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Wang C, Zhou S, Wang X, Tan W, Feng X. Photocatalytic activation of sulfite by maghemite (γ-Fe 2O 3) for iohexol degradation and alleviation effect of HCO 3- on water acidification. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 346:123557. [PMID: 38355082 DOI: 10.1016/j.envpol.2024.123557] [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: 12/08/2023] [Revised: 01/27/2024] [Accepted: 02/10/2024] [Indexed: 02/16/2024]
Abstract
Photo-catalyzing sulfite (S(IV)) for the generation of sulfate radical (SO4•-) has emerged as a novel advanced oxidation process (AOP) recently. However, both the potential of soil minerals as effective photocatalysts and the process of water acidification due to S(IV) oxidation have been overlooked. Herein, maghemite (γ-Fe2O3), a typical soil iron oxide with excellent photocatalytic reactivity like hematite and magnetic-collectible property like magnetite, was successfully used to activate S(IV) for iohexol degradation under visible light irradiation. As a result, 91.3% of iohexol was eliminated within 15 min at 0.1 g/L maghemite and 0.5 mM S(IV) under neutral conditions. The influencing factors, including initial pH, catalyst dosage, S(IV) amount, co-existing substances and water matrix, were systematically investigated. The maghemite/S(IV)/vis system exhibited superior performance in iohexol degradation at a wide pH range (3-10). It was found that the released proton via S(IV) oxidation led to severe water acidification. Interestingly, a low dose of HCO3- could evidently resist water acidification with little influence on iohexol elimination. Radical quenching experiments and electron spin resonance (ESR) analysis confirmed that SO4•-, •OH and •O2- were involved in iohexol abatement with SO4•- being the dominant reactive species. Compared with hydrogen peroxide, persulfate and peroxymonosulfate, the established maghemite/S(IV)/vis system achieved much more remarkable degradation performance. Furthermore, the reactivity of the catalyst was not obviously reduced even after 10 runs of reaction. This study expands the application of soil iron oxide mineral in S(IV) activation in water treatment and proposes an approach to regulate water acidification in S(IV)-based AOP.
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Affiliation(s)
- Cheng Wang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Shuijing Zhou
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Xiaoming Wang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Wenfeng Tan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Xionghan Feng
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.
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Zhang W, Li X, Zhao Y, Sun Z, Yao M, Zhou X, Li F, Ma F, Gu Q. Structural and mineralogical variation upon reoxidation of reduced Fe-bearing clay minerals during thermal activation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 902:166243. [PMID: 37595928 DOI: 10.1016/j.scitotenv.2023.166243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/03/2023] [Accepted: 08/10/2023] [Indexed: 08/20/2023]
Abstract
The hydroxyl radicals (OH) produced from Fe(II) oxidation upon reoxidation of reduced Fe-bearing clay minerals (RFC) have received increased attention and thermal activation was used to enhance Fe(II) oxidation to improve OH production. However, changes in mineral morphology and structure during thermally-activated RFC reoxidation are not yet clear. Herein, the Fe(II) oxidation extent was measured by chemical analysis during the reoxidation of model RFC (reduced nontronite (rNAu-2) at elevated temperatures. Mineralogical variation of rNAu-2 particles was observed by scanning electron microscopy (SEM), Mössbauer spectra, and X-ray photoelectron spectroscopy (XPS). The structural Fe(II) oxidation in rNAu-2 was accelerated with increasing temperature, accompanied by the transformation of structural entities and the dissolution of Fe and Si, while the overall structure of rNAu-2 minerals was relatively intact. The surface microstructure of particles showed the dissolved holes, net-shape flocs, and even large pore channels after Fe(II) oxidation by thermal activation. Moreover, the rearrangement of structural Fe(II) entities, the regeneration of edge Fe(II), and the electron transport from the interior to the edge were enhanced during rNAu-2 reoxidation by thermal activation. The increasing electron transfer at elevated temperatures could possibly be owing to the increasing number of reactive sites by increasing the internal disorder of rNAu-2. This work provides novel insights into the structural and mineralogical changes in promoting electron transfer upon RFC reoxidation.
