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Wang Y, Wang C, Cheng C, Wu H, Liu H. Chromium removal at neutral pHs via electrochemical Cr(VI) reduction and subsequent Cr(III) adsorption with MoS 2 nanoflowers-modified graphite felt. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131582. [PMID: 37163895 DOI: 10.1016/j.jhazmat.2023.131582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 04/24/2023] [Accepted: 05/03/2023] [Indexed: 05/12/2023]
Abstract
The operation performance and stability of electrochemical Cr(VI) reduction are strongly restricted at neutral pHs (e.g., drinking water and groundwater) by the high Cr(VI) oxidation potentials and cathode passivation of Cr(OH)3 precipitates. Herein, we fabricated MoS2 nanoflowers-modified graphite felt (GF-MoS2) to construct the electrochemical apparatus (EA) and adsorption column (AC), attempting to stable and effective Cr(VI) removal at neutral pHs via electrochemical Cr(VI) reduction and subsequent Cr(III) adsorption. In EA with a sequential oxidation-reduction process, Cr(VI)-contaminated influent (5 mg/L) at neutral pHs (6.0-8.0) was oxidized first by anode to generate large amounts of H+ ions via H2O oxidation, decreasing the pH of anode-oxidized influent to ∼2.5 at 2.6 V and 1000 L/m2/h. Subsequently, the acidic anode-oxidized influent was further reduced by GF-MoS2 cathode, promoting significantly Cr(VI) reduction via decreasing Cr(VI) oxidation potentials and alleviating Cr(III) precipitation on cathode. These results enabled the stable and effective operation of GF-MoS2-based EA with almost Cr(VI) reduction to Cr(III). With further assembling GF-MoS2-based AC, Cr(III) species in EA effluent were easily adsorbed or intercepted by GF-MoS2, achieving undetectable Cr species in AC effluent. Combination techniques of GF-MoS2-based electrochemical reduction and adsorption can be an effective approach for remediating Cr(VI)-contaminated water at neutral pHs.
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Affiliation(s)
- Yang Wang
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, PR China
| | - Chenyang Wang
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, PR China
| | - Cheng Cheng
- College of Environmental and Ecology, Chongqing University, Chongqing 400045, PR China
| | - Haiming Wu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, PR China
| | - Hai Liu
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, PR China.
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Yang Y, Lu L, Shen Y, Wang J, Li L, Ma R, Ullah Z, Xiang M, Yu Y. Asymmetric Alternative Current Electrochemical Method Coupled with Amidoxime-Functionalized Carbon Felt Electrode for Fast and Efficient Removal of Hexavalent Chromium from Wastewater. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13050952. [PMID: 36903830 PMCID: PMC10005244 DOI: 10.3390/nano13050952] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/19/2023] [Accepted: 02/26/2023] [Indexed: 05/27/2023]
Abstract
A large amount of Cr (VI)-polluted wastewater produced in electroplating, dyeing and tanning industries seriously threatens water ecological security and human health. Due to the lack of high-performance electrodes and the coulomb repulsion between hexavalent chromium anion and cathode, the traditional DC-mediated electrochemical remediation technology possesses low Cr (VI) removal efficiency. Herein, by modifying commercial carbon felt (O-CF) with amidoxime groups, amidoxime-functionalized carbon felt electrodes (Ami-CF) with high adsorption affinity for Cr (VI) were prepared. Based on Ami-CF, an electrochemical flow-through system powered by asymmetric AC was constructed. The mechanism and influencing factors of efficient removal of Cr (VI) contaminated wastewater by an asymmetric AC electrochemical method coupling Ami-CF were studied. Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) characterization results showed that Ami-CF was successfully and uniformly loaded with amidoxime functional groups, and the adsorption capacity of Cr (VI) was more than 100 times higher than that of O-CF. In particular, the Coulomb repulsion effect and the side reaction of electrolytic water splitting were inhibited by the high-frequency anode and cathode switching (asymmetric AC), the mass transfer rate of Cr (VI) from electrode solution was increased, the reduction efficiency of Cr (VI) to Cr (III) was significantly promoted and a highly efficient removal of Cr (VI) was achieved. Under optimal operating conditions (positive bias 1 V, negative bias 2.5 V, duty ratio 20%, frequency 400 Hz, solution pH = 2), the asymmetric AC electrochemistry based on Ami-CF can achieve fast (30 s) and efficient removal (>99.11%) for 0.5-100 mg·L-1 Cr (VI) with a high flux of 300 L h-1 m-2. At the same time, the durability test verified the sustainability of the AC electrochemical method. For Cr (VI)-polluted wastewater with an initial concentration of 50 mg·L-1, the effluent concentration could still reach drinking water grade (<0.05 mg·L-1) after 10 cycling experiments. This study provides an innovative approach for the rapid, green and efficient removal of Cr (VI) containing wastewater at low and medium concentrations.
