1
|
Zhao L, Li C, Li H, Shu Z, Luo Y, Yang H, Chen Q, Xu W, Zhang W, Tan X. Efficient Cr(VI) removal by pyrite/porous biochar: Critical role of potassium salt and sulphur. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 346:123641. [PMID: 38428791 DOI: 10.1016/j.envpol.2024.123641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/20/2024] [Accepted: 02/22/2024] [Indexed: 03/03/2024]
Abstract
The excessive accumulation of hexavalent chromium (Cr(VI)) in the environment poses a risk to environment and human health. In the present study, a potassium bicarbonate-modified pyrite/porous biochar composite (PKBC) was prepared in a one-step process and applied for the efficient removal of Cr(VI) in wastewater. The results showed that PKBC can significantly remove Cr(VI) within 4 h over a wide range of pH (2-11). Meanwhile, the PKBC demonstrated remarkable resistance towards interference from complex ions. The addition of potassium bicarbonate increased the pore structure of the material and promoted the release of Fe2+. The reduction of Cr(VI) in aqueous solution was primarily attributed to the Fe(II)/Fe(III) redox cycle. The sulphur species achieved Fe(II)/Fe(III) cycle through electron transfer with iron, thus ensuring the continuous reduction capacity of PKBC. Besides, the removal rate was also maintained at more than 85% in the actual water samples treatment process. This work provides a new way to remove hexavalent chromium from wastewater and demonstrates the potential critical role of potassium bicarbonate and sulphur.
Collapse
Affiliation(s)
- Lei Zhao
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Chuang Li
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China; Shenzhen Research Institute of Hunan University, Shenzhen, 518055, PR China
| | - Hong Li
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China; Shenzhen Research Institute of Hunan University, Shenzhen, 518055, PR China
| | - Zihan Shu
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China; Shenzhen Research Institute of Hunan University, Shenzhen, 518055, PR China
| | - Yang Luo
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China; Shenzhen Research Institute of Hunan University, Shenzhen, 518055, PR China
| | - Hailan Yang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Qiang Chen
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Weihua Xu
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Wei Zhang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Xiaofei Tan
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China; Shenzhen Research Institute of Hunan University, Shenzhen, 518055, PR China.
| |
Collapse
|
2
|
He J, Zhang B, Wang Y, Chen S, Dong H. Vanadate Bio-Detoxification Driven by Pyrrhotite with Secondary Mineral Formation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:1807-1818. [PMID: 36598371 DOI: 10.1021/acs.est.2c06184] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Vanadium(V) is a redox-sensitive heavy-metal contaminant whose environmental mobility is strongly influenced by pyrrhotite, a widely distributed iron sulfide mineral. However, relatively little is known about microbially mediated vanadate [V(V)] reduction characteristics driven by pyrrhotite and concomitant mineral dynamics in this process. This study demonstrated efficient V(V) bioreduction during 210 d of operation, with a lifespan about 10 times longer than abiotic control, especially in a stable period when the V(V) removal efficiency reached 44.1 ± 13.8%. Pyrrhotite oxidation coupled to V(V) reduction could be achieved by an enriched single autotroph (e.g., Thiobacillus and Thermomonas) independently. Autotrophs (e.g., Sulfurifustis) gained energy from pyrrhotite oxidation to synthesize organic intermediates, which were utilized by the heterotrophic V(V) reducing bacteria such as Anaerolinea, Bacillus, and Pseudomonas to sustain V(V) reduction. V(V) was reduced to insoluble tetravalent V, while pyrrhotite oxidation mainly produced Fe(III) and SO42-. Secondary minerals including mackinawite (FeS) and greigite (Fe3S4) were produced synchronously, resulting from further transformations of Fe(III) and SO42- by sulfate reducing bacteria (e.g., Desulfatiglans) and magnetotactic bacteria (e.g., Nitrospira). This study provides new insights into the biogeochemical behavior of V under pyrrhotite effects and reveals the previously overlooked mineralogical dynamics in V(V) reduction bioprocesses driven by Fe(II)-bearing minerals.