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Affiliation(s)
- Wenwen Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiaodong Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yao Zhao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zongquan Sun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Meichen Yao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xuefei Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Fasheng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Fujun Ma
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Qingbao Gu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
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Xia Q, Chen J, Dong H. Effects of Organic Ligands on the Antibacterial Activity of Reduced Iron-Containing Clay Minerals: Higher Extracellular Hydroxyl Radical Production Yet Lower Bactericidal Activity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6888-6897. [PMID: 37083402 DOI: 10.1021/acs.est.3c00033] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Reduced iron-containing clay (RIC) minerals have been documented to exhibit antibacterial activity through a synergistic action of extracellular membrane attack and intracellular oxidation of cellular components. However, the relative importance between extracellular and intracellular processes has remained elusive. Here, metal-chelating organic ligands (lactate, oxalate, citrate, and ethylene diaminetetraacetic acid (EDTA)) were amended to the bactericidal assays such that the importance of the two processes could be evaluated. Reduced nontronite (rNAu-2) was used as a model clay mineral to produce extracellular hydroxyl radical (•OH) upon oxygenation. The presence of Fe-chelating ligands increased •OH yield by 3-5 times. Consequently, bacterial cell membrane attack was enhanced, yet the antibacterial activity of RIC diminished. Additional experiments revealed that the ligands inhibited soluble metal ions from adsorption onto the bacterial cell membrane and/or penetration into the cytoplasm. Consequently, intracellular Fe concentration for the ligand-treated group was nearly 2 orders of magnitude lower than that for no-ligand control, which greatly decreased intracellular accumulation of reactive oxygen species (ROS) and increased cell survival. These results highlight that destruction of intracellular contents (proteins and DNA) is more important than oxidative degradation of membrane lipids and cell envelope proteins in causing bacterial cell death by RIC.
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Affiliation(s)
- Qingyin Xia
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
| | - Jiubin Chen
- School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Hailiang Dong
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
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Cui HJ, Ning Y, Wu C, Peng W, Cheng D, Yin L, Zhou W, Liao W. Role of interfacial electron transfer reactions on sulfamethoxazole degradation by reduced nontronite activating H 2O 2. J Environ Sci (China) 2023; 124:688-698. [PMID: 36182174 DOI: 10.1016/j.jes.2022.02.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 06/16/2023]
Abstract
It has been documented that organic contaminants can be degraded by hydroxyl radicals (•OH) produced by the activation of H2O2 by Fe(II)-bearing clay. However, the interfacial electron transfer reactions between structural Fe(II) and H2O2 for •OH generation and its effects on contaminant remediation are unclear. In this study, we first investigated the relation between •OH generation sites and sulfamethoxazole (SMX) degradation by activating H2O2 using nontronite with different reduction extents. SMX (5.2-16.9 µmol/L) degradation first increased and then decreased with an increase in the reduction extent of nontronite from 22% to 62%, while the •OH production increased continually. Passivization treatment of edge sites and structural variation results revealed that interfacial electron transfer reactions between Fe(II) and H2O2 occur at both the edge and basal plane. The enhancement on basal plane interfacial electron transfer reactions in a high reduction extent rNAu-2 leads to the enhancement on utilization efficiencies of structural Fe(II) and H2O2 for •OH generation. However, the •OH produced at the basal planes is less efficient in oxidizing SMX than that of at edge sites. Oxidation of SMX could be sustainable in the H2O2/rNAu-2 system through chemically reduction. The results of this study show the importance role of •OH generation sites on antibiotic degradation and provide guidance and potential strategies for antibiotic degradation by Fe(II)-bearing clay minerals in H2O2-based treatments.
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Affiliation(s)
- Hao-Jie Cui
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Yaqi Ning
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Cong Wu
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Wei Peng
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Dong Cheng
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Lichu Yin
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Weijun Zhou
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Wenjuan Liao
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China.
