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Zhou Y, Peng H, Jiang L, Wang X, Tang Y, Xiao L. Control of cyanobacterial bloom and purification of bloom-laden water by sequential electro-oxidation and electro-oxidation-coagulation. JOURNAL OF HAZARDOUS MATERIALS 2024; 462:132729. [PMID: 37839377 DOI: 10.1016/j.jhazmat.2023.132729] [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: 06/21/2023] [Revised: 09/11/2023] [Accepted: 10/05/2023] [Indexed: 10/17/2023]
Abstract
The outbreaks of cyanobacterial blooms have caused severe threat to aquatic ecosystem and public health. In this work, electrochemical technology with RuO2/IrO2/Ti (RIT) or/and Al as anode for cyanobacterial bloom control and simultaneous water purification were studied. Compared with RIT-Al and Al electrodes, RIT exhibited the highest effects on bloom algae inactivation and inhibition of algae regrowth. Live/dead analysis, SEM, intracellular reactive oxygen species (ROS) and antioxidant system activities revealed that RIT could disintegrate bloom flocs and damage embedded algal cells due to high intensity of oxidation. With the lysis of cyanobacterial bloom, high content of intracellular compounds containing organic carbon, nitrogen and phosphorus released, necessitating water quality restoration. In the subsequent water purification process, RIT-Al overtook RIT and Al in removal of organic and nutrient pollutants due to the complex effects of electro-oxidation, coagulation, co-precipitation, electro-nitrification and electro-denitrification. Therefore, sequential electro-oxidation and electro-oxidation-coagulation process was an effective method for control cyanobacteria bloom and simultaneous removal of DOM, microcystin-LR (MC-LR), nitrogen and phosphorus, which is a promising technology.
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Affiliation(s)
- Yingping Zhou
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Huijun Peng
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Lijuan Jiang
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Xiaolin Wang
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Yuqiong Tang
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Lin Xiao
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China.
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Lu J, Zhang P, Li J, Cao Y, Zhang W, Zhang X, Yi X, Wang H. Mo(VI) removal from water by aluminum electrocoagulation: Cost-effectiveness analysis, main influencing factors, and proposed mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132608. [PMID: 37748311 DOI: 10.1016/j.jhazmat.2023.132608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/27/2023]
Abstract
Mo(VI) (MoO42-) removal by aluminum electrocoagulation (Al EC) with Al as anodes and cathodes was studied for the first time. At the initial Mo concentrations of 0.3 - 150 mg/L, kinetic analysis and effects of main factors (electrode connection modes, current density (CD), initial pH, and electrolytes) were examined, and potential mechanism of Mo(VI) removal were elucidated. Results showed that CD had significant impacts on anode weight loss, cathode weight loss, and total electrode weight loss (p value < 0.05). Cathode weight loss was higher than anode weight loss. XRD analysis results showed lower crystallinity of scums than that of precipitates. Boehmite was the most prevalent oxide in scums. An appropriate amount of NaCl was beneficial for enhancing the Mo(VI) removal efficiency and reducing the energy consumption of the Al EC process. Electrostatic attraction, surface complexation, hydroxyl exchange, flocculation, and coprecipitation were the main mechanisms involved in the Mo(VI) removal process by Al EC. Al EC outperformed conventional chemical coagulation in terms of Mo(VI) removal at the same dosage of Al. The Mo(VI) removal efficiencies in two real water samples (lake water and river water) reached up to 89.2% and 71.2%, respectively. This study provides novel insights into the strategies for the removal of oxoanionic metal pollutants and reduction of operating cost by Al EC technology.
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Affiliation(s)
- Jianbo Lu
- School of Civil Engineering, Yantai University, Yantai 264005, Shandong, China.