Collapse
Affiliation(s)
- Jinxi He
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, P. R. China
| | - Baogang Zhang
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, P. R. China
| | - Ya'nan Wang
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, P. R. China
| | - Siming Chen
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, P. R. China
| | - Hailiang Dong
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, School of Earth Science and Resources, China University of Geosciences Beijing, Beijing 100083, P. R. China
| |
Collapse
|
3
|
Xiao W, Ye X, Ye Z, Zhang Q, Zhao S, Chen D, Gao N, Huang M. Responses of microbial community composition and function to biochar and irrigation management and the linkage to Cr transformation in paddy soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 304:119232. [PMID: 35364188 DOI: 10.1016/j.envpol.2022.119232] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 02/25/2022] [Accepted: 03/27/2022] [Indexed: 06/14/2023]
Abstract
Combining biochar with irrigation management to alter the microbial community is a sustainable method for remediating soils contaminated by heavy metals. However, studies on how these treatments promote Cr(VI) reduction are limited, and the corresponding microbial mechanisms are unclear. Therefore, we conducted a pot experiment to explore the responses of soil microbial communities to combined biochar amendment and irrigation management strategies and their involvement in Cr transformation in paddy soils. Six treatments were established using varying concentrations of biochar (0, 1, and 2% [w/w]) combined with two irrigation management strategies (continuous flooding [CF] and dry-wet alternation [DWA]). The results showed that the combined biochar addition and irrigation management strategy significantly altered soil pH, redox potential, organic matter content, and Fe(II) and sulfide concentrations. In addition, the Cr(VI) concentration under CF irrigation management was conspicuously lower (48.2-54.4%) than that under DWA irrigation management. Biochar amendment also resulted in a substantial reduction (8.8-27.4%) in Cr(VI) concentration. Moreover, the changes in soil physicochemical properties remarkably affected the soil microbial community. The microbial diversity and abundance significantly increased with biochar amendment. Furthermore, the combined biochar amendment and CF strategy stimulated the growth of Geobacter- and Anaeromyxobacter-related Fe(III)-reducing bacteria, Gallionella-related Fe(II)-oxidizing bacteria, and Desulfovibro- and Clostridium-related sulfate-reducing bacteria, which simultaneously facilitated the generation of Fe(II) and sulfide, thereby enhancing Cr(VI) reduction. Consequently, our results suggest that the effectively increased abundance of Fe-reducing/oxidizing bacteria and sulfate-reducing bacteria via combined CF irrigation management and biochar addition may be a key factor in reducing Cr(VI) in paddy soil. The keystone genera responsible for Cr(VI) reduction were Geobacter, Anaeromyxobacter, Gallionella, Desulfovibro, and Clostridium. This study provides novel insights into the coupling mechanism of the Fe/S/Cr transformation mediated by Fe-reducing/oxidizing bacteria and sulfate-reducing bacteria.
Collapse
Affiliation(s)
- Wendan Xiao
- Key Laboratory of Information Traceability for Agricultural Products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Xuezhu Ye
- Key Laboratory of Information Traceability for Agricultural Products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.
| | - Zhengqian Ye
- College of Environmental and Resource Sciences, Zhejiang A&F University, Hangzhou, 311300, China
| | - Qi Zhang
- Key Laboratory of Information Traceability for Agricultural Products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Shouping Zhao
- Key Laboratory of Information Traceability for Agricultural Products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - De Chen
- Key Laboratory of Information Traceability for Agricultural Products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Na Gao
- Key Laboratory of Information Traceability for Agricultural Products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Miaojie Huang
- Key Laboratory of Information Traceability for Agricultural Products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| |
Collapse
|
4
|
Qian D, Liu H, Hu F, Song S, Chen Y. Extracellular electron transfer-dependent Cr(VI)/sulfate reduction mediated by iron sulfide nanoparticles. J Biosci Bioeng 2022; 134:153-161. [PMID: 35690565 DOI: 10.1016/j.jbiosc.2022.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 01/18/2023]
Abstract
The slow electron transfer rate is a bottleneck to the biological wastewater treatment. This study evaluated the concomitant biotransformation and nonenzymatic reduction of Cr(VI) mediated by sulfate reducing bacteria (SRB), especially for the reinforcing Cr(VI) reduction via accelerating the electron transfer by the in-situ biosynthesized iron sulfide nanoparticles (FeS NPs). The kinetic results showed that 10 mg/L Cr(VI) was completely removed by pre-cultured FeS NPs within 7 h with kCr(VI) of 2.6 × 10-4 s-1, one magnitude higher than that without FeS NPs. Despite its competing electron to postpone sulfate reduction, the reduction of Cr(VI) was markedly improved via nonenzymatic reactions by the sulfide, the product of sulfate reduction. In the reinforcing system (bio-FeS NP@SRB), the bio-FeS NPs served as an electronic bypass conduit for CoQ could significantly amplify the electron flux, and switch the Cr(VI) reduction from intracellular space to extracellular environment, which had a great detoxification effect on the microorganisms, eventually markedly promoted electron transfer extracellularly and the reduction of Cr(VI). After the long-term acclimatization, Desulfovibrio became the dominant bacteria at the genus level and accounted for the relative abundance of 32%. This study provides an alternative to use biogenic FeS NPs for Cr(VI) remediation.