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Fan Q, Wang L, Fu Y, Li Q, Liu Y, Wang Z, Zhu H. Iron redox cycling in layered clay minerals and its impact on contaminant dynamics: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 855:159003. [PMID: 36155041 DOI: 10.1016/j.scitotenv.2022.159003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/30/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
A majority of clay minerals contain Fe, and the redox cycling of Fe(III)/Fe(II) in clay minerals has been extensively studied as it may fuel the biogeochemical cycles of nutrients and govern the mobility, toxicity and bioavailability of a number of environmental contaminants. There are three types of Fe in clay minerals, including structural Fe sandwiched in the lattice of clays, Fe species in interlayer space and adsorbed on the external surface of clays. They exhibit distinct reactivity towards contaminants due to their differences in redox properties and accessibility to contaminant species. In natural environments, microbially driven Fe(III)/Fe(II) redox cycling in clay minerals is thought to be important, whereas reductants (e.g., dithionite and Fe(II)) or oxidants (e.g., peroxygens) are capable of enhancing the rates and extents of redox dynamics in engineered systems. Fe(III)-containing clay minerals can directly react with oxidizable pollutants (e.g., phenols and polycyclic aromatic hydrocarbons (PAHs)), whereas structural Fe(II) is able to react with reducible pollutants, such as nitrate, nitroaromatic compounds, chlorinated aliphatic compounds. Also structural Fe(II) can transfer electrons to oxygen (O2), peroxymonosulfate (PMS), or hydrogen peroxide (H2O2), yielding reactive radicals that can promote the oxidative transformation of contaminants. This review summarizes the recent discoveries on redox reactivity of Fe in clay minerals and its links to fates of environmental contaminants. The biological and chemical reduction mechanisms of Fe(III)-clay minerals, as well as the interaction mechanism between Fe(III) or Fe(II)-containing clay minerals and contaminants are elaborated. Some knowledge gaps are identified for better understanding and modelling of clay-associated contaminant behavior and effective design of remediation solutions.
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Affiliation(s)
- Qingya Fan
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Lingli Wang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yu Fu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Qingchao Li
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yunjiao Liu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Zhaohui Wang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; State Key Laboratory of Mineral Processing, Beijing 102628, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai 200062, China.
| | - Huaiyong Zhu
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4001, Australia
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Hu B, Zhang P, Liu H, Yuan S. Quantification of the Influence of Citrate/Fe(II) Molar Ratio on Hydroxyl Radical Production and Pollutant Degradation during Fe(II)-Catalyzed O 2 and H 2O 2 Oxidation Processes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:12977. [PMID: 36232278 PMCID: PMC9566542 DOI: 10.3390/ijerph191912977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/07/2022] [Accepted: 10/08/2022] [Indexed: 05/30/2023]
Abstract
Ligand-enhanced hydroxyl radical (•OH) production is an important strategy for Fe(II)-catalyzed O2 and H2O2 oxidation processes. However, the influence of the molar ratio of ligands to Fe(II) on •OH production remains elusive. This study employed citrate and inorganic dissolved Fe(II) (Fe(II)dis) as the representative ligand and Fe(II) species, respectively, to quantify this relationship. Results showed that •OH production was highly dependent on the citrate/Fe(II) molar ratio. For instance, for the oxygenation of Fe(II)dis, the •OH accumulations were 2.0-8.5, 3.4-28.5 and 8.1-42.3 μM at low (0.25-0.5), moderate (0.5-1), and high (1-2) citrate/Fe(II) molar ratios, respectively. At low citrate/Fe(II) molar ratio (<0.5), inorganic Fe(II)dis mainly contributed to •OH production, with the increase in the citrate/Fe(II) molar ratio to a high level (1-2), Fe(II)-citrate complex turned to the electron source for •OH production. The change in Fe(II) speciation with the increase of citrate/Fe(II) molar ratio elevated •OH production. For pollutant degradation, 1 mg/L phenol was degraded by 53.6% within 40 min during oxygenation of Fe(II)-citrate system (1:1) at pH 7. Our results suggest that a moderate molar ratio of ligand/Fe(II) (0.5-1) may be optimal for Fe(II)-catalyzed O2 and H2O2 oxidation processes.