| | - Peng Zhang
- School of Civil Engineering, Yantai University, Yantai 264005, Shandong, China
| | - Jie Li
- School of Economics and Management, Yantai University, Yantai 264005, Shandong, China
| | - Yumin Cao
- School of Civil Engineering, Yantai University, Yantai 264005, Shandong, China
| | - Wei Zhang
- School of Civil Engineering, Yantai University, Yantai 264005, Shandong, China
| | - Xintong Zhang
- School of Civil Engineering, Yantai University, Yantai 264005, Shandong, China
| | - Xuesong Yi
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou 570228, China
| | - Hongjie Wang
- School of Eco-Environment, Hebei University, Baoding 071002, Hebei, China
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Li H, He Y, Yan Z, Yang Z, Tian F, Liu X, Wu Z. Insight into the microbial mechanisms for the improvement of spent mushroom substrate composting efficiency driven by phosphate-solubilizing Bacillus subtilis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 336:117561. [PMID: 36868154 DOI: 10.1016/j.jenvman.2023.117561] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/19/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
The objective of this study was to investigate the microbial mechanisms for the improvement of composting efficiency after Bacillus subtilis inoculation with soluble phosphorus function in the spent mushroom substrate (SMS) aerobic composting. The methods in this study, including redundant analysis (RDA), co-occurrence network analyze and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt 2) were carried out studying the dynamic changes of phosphorus (P) components, microbial interactions and metabolic characteristics in the SMS aerobic composting inoculated with phosphorus-solubilizing B. subtilis (PSB). An increase in germination index (GI) (up to 88.4%), total nitrogen (TN) (16.6 g kg-1), available P content (0.34 g kg-1) and total P (TP) content (3.20 g kg-1) and a decrease in total organic carbon (TOC), C/N and electrical conductivity (EC) in final composting stage indicated B. subtilis inoculation could further improve maturity quality of the composting product compared with CK. Other results also demonstrated that PSB inoculation increased the stability of compost, humification degree and bacterial diversity, contributing to P fractions transformation in the composting process. Co-occurrence analysis suggested that PSB strengthened microbial interactions. Metabolic function of bacterial community analysis showed pathways such as carbohydrate metabolism, and amino acid metabolism in the composting were increased by effects of PSB inoculation. In summary, this study reveals a useful basis for better regulating the P nutrient level of the SMS composting and reducing environmental risks by inoculating B. subtilis with P solubilizing function.
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Affiliation(s)
- Haijie Li
- School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Xi'an Polytechnic University, Xi'an, 710048, PR China
| | - Yanhui He
- School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Xi'an Polytechnic University, Xi'an, 710048, PR China
| | - Zhuo Yan
- School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Xi'an Polytechnic University, Xi'an, 710048, PR China
| | - Zihe Yang
- School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Xi'an Polytechnic University, Xi'an, 710048, PR China
| | - Fei Tian
- School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Xi'an Polytechnic University, Xi'an, 710048, PR China
| | - Xiaocheng Liu
- School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Xi'an Polytechnic University, Xi'an, 710048, PR China
| | - Zhansheng Wu
- School of Environmental and Chemical Engineering, Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries, Xi'an Polytechnic University, Xi'an, 710048, PR China.
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Jiang C, Liu Y, Zhang C, Li X. Study on influencing parameters and long-term operation of electrocoagulation phosphorus removal from small rural domestic sewage. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2023; 87:1866-1878. [PMID: 37119160 DOI: 10.2166/wst.2023.112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Excessive discharge of phosphorus can produce eutrophication in aquatic environments, damaging public health, the living environment, and the economy. The conventional mechanical-biological phosphorus removal methods are not suitable for small rural domestic sewage due to the features of small scale, scattered distribution, intermittent emission, and large fluctuation. This work evaluated electrocoagulation (EC) with industrial steel as electrodes on small rural domestic sewage. Results showed that the best performance was achieved at a current density of 1 mA/cm2, electrode distance of 2 cm, electrode number of 2, pH of 7, and Hydraulic Retention Time of 30 min, respectively. Under optimum conditions, the EC process removed 93.91% phosphorus while consuming around 0.25 kWh/m3 of electricity. In addition, the electrode passivation of EC was further investigated; the long-term research found that the phosphorus removal efficiency only decreased by 4.34% after 10 days of continuous flow operation, and the operational energy consumption was 0.07 kWh/m3 at a Cl- concentration of 500 mg/L.