Collapse
Affiliation(s)
- Danshi Qian
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Huimin Liu
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Fan Hu
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Song Song
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Yuancai Chen
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
| |
Collapse
|
5
|
Nanoscale zero-valent iron coupling with Shewanella oneidensis MR-1 for enhanced reduction/removal of aqueous Cr(VI). Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119488] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
6
|
Tang J, Zhao B, Lyu H, Li D. Development of a novel pyrite/biochar composite (BM-FeS 2@BC) by ball milling for aqueous Cr(VI) removal and its mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2021; 413:125415. [PMID: 33626470 DOI: 10.1016/j.jhazmat.2021.125415] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/27/2021] [Accepted: 02/10/2021] [Indexed: 06/12/2023]
Abstract
As a natural reduction mineral, pyrite (FeS2), was combined with biochar by simply ball milling technology to synthesize FeS2@biochar composite (BM-FeS2@BC) and applied for the removal of hexavalent chromium (Cr(VI)) in aqueous solution. SEM, XRD, FTIR, and XPS characterization results showed that the FeS2 and biochar were successfully combined and biochar suppressed the agglomeration of FeS2. Batch sorption experiments showed that the BM-FeS2@BC700 composite (mass ratio of FeS2-to-biochar = 3:1) had enhanced Cr(VI) removal capacity of 134 mg·g-1, which were 3-25 times higher than those of the corresponding pristine and ball-milled biochar and FeS2. The removal of Cr(VI) by BM-FeS2@BC700 was dosage and pH dependent. The addition of oxalic acid (OA) exhibited a promotion effect on the removal of Cr(VI) by increasing the removal rate of Cr(VI) from 56% to 100%. Reduction, adsorption, and surface complexation were the dominate mechanisms for Cr(VI) removal by BM-FeS2@BC700. At the equilibrium Cr(VI) concentration of 15.7 mg·L-1, 92.25% of Cr(VI) was removed through reduction/precipitation and 8.75% was removed by adsorption/surface complexation. The fitting results of the Langmuir model proved that the removal of Cr(VI) by BM-FeS2@BC700 composite was chemical surface monolayer adsorption. This work demonstrates the potential of ball milling for the preparation of FeS2@BC composite to remove Cr(VI) from water and wastewater.
Collapse
Affiliation(s)
- Jingchun Tang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Beibei Zhao
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Honghong Lyu
- Tianjin Key Laboratory of Clean Energy and pollution control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
| | - Ding Li
- BCIG Environmental Remediation Co., Ltd, Tianjin 300042, China
| |
Collapse
|
7
|
Tang X, Huang Y, Li Y, Wang L, Pei X, Zhou D, He P, Hughes SS. Study on detoxification and removal mechanisms of hexavalent chromium by microorganisms. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111699. [PMID: 33396030 DOI: 10.1016/j.ecoenv.2020.111699] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/01/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
Extensive industrial activities have led to an increase of the content of chromium in the environment, which causes serious pollution to the surrounding water, soil and atmosphere. The enrichment of chromium in the environment through the food chain ultimately affects human health. Therefore, the remediation of chromium pollution is crucial to development of human society. A lot of scholars have paid attention to bioremediation technology owing to its environmentally friendly and low-cost. Previous reviews mostly involved pure culture of microorganisms and rarely discussed the optimization of bioreduction conditions. To make up for these shortcomings, we not only introduced in detail the conditions that affect microbial reduction but also innovatively introduced consortium which may be the cornerstone for future treatment of complex field environments. The aim of this study is to summary chromium toxicity, factors affecting microbial remediation, and methods for enhancing bioremediation. However, the actual application of bioremediation technology is still facing a major challenge. This study also put forward the current research problems and proposed future research directions, providing theoretical guidance and scientific basis for the application of bioremediation technology.