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Affiliation(s)
- Bingbing Hu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, China
| | - Peng Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, China
| | - Hui Liu
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, China
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He P, Xiong Y, Chen Y, Liu M, Zhu J, Gan M. One-step synthesis of natural montmorillonite/hematite composites with enhanced persulfate catalytic activity for sulfamethoxazole degradation: Efficiency, kinetics, and mechanism. ENVIRONMENTAL RESEARCH 2022; 204:112326. [PMID: 34748776 DOI: 10.1016/j.envres.2021.112326] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/24/2021] [Accepted: 10/30/2021] [Indexed: 06/13/2023]
Abstract
Along with rapid development of sulfate radicals-based advanced oxidation process, efficient, alternatively eco-friendly and cost-effective catalyst is of uppermost priority. However, expensive chemicals are used as source of metal in most of these catalysts, and lose sight of the abundant natural mineral resources on immediate surroundings. In this work, montmorillonite and hematite, two of abundantly natural minerals were utilized to prepare a persulfate catalyst (TMH@M) for sulfamethoxazole (SMX) degradation. The results indicated more than 91% of SMX was removed within 60 min in TMH@M/PS system. The degradation efficiency of SMX of TMH@M/PS combined system was impacted by SMX concentration, PS dosage and natural organic matters, and can remain stable in a certain concentration of HA/chelating agent and a wide pH range (3.01-9.06). Radical scavenging and EPR tests demonstrated 1O2, OH, and SO4- were major reactive oxygen species in the TMH@M/PS system, while the latter seems more important for degradation of SMX. The results of SEM-EDS, XRD and XPS conformed that low valence iron species (Fe0, Fe2+ and Fe3O4) on TMH@M surface are the main driving force behind PS activation to generate reactive species. Furthermore, the iron species on TMH@M surface were transformed during reaction, that in favor of mitigating metal leaching. This work presented a method based on ubiquitous natural minerals to prepare catalyst with excellent PS activate performance for organic wastewater treatment implying a new strategy in minerals utilization deeply and a promisingly alternative process for organic wastewater treatment based on mineral materials.
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Affiliation(s)
- Peng He
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Yao Xiong
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Yaozong Chen
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Mengfei Liu
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Jianyu Zhu
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
| | - Min Gan
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
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Zhou Z, Zeng Q, Li G, Hu D, Xia Q, Dong H. Oxidative degradation of commingled trichloroethylene and 1,4-dioxane by hydroxyl radicals produced upon oxygenation of a reduced clay mineral. CHEMOSPHERE 2022; 290:133265. [PMID: 34914951 DOI: 10.1016/j.chemosphere.2021.133265] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/07/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
Improper disposal of chlorinated solvents such as trichloroethylene (TCE) and its stabilizer 1,4-dioxane has resulted in extensive contamination in soils and groundwater. Oxidative degradation of these contaminants by strong oxidants has been proposed recently as a remediation strategy, but specific mechanisms and degradation efficiencies are still poorly understood, especially in commingled systems. In this study, a reduced iron-bearing clay (RIC), nontronite (rNAu-2), was oxygenated to produce hydroxyl radicals (•OH) for degradation of TCE and 1,4-dioxane under circumneutral and dark conditions. Results showed that TCE and 1,4-dioxane could be effectively degraded during oxygenation of rNAu-2 in both single and commingled systems. Compared with the single compound system, the degradation rates and efficiencies of TCE and 1,4-dioxane decreased in the commingled system. The negative effect was more significant for TCE than 1,4-dioxane. The commingled TCE and 1,4-dioxane impacted the degradation pattern of each other, due to their difference in •OH scavenging efficiency, surface affinity to rNAu-2 and solubility. Moreover, solution pH, buffer type, rNAu-2 dosage, and dissolved organic matter all affected •OH production and contaminant degradation efficiency. Our findings provide new insights for investigating the natural attenuation of commingled chlorinated solvents and 1,4-dioxane by RIC in redox-fluctuating environments and offer guidance for developing possible in-situ remediation strategies.
