested that hydrogenolysis was responsible for the dechlorination of CAHs in the presence of Ni/Fe nanoparticles. More Ni2+ was released during the degradation of 1,1,1-TCA than that of TCE and PCE because Ni will reduce the CAHs directly as a zerovalent metal does when hydrogen atoms in the Ni lattice are not sufficient due to the rapid incomplete dechlorination of 1,1,1-TCA. The different modes of adsorption of chloroalkane and chloroalkene onto the surfaces of Ni/Fe particles might play an important role in their dechlorination process.
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Affiliation(s)
- Wei Zhang
- a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process , School of Resources and Environmental Engineering, East China University of Science and Technology , Shanghai , People's Republic of China
| | - Nan Jia
- a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process , School of Resources and Environmental Engineering, East China University of Science and Technology , Shanghai , People's Republic of China
| | - Xiaolin Han
- a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process , School of Resources and Environmental Engineering, East China University of Science and Technology , Shanghai , People's Republic of China
| | - Zhaofu Qiu
- a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process , School of Resources and Environmental Engineering, East China University of Science and Technology , Shanghai , People's Republic of China
| | - Shuguang Lv
- a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process , School of Resources and Environmental Engineering, East China University of Science and Technology , Shanghai , People's Republic of China
| | - Kuangfei Lin
- a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process , School of Resources and Environmental Engineering, East China University of Science and Technology , Shanghai , People's Republic of China
| | - Weichi Ying
- a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process , School of Resources and Environmental Engineering, East China University of Science and Technology , Shanghai , People's Republic of China
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Lu Q, Zhu RL, Yang J, Li H, Liu YD, Lu SG, Luo QS, Lin KF. Natural attenuation model and biodegradation for 1,1,1-trichloroethane contaminant in shallow groundwater. Front Microbiol 2015; 6:839. [PMID: 26379629 PMCID: PMC4548683 DOI: 10.3389/fmicb.2015.00839] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/31/2015] [Indexed: 12/03/2022] Open
Abstract
Natural attenuation is an effective and feasible technology for controlling groundwater contamination. This study investigated the potential effectiveness and mechanisms of natural attenuation of 1,1,1-trichloroethane (TCA) contaminants in shallow groundwater in Shanghai by using a column simulation experiment, reactive transport model, and 16S rRNA gene clone library. The results indicated that the majority of the contaminant mass was present at 2–6 m in depth, the contaminated area was approximately 1000 m × 1000 m, and natural attenuation processes were occurring at the site. The effluent breakthrough curves from the column experiments demonstrated that the effectiveness of TCA natural attenuation in the groundwater accorded with the advection-dispersion-reaction equation. The kinetic parameter of adsorption and biotic dehydrochlorination of TCA was 0.068 m3/kg and 0.0045 d–1. The contamination plume was predicted to diminish and the maximum concentration of TCA decreased to 280 μg/L. The bacterial community during TCA degradation in groundwater belonged to Trichococcus, Geobacteraceae, Geobacter, Mucilaginibacter, and Arthrobacter.