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Affiliation(s)
- Chunfeng Jiang
- School of Energy and Environment, Southeast University, Nanjing 210096, China E-mail:
| | - Yanqing Liu
- School of Energy and Environment, Southeast University, Nanjing 210096, China E-mail:
| | - Chong Zhang
- School of Energy and Environment, Southeast University, Nanjing 210096, China E-mail:
| | - Xianning Li
- School of Energy and Environment, Southeast University, Nanjing 210096, China E-mail:
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Lu J, Wang L, Si G, Lu B, Zhang X, Li J, Zhang W, Wang Z. Tertiary treatment of bio-treated landfill leachate by a two-step electrochemical process including electrooxidation and electrocoagulation: a bench-scale trial. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:32600-32613. [PMID: 36464744 DOI: 10.1007/s11356-022-24028-y] [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: 06/23/2022] [Accepted: 11/01/2022] [Indexed: 06/17/2023]
Abstract
A two-step electrochemical process including electrooxidation (EO) and electrocoagulation (EC) was proposed for the tertiary treatment of bio-treated landfill leachate (BTLL). The operating conditions of sole EO and EC technology were optimized via batch tests. Batch tests indicate that EO displayed superior removal efficiency towards color (89%) and UV254 (64%) under optimal experimental conditions. EC with the electrode combinations Fe-Fe-Fe-Fe (four plates, anode-cathode-anode-cathode) performed better than the other electrode combinations (Fe-Al-Fe-Al, Al-Fe-Al-Fe, Al-Al-Al-Al) and showed excellent removal efficiency towards COD (60%) and color (85%). In continuous-flow tests of 13 h, compared to sequential EC-EO process, the sequential EO-EC process was more effective than the sequential EC-EO process in reducing organic matters (COD, TOC) and residual chlorine. The sequential EO-EC process could remove 50% COD, 55% TOC, 72% UV254, and 96% color. The average concentration of residual chlorine in the final effluent of EO-EC process (147 mg/L) was significantly lower than that of EC-EO process (463 mg/L). UV-vis and GC-MS analyses indicate that the BTLL mainly contained humic acid and fulvic acid-like substances with unsaturated bonds. Conjugated unsaturated organics could be degraded into organic of small molecular weight after the sequential EO-EC process. EEM spectroscopic analysis revealed that soluble microbial byproducts became the predominant organics in the final effluent. This work verifies the synergism between EO and EC and provides some insights into the removal and degradation performance of organic substances in BTLL during the sequential EO-EC treatment.
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Affiliation(s)
- Jianbo Lu
- School of Civil Engineering, Yantai University, No.30, Qingquan Road, Laishan District, Shandong Province, 264005, Yantai, China
| | - Lei Wang
- School of Civil Engineering, Yantai University, No.30, Qingquan Road, Laishan District, Shandong Province, 264005, Yantai, China
| | - Guifang Si
- School of Civil Engineering, Yantai University, No.30, Qingquan Road, Laishan District, Shandong Province, 264005, Yantai, China
| | - Bin Lu
- Shanghai Municipal Engineering Design Institute (Group) Co., Ltd, Shanghai, 200092, China
| | - Xintong Zhang
- School of Civil Engineering, Yantai University, No.30, Qingquan Road, Laishan District, Shandong Province, 264005, Yantai, China.
| | - Jie Li
- School of Economics and Management, Yantai, 264005, Shandong Province, China
| | - Wei Zhang
- School of Civil Engineering, Yantai University, No.30, Qingquan Road, Laishan District, Shandong Province, 264005, Yantai, China
| | - Zhenhua Wang
- School of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, Shandong Province, China
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Lu Z, Zhang K, Liu F, Gao X, Zhai Z, Li J, Du L. Simultaneous recovery of ammonium and phosphate from aqueous solutions using Mg/Fe modified NaY zeolite: Integration between adsorption and struvite precipitation. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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7
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Removal of phosphate in secondary effluent from municipal wastewater treatment plant by iron and aluminum electrocoagulation: Efficiency and mechanism. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.120439] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Liu L, Zheng X, Wei X, Kai Z, Xu Y. Excessive application of chemical fertilizer and organophosphorus pesticides induced total phosphorus loss from planting causing surface water eutrophication. Sci Rep 2021; 11:23015. [PMID: 34837009 PMCID: PMC8626514 DOI: 10.1038/s41598-021-02521-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/16/2021] [Indexed: 11/09/2022] Open
Abstract
Total phosphorus (TP) loss from planting was one of the resources causing agricultural non-point source pollution. It is significant to clarify the factors influencing TP loss, as well as explore the relationship between TP loss from planting and surface water eutrophication for making recommendations on the reduction of environmental pollution. In this study, the minimum and maximum of average TP loss was appeared in Qinghai and Shandong province with the TP loss of 7.7 × 102 t and 7.5 × 103 t from 2012 to 2014, respectively. The results of structural equation model (SEM) indicating that the effect of anthropogenic drivers on TP loss was more important than natural conditions due to the higher path coefficient of anthropogenic drivers (0.814) than that of natural conditions (0.130). For anthropogenic drivers, the path coefficients of usage of fertilizer and pesticides, which was often excessively applied in China, were 0.921 and 0.909, respectively causing they the two dominant factors affecting TP loss. Annual precipitation and relative humidity, which were belongs to natural conditions, increased TP loss by enhancing leaching and surface runoff. However, light duration could reduce TP loss by promoting crop growth and increasing TP absorption of crops, with a path coefficient of - 0.920. TP loss of each province in per unit area from planting was significantly correlated with TP concentration of its surface water (p < 0.05), suggesting that TP loss from planting was the main factor causing surface water eutrophication. This study targeted presented three proposals to reduce the TP loss from planting, including promotion of scientific fertilization technologies, restriction of organophosphorus pesticides, and popularization of water saving irrigation technologies. These findings as well as suggestions herein would provide direction for the reduction of TP loss from planting.