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Affiliation(s)
- Ziqi Zhou
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China
| | - Qiang Zeng
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China.
| | - Gaoyuan Li
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; Institute of Earth Sciences, China University of Geosciences, Beijing, 100083, China
| | - Dafu Hu
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China
| | - Qingyin Xia
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China
| | - Hailiang Dong
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China.
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9
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Chen S, Yang Y, Jing X, Zhang L, Chen J, Rensing C, Luan T, Zhou S. Enhanced aging of polystyrene microplastics in sediments under alternating anoxic-oxic conditions. WATER RESEARCH 2021; 207:117782. [PMID: 34731659 DOI: 10.1016/j.watres.2021.117782] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 09/29/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Aging of microplastics (MPs) (i.e., degradation and weathering) is ubiquitous in the environment. The MP aging process is thought to be limited to light and static areas, while aging in dark and fluctuating anoxic-oxic areas is poorly understood. Here, we provide initial evidence for aging of polystyrene microplastics (PS-MPs) under different anoxic/oxic conditions in sediments, and we further explored these mechanisms using sediment column experiments and pure-culture experiments. The results showed that PS-MPs in alternating anoxic-oxic sediments displayed the highest degree of aging. In the in-situ experiment, both the weight losses and O/C ratios of PS-MPs aged under alternating anoxic-oxic conditions were ∼2 times higher than those aged under static oxic and static anoxic conditions during 2-month experiments. In a 2-month column experiment, the PS-MPs in the alternating anoxic-oxic group showed weight losses and O/C ratios that were, respectively, triple and double the corresponding values for the static oxic and static anoxic groups. Column and pure-culture experiments demonstrated that dark production of ·OH which showed a positive correlation with a Fe redox process could explain enhanced MP aging under the alternating anoxic-oxic conditions. These findings provide a basis for risk assessment and management of MPs in the natural environment, such as in intertidal zones and paddy fields, and also have implications for engineering of optimized MP degradation processes.
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Affiliation(s)
- Shanshan Chen
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuting Yang
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xianyue Jing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lanlan Zhang
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Jin Chen
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Christopher Rensing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Tiangang Luan
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Shungui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Guo D, Xia Q, Zeng Q, Wang X, Dong H. Antibacterial Mechanisms of Reduced Iron-Containing Smectite-Illite Clay Minerals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15256-15265. [PMID: 34723508 DOI: 10.1021/acs.est.1c04367] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Reduced nontronite has been demonstrated to be antibacterial through the production of hydroxyl radical (•OH) from the oxidation of structural Fe(II). Herein, we investigated the antibacterial activity of more common smectite-illite (S-I) clays toward Escherichia coli cells, including montmorillonite SWy-3, illite IMt-2, 50-50 S-I rectorite RAr-1, 30-70 S-I ISCz-1, and nontronite NAu-2. Under an oxic condition, reduced clays (with a prefix r before mineral names) produced reactive oxygen species (ROS), and the antibacterial activity followed the order of rRAr-1 > rSWy-3 ≥ rNAu-2 ≫ rIMt-2 ≥ rISCz-1. The strongest antibacterial activity of rRAr-1 was contributed by a combination of •OH and Fe(IV) generated from structural Fe(II)/adsorbed Fe2+ and soluble Fe2+, respectively. Higher levels of lipid and protein oxidation, intracellular ROS accumulation, and membrane disruption were consistent with this antibacterial mechanism of rRAr-1. The antibacterial activity of other S-I clays depended on layer expandability, which determined the reactivity of structural Fe(II) and the production of •OH, with the expandable smectite being the most antibacterial and nonexpandable illite the least. Our results provide new insights into the antibacterial mechanisms of clay minerals.