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Affiliation(s)
- Qiang Lu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology , Shanghai, China
| | - Rui-Li Zhu
- Shanghai Academy of Environmental Sciences , Shanghai, China
| | - Jie Yang
- Shanghai Academy of Environmental Sciences , Shanghai, China
| | - Hui Li
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology , Shanghai, China
| | - Yong-Di Liu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology , Shanghai, China
| | - Shu-Guang Lu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology , Shanghai, China
| | - Qi-Shi Luo
- Shanghai Engineering Research Center of Contaminated Sites Remediation, Shanghai Institute for Design and Research on Environmental Engineering , Shanghai, China
| | - Kuang-Fei Lin
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology , Shanghai, China
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Volchek K, Thouin G, Kuang W, Li K, Tezel FH, Brown CE. The release of lindane from contaminated building materials. Environ Sci Pollut Res Int 2014; 21:11844-11855. [PMID: 24652576 PMCID: PMC4177102 DOI: 10.1007/s11356-014-2742-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 03/04/2014] [Indexed: 06/03/2023]
Abstract
The release of the organochlorine pesticide lindane (γ-hexachlorocyclohexane) from several types of contaminated building materials was studied to assess inhalation hazard and decontamination requirements in response to accidental and/or intentional spills. The materials included glass, polypropylene carpet, latex-painted drywall, ceramic tiles, vinyl floor tiles, and gypsum ceiling tiles. For each surface concentration, an equilibrium concentration was determined in the vapour phase of the surrounding air. Vapor concentrations depended upon initial surface concentration, temperature, and type of building material. A time-weighted average (TWA) concentration in the air was used to quantify the health risk associated with the inhalation of lindane vapors. Transformation products of lindane, namely α-hexachlorocyclohexane and pentachlorocyclohexene, were detected in the vapour phase at both temperatures and for all of the test materials. Their formation was greater on glass and ceramic tiles, compared to other building materials. An empiric Sips isotherm model was employed to approximate experimental results and to estimate the release of lindane and its transformation products. This helped determine the extent of decontamination required to reduce the surface concentrations of lindane to the levels corresponding to vapor concentrations below TWA.
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Eske K, Newsome B, Han SG, Murphy M, Bhattacharyya D, Hennig B. PCB 77 dechlorination products modulate pro-inflammatory events in vascular endothelial cells. Environ Sci Pollut Res Int 2014; 21:6354-6364. [PMID: 23504249 PMCID: PMC3728165 DOI: 10.1007/s11356-013-1591-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/20/2013] [Indexed: 05/29/2023]
Abstract
Persistent organic pollutants such as polychlorinated biphenyls (PCBs) are associated with detrimental health outcomes including cardiovascular diseases. Remediation of these compounds is a critical component of environmental policy. Although remediation efforts aim to completely remove toxicants, little is known about the effects of potential remediation byproducts. We previously published that Fe/Pd nanoparticles effectively dechlorinate PCB 77 to biphenyl, thus eliminating PCB-induced endothelial dysfunction using primary vascular endothelial cells. Herein, we analyzed the toxic effects of PCB congener mixtures (representative mixtures of commercial PCBs based on previous dechlorination data) produced at multiple time points during the dechlorination of PCB 77 to biphenyl. Compared with pure PCB 77, exposing endothelial cells to lower chlorinated PCB byproducts led to improved cellular viability, decreased superoxide production, and decreased nuclear factor kappa B activation based on duration of remediation. Presence of the parent compound, PCB 77, led to significant increases in mRNA and protein inflammatory marker expression. These data implicate that PCB dechlorination reduces biological toxicity to vascular endothelial cells.
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Affiliation(s)
- Katryn Eske
- University of Kentucky SRP Center, University of Kentucky, Lexington, KY 40536-0200, USA. Graduate Center for Nutritional Sciences, University of Kentucky, Kentucky SRP Center, Room 599, Wethington Building, 900 South Limestone Street, Lexington, KY 40536-0200, USA
| | - Bradley Newsome
- University of Kentucky SRP Center, University of Kentucky, Lexington, KY 40536-0200, USA. Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA
| | - Sung Gu Han
- University of Kentucky SRP Center, University of Kentucky, Lexington, KY 40536-0200, USA. Department of Food Science of Animal Resources, College of Animal Bioscience and Technology, Konkuk University, Seoul 143-701, Korea
| | - Margaret Murphy
- University of Kentucky SRP Center, University of Kentucky, Lexington, KY 40536-0200, USA. Graduate Center for Nutritional Sciences, University of Kentucky, Kentucky SRP Center, Room 599, Wethington Building, 900 South Limestone Street, Lexington, KY 40536-0200, USA