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Affiliation(s)
- Liyuan Liu
- Institute of Plant Nutrition, Resources and Environment, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100089, China
| | - Xiangqun Zheng
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China
| | - Xiaocheng Wei
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China
| | - Zhang Kai
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China
| | - Yan Xu
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China.
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Wei Y, Wang J, Chang R, Zhan Y, Wei D, Zhang L, Chen Q. Composting with biochar or woody peat addition reduces phosphorus bioavailability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:142841. [PMID: 33077217 DOI: 10.1016/j.scitotenv.2020.142841] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 09/23/2020] [Accepted: 10/03/2020] [Indexed: 05/22/2023]
Abstract
Biochar and woody peat have been recognized as an additive to reduce carbon and nitrogen loss during composting. Yet little is known about their influences on the transformation of phosphorus (P) fractions in composting. This study investigated the quantitative and qualitative changes in different P forms during composting with adding biochar or woody peat using sequential extraction and P K-edge X-ray absorption near-edge structure (XANES). The results showed that compost products from the treatment with adding woody peat had a higher HA/FA (the ratio of humic acid to fulvic acid) compared to biochar treatment and the control, suggesting that the addition of woody peat might benefit the humification process of composting. Sequential extraction and XANES illustrated that adding biochar or woody peat limited the P availability. Biochar increased the proportion of Pi and woody peat decreased the conversion from Po to Pi compared to the control. Structural equation modeling and redundancy analysis suggested that biochar improved the refractory P based on the indirect effects of NH4+-N by regulating microbial community, while woody peat was beneficial for Po accumulation by affecting humic acid. Taken together, this research provides basis for regulating the nutrient level of carbon, nitrogen, and phosphorus in composts and reducing environmental risks.
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Affiliation(s)
- Yuquan Wei
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resource and Environmental Sciences, China Agricultural University, Beijing 100193, China; Organic Recycling Institute (Suzhou) of China Agricultural University, Wuzhong District, Suzhou 215128, China
| | - Jue Wang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resource and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Ruixue Chang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resource and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Yabin Zhan
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resource and Environmental Sciences, China Agricultural University, Beijing 100193, China; Organic Recycling Institute (Suzhou) of China Agricultural University, Wuzhong District, Suzhou 215128, China
| | - Dan Wei
- Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Lei Zhang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resource and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Qing Chen
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resource and Environmental Sciences, China Agricultural University, Beijing 100193, China.
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Wang S, Ma C, Zhu Y, Yang Y, Du G, Li J. Deep dewatering process of sludge by chemical conditioning and its potential influence on wastewater treatment plants. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:33838-33846. [PMID: 29905896 DOI: 10.1007/s11356-018-2351-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
FeCl3, quick lime, and cationic polyacrylamide (CPAM) were used for excess sludge conditioning from wastewater treatment plant (WWTP) and the dewatering performance by different chemical conditioners was investigated. Experimental results showed that FeCl3 could make small and concentrated sludge particles. Furthermore, new mineral phase structures for building a dewatering framework were obtained by the addition of quick lime, and the coagulation capacity was enhanced by the formation of colloid hydroxyl polymer, which was induced due to the alkaline environment. In addition, the floc particle size significantly increased after the CPAM dosage. The bound water could be released with the stripping of tightly bound extracellular polymeric substance (EPS). Therefore, the dewatering performance and efficiencies were improved and subsequently the hypothetical sludge deep dewatering process was depicted in accordance with the variation of EPS. However, high-strength refractory organics in sludge filtrates caused by quick lime pyrolysis could lead to the unstable operation of the WWTP, because the relatively high concentrations of organic compounds with benzene were dominant in sludge dewatering filtrates.
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Affiliation(s)
- Shuo Wang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China
| | - Cong Ma
- State Key Laboratory of Separation Membranes and Membrane Processes, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin, 300387, China.
| | - Yin Zhu
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Yangkun Yang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- Ministry Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Ji Li
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China.
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China.