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Affiliation(s)
- Yunze Yang
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, School of Water and Environment, Chang’an University, Xi’an 710064, China
| | - Lun Lu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Yi Shen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Jun Wang
- State Key Laboratory of Separation Membranes and Membrane Processes, School of Environmental Science and Engineering, Tiangong University, Tianjin 300387, China
| | - Liangzhong Li
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Ruixue Ma
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Zahid Ullah
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Mingdeng Xiang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Yunjiang Yu
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, School of Water and Environment, Chang’an University, Xi’an 710064, China
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
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Ma W, Liu Y, Zhang S. Electrochemical reduction of Cr (VI) using a palladium/graphene modified stainless steel electrode. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:2184-2196. [PMID: 36378174 DOI: 10.2166/wst.2022.348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In this study, a palladium/graphene modified stainless steel electrode was successfully prepared and applied in an electrochemical reduction device to remove Cr (VI) from the wastewater. Pd was modified onto the electrode mainly via interacting with the carboxyl group of graphene. The Cr (VI) removal efficiency was up to 99.70 ± 0.00% under the optimal condition (Pd content proportion of 3%, electrode potential of -0.9 V, pH = 2 and electrolyte concentration of 6 g/L). It was found that Cr (VI) was removed via the following processes: (1) direct electrochemical reduction by accepting electrons, (2) indirect electrochemical reduction by H2O2 that was generated from H2 in the presence of Pd, (3) adsorption through hydrogen bond, and (4) chemical reduction through alkoxy groups donating electrons. The indirect electrochemical reduction considerably promoted the Cr (VI) removal while a small amount of Cr (VI) was removed via adsorption and chemical reduction. The method could not only be used as a pretreatment technology to solve the problem of excessive Cr (VI) concentration of industrial wastewater, but also could provide reference for the electrochemical reduction of similar metal ions.
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Affiliation(s)
- Wenqing Ma
- School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, PR China E-mail:
| | - Yubo Liu
- School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, PR China E-mail:
| | - Shaohui Zhang
- School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, PR China E-mail: ; Hubei Key Laboratory of Fuel Cell, Wuhan University of Technology, Wuhan 430070, PR China
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Li C, Zhu J, Zhao Z, Wang J, Yang Q, Sun H, Jiang B. An efficient and robust flow-through electrochemical Ti4O7 membrane system for simultaneous Cr(VI) reduction and Cr immobilization with membrane cleaning by a periodic polarity reversal strategy. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Koutavarapu R, Reddy CV, Syed K, Reddy KR, Saleh TA, Lee DY, Shim J, Aminabhavi TM. Novel Z-scheme binary zinc tungsten oxide/nickel ferrite nanohybrids for photocatalytic reduction of chromium (Cr (VI)), photoelectrochemical water splitting and degradation of toxic organic pollutants. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127044. [PMID: 34523469 DOI: 10.1016/j.jhazmat.2021.127044] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
A simple hydrothermal approach was demonstrated for synthesizing a coupled NiFe2O4-ZnWO4 nanocomposite, wherein one-dimensional ZnWO4 nanorods were inserted into two-dimensional NiFe2O4 nanoplates. Herein, we evaluated the photocatalytic removal of Cr(VI), and degradation of tetracycline (TC) and methylene blue (MB) by the nanocomposite, as well as its ability to split water. The ZnWO4 nanorods enriched the synergistic interactions, upgraded the solar light fascination proficiency, and demonstrated outstanding detachment and migration of the photogenerated charges, as confirmed by a transient photocurrent study and electrochemical impedance spectroscopy measurements. Compared to pristine NiFe2O4 and ZnWO4, the NiFe2O4-ZnWO4 nanocomposite exhibited a higher Cr(VI) reduction (93.5%) and removal of TC (97.9%) and MB (99.6%). Radical trapping results suggested that hydroxyl and superoxide species are dominant reactive species, thereby facilitating the Z-scheme mechanism. Furthermore, a probable photocatalytic mechanism was projected based on the experimental results. The photoelectrochemical analysis confirmed that NiFe2O4-ZnWO4 exhibited minor charge-transfer resistance and large photocurrents. We propose a novel and efficient approach for designing a coupled heterostructured nanocomposites with a significant solar light ability for ecological conservation and water splitting.
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Affiliation(s)
- Ravindranadh Koutavarapu
- Department of Robotics and Intelligent Machine Engineering, College of Mechanical and IT Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea
| | - Ch Venkata Reddy
- School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
| | - Kamaluddin Syed
- Department of Mechanical Engineering, Vignan's Institute of Information Technology, Visakhapatnam 530049, Andhra Pradesh, India
| | - Kakarla Raghava Reddy
- School of Chemical and Biomolecular Engineering, The University of Sydney, NSW 2006, Australia.
| | - Tawfik A Saleh
- Chemistry Department, King Fahd University of Petroleum & Minerals, B.O. Box: 346, Dhahran 31261, Saudi Arabia
| | - Dong-Yeon Lee
- Department of Robotics and Intelligent Machine Engineering, College of Mechanical and IT Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea
| | - Jaesool Shim
- School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
| | - Tejraj M Aminabhavi
- School of Advanced Sciences, KLE Technological University, Hubballi, Karnataka 580031, India.
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