| | - Dibakar Bhattacharyya
- University of Kentucky SRP Center, University of Kentucky, Lexington, KY 40536-0200, USA. Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506-0046, USA
| | - Bernhard Hennig
- University of Kentucky SRP Center, University of Kentucky, Lexington, KY 40536-0200, USA
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Zahran EM, Bhattacharyya D, Bachas LG. Reactivity of Pd/Fe bimetallic nanotubes in dechlorination of coplanar polychlorinated biphenyls. Chemosphere 2013; 91:165-71. [PMID: 23332879 PMCID: PMC4526161 DOI: 10.1016/j.chemosphere.2012.12.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 12/16/2012] [Indexed: 05/07/2023]
Abstract
A new class of bimetallic materials based on palladium-decorated iron nanotubes is described that demonstrates high reactivity in dechlorination reactions. This high dechlorination efficiency was attributed to the high surface area to volume ratio of the hollow nanotubes structure. Herein, we evaluated the effect of different conditions, such as the nanotube size, and the palladium loading on the efficiency of the dechlorination of PCB 77, a model coplanar polychlorinated biphenyl (PCB), by the Pd/Fe bimetallic nanotubes system. The efficiency of the dechlorination was lowered by decreasing the tube diameter from 200 to 100 nm. In addition, the interior surface as well as the exterior surface of the as-synthesized Pd/Fe bimetallic nanotubes was found to contribute to the high efficiency of the dechlorination of PCB 77. The dechlorination of PCB 77 by Pd/Fe bimetallic nanotubes demonstrated small activation energy indicating diffusion controlled reaction. The as-prepared Pd/Fe bimetallic nanotubes showed extended lifetime activity when used in multiple dechlorination cycles.
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Affiliation(s)
- Elsayed M. Zahran
- Department of Chemistry, University of Miami, Coral Gables, FL 33146
| | - Dibakar Bhattacharyya
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506
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Meeks ND, Smuleac V, Stevens C, Bhattacharyya D. Iron-Based Nanoparticles for Toxic Organic Degradation: Silica Platform and Green Synthesis. Ind Eng Chem Res 2012; 51:9581-9590. [PMID: 22899876 PMCID: PMC3417209 DOI: 10.1021/ie301031u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Iron and iron oxide nanoparticles (NPs) are finding wide applications for the remediation of various toxic chloro-organic compounds (such as trichloroethylene, TCE), via reductive and oxidative processes. In this study, Fe NPs (30-50 nm) are synthesized by reduction from ferric ions immobilized (by ion exchange) on a platform (two types of sulfonated silica particles), in order to prevent the NP agglomeration. Next, the Fe NPs are oxidized and their effectiveness for the oxidative dechlorination of TCE via the heterogeneous decomposition of hydrogen peroxide to OH• on the surface of the iron oxide NPs was demonstrated. For the reductive approach, the use of ascorbic acid as a "green" reducing agent in conjunction with a secondary metal (Pd) inhibits NP oxidation and agglomeration through surface adsorbed species. The Fe/Pd NPs have been successfully applied for the dechlorination of TCE (k(SA), surface-area normalized reaction rate, = 8.1 ×10(-4) L/m(2)h).
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Affiliation(s)
| | - Vasile Smuleac
- Dept. of Chemical and Materials Engineering University of Kentucky Lexington, KY 40506-0046 USA
| | - Christopher Stevens
- Dept. of Chemical and Materials Engineering University of Kentucky Lexington, KY 40506-0046 USA
| | - Dibakar Bhattacharyya
- Dept. of Chemical and Materials Engineering University of Kentucky Lexington, KY 40506-0046 USA
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Dasary SSR, Saloni J, Fletcher A, Anjaneyulu Y, Yu H. Photodegradation of selected PCBs in the presence of Nano-TiO2 as catalyst and H2O2 as an oxidant. Int J Environ Res Public Health 2010; 7:3987-4001. [PMID: 21139872 PMCID: PMC2996220 DOI: 10.3390/ijerph7113987] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 10/25/2010] [Accepted: 11/12/2010] [Indexed: 01/11/2023]
Abstract
Photodegradation of five strategically selected PCBs was carried out in acetonitrile/water 80:20. Quantum chemical calculations reveal that PCBs without any chlorine on ortho-positions are closer to be planar, while PCBs with at least one chlorine atoms at the ortho-positions causes the two benzene rings to be nearly perpendicular. Light-induced degradation of planar PCBs is much slower than the perpendicular ones. The use of nano-TiO2 speeds up the degradation of the planar PCBs, but slows down the degradation of the non-planar ones. The use of H2O2 speeds up the degradation of planar PCBs greatly (by >20 times), but has little effect on non-planar ones except 2,3,5,6-TCB. The relative photodegradation rate is: 2,2′,4,4′-TCB > 2,3,5,6-TCB > 2,6-DCB ≈ 3,3′,4,4′-TCB > 3,4′,5-TCB. The use of H2O2 in combination with sunlight irradiation could be an efficient and “green” technology for PCB remediation.