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Liang S, Zheng W, Zhu L, Duan W, Wei C, Feng C. One-Step Treatment of Phosphite-Laden Wastewater: A Single Electrochemical Reactor Integrating Superoxide Radical-Induced Oxidation and Electrocoagulation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5328-5336. [PMID: 30998005 DOI: 10.1021/acs.est.9b00841] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Elimination of phosphite from water is more difficult than elimination of phosphate owing to its higher solubility and resistance to biotransformation. Herein, we report an efficient, facile, electrochemical method integrating electrooxdiation (EO) and electrocoagulation (EC) to treat phosphite-laden wastewater. The mechanistic studies demonstrate that in-situ-generated Fe2+ at an Fe anode can react with in-situ-generated O2 at a mixed metal oxide (MMO) anode, leading to formation of •O2-, a reactive species predominantly responsible for oxidation of phosphite to phosphate. The phosphate is immediately coagulated by Fe hydroxides that are formed due to the production of OH- at a stainless-steel cathode. The integrated EO/EC system enables a phosphite removal efficiency of 74.25% (MMO anode, 100 mA; Fe anode, 100 mA; reaction time, 60 min), a significantly higher efficiency rate than the rate obtained in the control experiments in the absence of an MMO anode (<23.41%) and the rate obtained with the chemical coagulation process (<5.03%). The quenching experiments with scavengers and electron spin resonance tests verify the pivotal role of •O2- in transformation of phosphite. Tests carried out with nickel-plating wastewater further demonstrate the superiority of this integrated system, as evidenced by efficient removal of phosphite and nickel from the solution.
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Affiliation(s)
- Sheng Liang
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy , South China University of Technology , Guangzhou 510006 , People's Republic of China
| | - Wenxiao Zheng
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy , South China University of Technology , Guangzhou 510006 , People's Republic of China
| | - Liuyi Zhu
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy , South China University of Technology , Guangzhou 510006 , People's Republic of China
| | - Weijian Duan
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy , South China University of Technology , Guangzhou 510006 , People's Republic of China
| | - Chaohai Wei
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy , South China University of Technology , Guangzhou 510006 , People's Republic of China
| | - Chunhua Feng
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy , South China University of Technology , Guangzhou 510006 , People's Republic of China
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12
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Devlin TR, Kowalski MS, Pagaduan E, Zhang X, Wei V, Oleszkiewicz JA. Electrocoagulation of wastewater using aluminum, iron, and magnesium electrodes. JOURNAL OF HAZARDOUS MATERIALS 2019; 368:862-868. [PMID: 30336967 DOI: 10.1016/j.jhazmat.2018.10.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 10/05/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
Primary influent from a municipal wastewater treatment plant was electrochemically treated with sacrificial aluminum, iron, and magnesium electrodes. The influence of sacrificial anodes on the removal of chemical oxygen demand, total nitrogen, total phosphorus, and orthophosphate during sedimentation was investigated. Nitrification kinetics were assessed on treated supernatant and biogas production was monitored on settled solids. Changes in alkalinity, conductivity, and pH were also recorded. Aluminum and iron electrodes provided high rates of orthophosphate removal (i.e., 6.8 mg-P/mmol-e). Aluminum and iron electrodes also provided similar treatment to equivalent doses of alum and ferric salts (i.e., 38-68% chemical oxygen demand, 10-13% total nitrogen, and 67-93% total phosphorus). The estimated stochiometric ratio of aluminum and iron dosed to orthophosphate removed was approximately 1.3:1 and 4.1:1, respectively. Magnesium electrodes, on the other hand, removed orthophosphate at rates 8-9 times slower than aluminum and iron (i.e., 0.9 mg-P/mmol-e). Magnesium had to be dosed at a ratio of 13.5:1 orthophosphate for phosphorus removal. Orthophosphate removal by magnesium electrodes was most likely limited by electrolysis reactions responsible for increases in pH (i.e., 0.52 pH units/mmol-e). Magnesium electrodes removed 49% chemical oxygen demand and 21% total nitrogen at the high molar ratios required for orthophosphate removal.
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Affiliation(s)
- Tanner Ryan Devlin
- Department of Civil Engineering, University of Manitoba, Winnipeg, R3T 5V6, Canada.
| | - Maciej S Kowalski
- Department of Civil Engineering, University of Manitoba, Winnipeg, R3T 5V6, Canada
| | - Efren Pagaduan
- Department of Civil Engineering, University of Manitoba, Winnipeg, R3T 5V6, Canada
| | - Xugang Zhang
- Department of Civil Engineering, University of Manitoba, Winnipeg, R3T 5V6, Canada
| | - Victor Wei
- Department of Civil Engineering, University of Manitoba, Winnipeg, R3T 5V6, Canada
| | - Jan A Oleszkiewicz
- Department of Civil Engineering, University of Manitoba, Winnipeg, R3T 5V6, Canada
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