Collapse
Affiliation(s)
- Xue Tang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Yi Huang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China; State Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, Sichuan, China.
| | - Ying Li
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Li Wang
- State Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Xiangjun Pei
- State Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Dan Zhou
- State Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Peng He
- State Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Scott S Hughes
- Department of Geosciences, Idaho State University, Pocatello, ID 83209, USA
| |
Collapse
|
8
|
Wang D, Li G, Qin S, Tao W, Gong S, Wang J. Remediation of Cr(VI)-contaminated soil using combined chemical leaching and reduction techniques based on hexavalent chromium speciation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111734. [PMID: 33396063 DOI: 10.1016/j.ecoenv.2020.111734] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
Hexavalent chromium [Cr(VI)] has strong mobility and it can enter into deep regions of soil. Cr(VI)-contaminated soil remediation is the process of removing Cr(VI) present in deep soils and any residual Cr(VI). In this study, the Cr(VI)-contaminated soil in Chongqing was investigated, and the remediation and economic feasibility of chemical leaching and reduction combined with a soil repairing approach was explored. The results showed that the leaching reagent, liquid-solid ratio, leaching time, reduction agent dosage, reduction temperature and reduction time had significant (P < 0.05) effects on the remediation of Cr(VI). At 0.02 mol/L oxalic acid and citric acid using a liquid-solid ratio of 5:1 and leaching time of 45 min, the removal rate of Cr(VI) was 62.7%, the residual Cr(VI) in soil was 126 mg/kg, and the soil pH was 4.09 after leaching. Between 25 and 90 °C, and at a molar ratio of 25:1 of FeSO4•7 H2O to Cr(VI), the reduction rate of Cr(VI) in soil after reduction was 54.0-98.4%, and the leaching concentration of Cr(VI) in soil was 0.01-0.29 mg/L. The optimal reduction was at 90 °C for 60 min, resulting in only 2.7 mg/kg of residual Cr(VI) in soil. The cost of this technology to treat the area studied was 826 ¥/ton of soil, which represents an economically feasible method for Cr(VI)-contaminated soil remediation.
Collapse
Affiliation(s)
- Donghui Wang
- China Merchants Ecological Environmental Protection Technology Co., LTD, Chongqing 400067, China
| | - Guanghui Li
- China Merchants Ecological Environmental Protection Technology Co., LTD, Chongqing 400067, China.
| | - Shiqiang Qin
- China Merchants Ecological Environmental Protection Technology Co., LTD, Chongqing 400067, China
| | - Weiguang Tao
- China Merchants Ecological Environmental Protection Technology Co., LTD, Chongqing 400067, China
| | - Shihui Gong
- China Merchants Ecological Environmental Protection Technology Co., LTD, Chongqing 400067, China
| | - Jing Wang
- China Merchants Ecological Environmental Protection Technology Co., LTD, Chongqing 400067, China
| |
Collapse
|
9
|
Cd(II) adsorption from aqueous solutions using modified attapulgite. RESEARCH ON CHEMICAL INTERMEDIATES 2020. [DOI: 10.1007/s11164-020-04201-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
10
|
Lu J, Zhang B, He C, Borthwick AGL. The role of natural Fe(II)-bearing minerals in chemoautotrophic chromium (VI) bio-reduction in groundwater. JOURNAL OF HAZARDOUS MATERIALS 2020; 389:121911. [PMID: 31879105 DOI: 10.1016/j.jhazmat.2019.121911] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/04/2019] [Accepted: 12/15/2019] [Indexed: 06/10/2023]
Abstract
To date, comparatively little is known about the role of natural Fe(II)-bearing minerals in bioremediation of chromium (VI) contaminated aquifers subject to chemoautotrophic conditions. This work employed four kinds of Fe(II)-bearing minerals (pyrite, mackinawite, wustite, and magnetite) as inorganic electron donors to support Cr(VI) bio-reduction. In batch experiments, mackinawite (FeS) performed best, with Cr(VI) removal efficiency of 98.1 ± 1.21 % in 96 h. Continuous column experiments lasting 180 d implied that groundwater chemistry and hydrodynamics influenced the Cr(VI) removal process. A breakthrough study suggested that biotic and abiotic contributions to Cr(VI) reduction were 76.0 ± 1.12 % and 24.1 ± 1.43 %, respectively. Cr(VI) was reduced to insoluble Cr(III), whereas Fe(II) and S(-II) in mackinawite were finally oxidized to Fe(III) and sulfate. Mackinawite evolved progressively into pyrrhotite. High-throughput 16S rRNA gene sequencing indicated that mackinawite-driven Cr(VI) reduction was mediated through synergistic interactions of microbial consortia; i.e. autotrophs as Acidovorax synthesized volatile fatty acids as metabolic intermediates, which were consumed by Cr(VI) reducers as Geobacter. Genes encoding enzymes for S oxidation (soxB) and Cr(VI) reduction (chrA, yieF) were upregulated. Cytochrome c participating in Fe(II) oxidation increased significantly. This work advances the development of sustainable techniques for Cr(VI) polluted groundwater remediation.