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Affiliation(s)
- Dongyi Guo
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, P.R. China
| | - Qingyin Xia
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, P.R. China
| | - Qiang Zeng
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, P.R. China
| | - Xi Wang
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, P.R. China
| | - Hailiang Dong
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, P.R. China
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Yang R, Cai J, Yang H. Enhanced reactivity of zero-valent aluminum/O 2 by using Fe-bearing clays in 4-chlorophenol oxidation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 773:145661. [PMID: 33940749 DOI: 10.1016/j.scitotenv.2021.145661] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/08/2021] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Zero-valent aluminum (ZVAl) is a promising reductant because of its relatively low redox potential, which can efficiently activate molecular oxygen to generate reactive oxygen species. However, its long-term performance is limited by the intrinsic dense oxide layer and the passivation effect of the accumulative Al-(hydr)oxide on its surface during the reaction. In this study, four clay minerals with different compositions were mixed with ZVAl by ball milling to obtain four composites of ZVAl and clay (ZVAl-Clay), which were used to degrade a high concentration of 4-chlorophenol (4-CP) under ambient conditions. The oxidation efficiencies of different ZVAl-Clays were strongly relevant to Fe contained in the clay minerals. The Fe-free ZVAl-Clay presented poor oxidation performance, whereas the reaction efficiencies of those ZVAl composites with Fe-bearing clays exhibited varying degrees of improvement. In comparison with the original ZVAl, the highest oxidation rate increased by 23 times, the maximum increased OH production was approximately 8 times, and the corresponding mineralization efficiency improved by 38.7%. However, the levels of improved oxidation performance of various ZVAl-Clays were not positively correlated with their actual total Fe contents, and their degradation efficiencies might also be affected by other physical and/or chemical properties of different clays. The synergistic mechanism revealed by various characterizations was that electron transfer might occur from ZVAl to the structural Fe(III) of the clay through the basal plane or edge of clays triggered by ball milling. Thus, the partially produced Fe(II) on the clay surface promoted the Fenton-like reaction to decompose H2O2 into OH for efficient oxidation of 4-CP. In short, the ZVAl composites with Fe-bearing clays deserved further exploration as potential materials for efficient degradation of organic matters in wastewater samples.
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Affiliation(s)
- Ran Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Jun Cai
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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Yu H, Liu G, Jin R, Zhou J. Goethite-humic acid coprecipitate mediated Fenton-like degradation of sulfanilamide: The role of coprecipitated humic acid in accelerating Fe(III)/Fe(II) cycle and degradation efficiency. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:124026. [PMID: 33265047 DOI: 10.1016/j.jhazmat.2020.124026] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 06/12/2023]
Abstract
While extensive studies found that dissociative and iron mineral-adsorbed humic acid (HA) could either stimulate or inhibit Fenton-like processes, little was known about the influence of iron mineral-coprecipitated HA on Fenton-like reactions. Here, goethite and HA (Gt-HA) coprecipitates having different C:Fe molar ratios (C:Fe = 0.16-0.99) were biologically prepared, and for the first time, investigated for their abilities of H2O2 activation and catalytic degradation of sulfanilamide. For system containing Gt-HA with the optimal C:Fe ratio of 0.30, over 91.1% of sulfanilamide (10 mg/L) was removed in 2 h, which was 46.2% higher than that of the control Gt system. Additionally, H2O2 decomposition, •OH production, and organic carbon removal in Gt-HA systems were all more efficient than those in Gt system. Higher carbon moieties stability and lower micropore surface area of Gt-HA decreased the competition for •OH and H2O2, thus helped to improve degradation efficiency. Electrochemical analysis, quenching experiments, and Fe species detection showed that the coprecipitated HA could serve as electron shuttle and complex with Fe(III) mainly via carboxyl groups at octahedral sites to improve Fe(III)/Fe(II) transformation. This study improved our understanding of Fe(III)/Fe(II) cycling in Fe‒C coprecipitates and demonstrated the potential of developing Fe‒C coprecipitates as efficient catalysts in Fenton-like processes.
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Affiliation(s)
- Huali Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Guangfei Liu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | - Ruofei Jin
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jiti Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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Synergistic effect of Co(II) doping on FeS activating heterogeneous Fenton processes toward degradation of Rhodamine B. CHEMICAL ENGINEERING JOURNAL ADVANCES 2020. [DOI: 10.1016/j.ceja.2020.100044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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