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Affiliation(s)
- Samuel S R Dasary
- Department of Chemistry and Biochemistry, Jackson State University, 1400 J. R. Lynch Street, P.O. Box 17910, Jackson, MS 39217, USA.
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Smuleac V, Bachas L, Bhattacharyya D. Aqueous - Phase Synthesis of PAA in PVDF Membrane Pores for Nanoparticle Synthesis and Dichlorobiphenyl Degradation. J Memb Sci 2010; 346:310-317. [PMID: 20161475 PMCID: PMC2794051 DOI: 10.1016/j.memsci.2009.09.052] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This paper deals with bimetallic (Fe/Pd) nanoparticle synthesis inside the membrane pores and application for catalytic dechlorination of toxic organic compounds form aqueous streams. Membranes have been used as platforms for nanoparticle synthesis in order to reduce the agglomeration, encountered in solution phase synthesis which leads to a dramatic loss of reactivity. The membrane support, polyvinylidene fluoride (PVDF) was modified by in situ polymerization of acrylic acid in aqueous phase. Subsequent steps included ion exchange with Fe(2+), reduction to Fe(0) with sodium borohydride and Pd deposition. Various techniques, such as STEM, EDX, FTIR and permeability measurements, were used for membrane characterization and showed that bimetallic (Fe/Pd) nanoparticles with an average size of 20-30 nm have been incorporated inside of the PAA-coated membrane pores. The Fe/Pd-modified membranes showed a high reactivity toward a model compound, 2, 2'-dichlorobyphenyl and a strong dependence of degradation on Pd (hydrogenation catalyst) content. The use of convective flow substantially reduces the degradation time: 43% conversion of dichlorobiphenyl to biphenyl can be achieved in less than 40 s residence time. Another important aspect is the ability to regenerate and reuse the Fe/Pd bimetallic systems by washing with a solution of sodium borohydride, because the iron becomes inactivated (corroded) as the dechlorination reaction proceeds.
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Affiliation(s)
- V. Smuleac
- Department of Chemical and Materials Engineering University of Kentucky, Lexington, KY 40506
| | - L. Bachas
- Department of Chemistry University of Kentucky, Lexington, KY 40506
| | - D. Bhattacharyya
- Department of Chemical and Materials Engineering University of Kentucky, Lexington, KY 40506
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Abstract
Membrane-based separation processes have been used extensively for drinking water purification, wastewater treatment, and numerous other applications. More recent developments in membrane functionalization have made the use of membrane science important in diverse fields, from tunable separations to catalysis. The focus of this work is to create a common membrane platform for the incorporation of technologies capable of degrading target pollutants. Functionalized membranes capable of metal capture were created using water-based and solvent-based acrylic acid polymerization to synthesize poly (acrylic acid) (PAA) within poly(vinylidene fluoride) (PVDF) membrane pores. The COO(-) groups of PAA were used to capture Fe(II), which was then either reduced and doped with Pd to form Fe/Pd nanoparticles or used as-is for free radical generation with hydrogen peroxide. Fe/Pd nanoparticles were synthesized within the pores of a PAA/PVDF membrane functionalized via aqueous (green) chemistry and used to dechlorinate trichloroethylene (TCE) and 2,2'-dichlorobiphenyl (DiCB). A PAA/PVDF membrane containing immobilized Fe(III) was used to obtain controlled free radical generation and target organic (pentachlorophenol) degradation within the membrane pore under convective flow conditions.