Collapse
Affiliation(s)
- Jianping Lu
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China
| | - Baogang Zhang
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China.
| | - Chao He
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China
| | - Alistair G L Borthwick
- St Edmund Hall, Queen's Lane, Oxford, OX1 4AR, UK; School of Engineering, The University of Edinburgh, The King's Buildings, Edinburgh, EH9 3JL, UK
| |
Collapse
|
11
|
Recovery of Gold from the Refractory Gold Concentrate Using Microwave Assisted Leaching. METALS 2020. [DOI: 10.3390/met10050571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Microwave technology has been confirmed to be suitable for use in a wide range of mineral leaching processes. Compared to conventional leaching, microwave-assisted leaching has significant advantages. It is a proven process, because of its short processing time and reduced energy. The purpose of this study was to enhance the gold content in a refractory gold concentrate using microwave-assisted leaching. The leaching efficiencies of metal ions (As, Cu, Zn, Fe, and Pb) and recovery of gold from refractory gold concentrate were investigated via nitric acid leaching followed by microwave treatment. As the acid concentration increased, metal ion leaching increased. In the refractory gold concentrate leaching experiments, nitric acid leaching at high temperatures could limit the decomposition of sulfide minerals, because of the passive layer in the refractory gold concentrate. Microwave-assisted leaching experiments for gold recovery were conducted for the refractory gold concentrate. More extreme reaction conditions (nitric acid concentration > 1.0 M) facilitated the decomposition of passivation species derived from metal ion dissolution and the liberation of gangue minerals on the sulfide surface. The recovery rate of gold in the leach residue was improved with microwave-assisted leaching, with a gold recovery of ~132.55 g/t after 20 min of the leaching experiment (2.0 M nitric acid), according to fire assays.
Collapse
|
12
|
Hou S, Wu B, Peng D, Wang Z, Wang Y, Xu H. Remediation performance and mechanism of hexavalent chromium in alkaline soil using multi-layer loaded nano-zero-valent iron. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 252:553-561. [PMID: 31181500 DOI: 10.1016/j.envpol.2019.05.083] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/25/2019] [Accepted: 05/16/2019] [Indexed: 05/27/2023]
Abstract
Remediation of soil chromium (Cr) pollution is becoming more and more urgent. In this study, a multi-loaded nano-zero-valent iron (nZVI) material (CNH) was prepared by carboxymethyl cellulose (CMC) and humic acid (HA) as dispersant and support agent, respectively, and the remediation effect of CNH, HA and CN (CNH without HA) for Cr contaminated soil was investigated within 90 d cycle. After 7 d treatment of CNH, the HOAc-extractable Cr decreased significantly. After the 90 d remediation, the HOAc-extractable Cr decreased most in the treatment of 3% CNH, about 74.48% lower than control. All treatments eventually caused different decline of soil pH, with a range of 0.12-0.54, in which the CNH treatment group had the least depression. HA loading significantly weakened the toxicity of nZVI, resulting in the higher soil microbial quantity and enzyme activities compared with CN. Additionally, the improvement of soil microecology by CNH and HA was positively correlated with the ratio of application, while CN was negatively correlated (except FDA enzyme activity) with these indexes. These results emphasized the potential of the synthesized CNH as a promising material to remediate Cr contaminated soil. Furthermore, details of possible mechanistic insight into the Cr remediation were carefully discussed.
Collapse
Affiliation(s)
- Siyu Hou
- Key Laboratory of Bio-Resource and Eco-Evironment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, PR China
| | - Bin Wu
- Key Laboratory of Bio-Resource and Eco-Evironment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, PR China
| | - Dinghua Peng
- Key Laboratory of Bio-Resource and Eco-Evironment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, PR China
| | - Ziru Wang
- Key Laboratory of Bio-Resource and Eco-Evironment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, PR China
| | - Yiyang Wang
- Key Laboratory of Bio-Resource and Eco-Evironment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, PR China
| | - Heng Xu
- Key Laboratory of Bio-Resource and Eco-Evironment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, PR China.
| |
Collapse
|