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Affiliation(s)
- Scott Lewis
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY, USA
| | - Vasile Smuleac
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY, USA
| | - Alex Montague
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY, USA
| | - Leonidas Bachas
- Department of Chemistry, University of Kentucky, Lexington, KY, USA
| | - Dibakar Bhattacharyya
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY, USA
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Yan T, Lapara TM, Novak PJ. The Impact of Sediment Characteristics on PCB-dechlorinating Cultures: Implications for Bioaugmentation. Bioremediat J 2006; 10:143-151. [PMID: 18176633 PMCID: PMC2174835 DOI: 10.1080/10889860601021381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
PCB-dechlorinating cultures with complimentary activities, previously derived from estuarine Baltimore Harbor (B), marine Palos Verdes (P) and riverine Hudson River (H) sediments, were mixed and then inoculated into sterile sediments from the same sources. In the treatments containing sterile B sediment, the different inocula had limited impact on the bacterial community development and on dechlorination patterns, all of which were similar. In treatments containing sterile P or H sediment, however, different inocula resulted in significantly different PCB dechlorination patterns and bacterial communities. The B sediment appeared to support not only the most extensive and rapid dechlorination of the three sediments, but also supported a more diverse bacterial community. This was thought to be a result of nutritional richness, as it was high in organic carbon and micronutrients such as zinc and cobalt. Although mixing three PCB-dechlorinating cultures was able to produce a culture capable of enhanced PCB-dechlorinating activity as compared to single cultures, some activities were lost upon culture transfer. This indicates that care must be taken to establish robust PCB-dechlorinating cultures capable of extensive dechlorination prior to pursuing bioaugmentation. In addition, our results indicate that the concentration and availability of macro- and micro-nutrients could have a significant impact on the microbial community structure, and thus a thorough characterization of the sediment at contaminated sites is essential for implementing bioaugmentation for PCB bioremediation.
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Affiliation(s)
- Tao Yan
- University of Minnesota, Department of Civil Engineering, 500 Pillsbury Drive S.E., Minneapolis, MN 55455-0116
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47
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Ganey PE, Boyd SA. An approach to evaluation of the effect of bioremediation on biological activity of environmental contaminants: dechlorination of polychlorinated biphenyls. Environ Health Perspect 2005; 113:180-5. [PMID: 15687055 PMCID: PMC1277862 DOI: 10.1289/ehp.6935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The effectiveness of bioremediation efforts is assessed traditionally from the loss of the chemical of interest. In some cases, analytical techniques are coupled with evaluation of toxicity to organisms representative of those found in the affected environment or surrogate organisms. Little is known, however, about the effect of remediation of environmental chemicals on potential toxicity to mammalian organisms. We discuss both an approach that employs mammalian cell system bioassays and the criteria for selection of the assays. This approach has been used to evaluate the biological response to mixtures of polychlorinated biphenyls (PCBs) before and after remediation by reductive dechlorination. The dechlorination process used results in accumulation of congeners substituted in only the ortho and para positions and containing fewer chlorines than the starting mixtures. Evaluation of the dechlorinated mixture reveals a loss of biological activity that could be ascribed to coplanar PCBs not containing chlorine in the ortho positions. Conversely, biological activity associated with ortho-substituted PCB congeners is unaffected or increased by remediation. Thus, the results of the bioassays are consistent with the remediation-induced change in the profile of PCB congeners and the known mechanisms of action of PCBs. The results emphasize a need for evaluation of the products of remediation for biological activity in mammalian systems. Furthermore, the approach outlined demonstrates the potential to assess the impact of remediation on a range of biological activities in mammalian cells and thus to estimate positive and negative effects of remediation strategies on toxicity. Future needs in this area of research include assays to evaluate biological effects under conditions of exposure that mimic those found in the environment and models to extrapolate effects to assess risk to people and wildlife.
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Affiliation(s)
- Patricia E Ganey
- Department of Pharmacology and Toxicology, Institute of Environmental Toxicology, Michigan State University, East Lansing, Michigan 48824, USA.
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