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Xu H, Yang A, Pang Y, Pei H. Advances and challenges in the technologies for cyanobacterial cells removal in drinking water treatment. CHEMOSPHERE 2024; 359:142338. [PMID: 38754486 DOI: 10.1016/j.chemosphere.2024.142338] [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: 08/14/2023] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/18/2024]
Abstract
Harmful cyanobacteria in reservoirs pose a serious threat to drinking water safety due to the intracellular metabolites, such as toxins and unpleasant tastes & odours. Effective removal of harmful cyanobacteria with little to no cell damage is very important to ensure the safety of drinking water. This review first introduced development history of cyanobacterial removal technologies in drinking water treatment. Then, impacts of oxidation, coagulation and pre-oxidation enhanced coagulation processes on cyanobacterial removal and integrity of the cells were comprehensively evaluated and discussed. Oxidation can remove cyanobacteria, but high doses of oxidants can result in significant cell lysis and release of intracellular metabolites, especially when using chlorine or ozone. Although there is practically no cell damage during coagulation, the removal efficiency is low in many cases. Pre-oxidation may improve cyanobacterial removal by the subsequent solid-liquid separation processes, and moderate pre-oxidation with little to no cell lysis is very important. Mechanisms of interface interaction between pre-oxidants and cyanobacteria should be defined in future to ensure moderate pre-oxidation of algal cells. Fate of cyanobacterial cells in sludge is also reviewed because more and more waterworks return sludge supernatant to the inlet of plant. Damage to cyanobacterial cells in sludge depends mainly upon coagulant type and dosage, algal species, and cyanobacteria-containing sludge should be treated before cell lysis. Efficient techniques for harmless disposal of cyanobacteria-containing sludge should be developed in future. This paper will help to better understand the cyanobacterial removal processes and provide improved perspectives for future research in this field.
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Affiliation(s)
- Hangzhou Xu
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China
| | - Aonan Yang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Yiming Pang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Haiyan Pei
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China; Institute of Eco-Chongming (IEC), Shanghai, 202162, China.
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Zhang Y, Jie Y, Li J, Yu Y, Liang P, Hao Y, Bai M. Maintenance of cell integrity during hydroxyl radical rapid inactivation of Pseudanabaena sp. and simultaneous mineralization of odor compound 2-methylisoborneol. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168713. [PMID: 38007125 DOI: 10.1016/j.scitotenv.2023.168713] [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: 09/17/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 11/27/2023]
Abstract
Pseudanabaena sp. and the odor compound it produces, 2-methylisoborneol (2-MIB), has been reportedly responsible for off-flavor pollution worldwide, leading to substandard drinking water sensory indicators and serious water supply crises. In this paper, the hydroxyl radical (•OH) produced by the synergistic effect of strong ionization discharge and hydrodynamic cavitation rapidly inactivated Pseudanabaena sp. and simultaneously mineralized 2-MIB to a concentration of 2.57 ng/L, which is below the odor threshold of 10 ng/L for a total reactive oxidants (TRO) concentration of 1.2 mg/L within 12 s. Crucially, the intracellular 2-MIB level was maintained in approximately 155.26- 162.29 ng/L range, indicating that 2-MIB was not released from the cells. Based on the scanning electron microscopy (SEM) results, the integrity of Pseudanabaena sp. cells was maintained with intact membranes and no intracellular organic matters (IOM) released during •OH inactivation. In contrast, ClO2 caused severe membrane rupture and massive IOM release. Based on the gas chromatograph/mass spectrometer (GC/MS) analyses and mass spectral database, the chromatogram fitted the baseline with a TRO concentration of 4 mg/L and no peaks corresponding to intermediates were detected. Moreover, •OH could mineralize 2-MIB by opening the ring structures of 1,2,3,3-tetramethyl-4-cyclopentenone, neomenthol, and 2-methylcyclohexene-1-aldehyde to produce small-molecule compounds, finally leading to CO2 and H2O formation via three reaction pathways. Therefore, the •OH not only maintained the cell integrity of Pseudanabaena sp. during inactivation but also mineralized 2-MIB simultaneously.
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Affiliation(s)
- Yubo Zhang
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Ying Jie
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China; Fujian Institute of Geological Survey, Fuzhou 350013, China
| | - Jianlan Li
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Yixuan Yu
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
| | - Pengyu Liang
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Yiming Hao
- Marine Engineering College, Dalian Maritime University, Dalian 116026, China
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Li X, Xian X, Chen S, Song W, Yu X, Yu CP. Comparative study about ozonation to treat Microcystis-laden source water at the development and maintenance stage. CHEMOSPHERE 2023; 341:140045. [PMID: 37683947 DOI: 10.1016/j.chemosphere.2023.140045] [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: 11/20/2022] [Revised: 08/09/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023]
Abstract
The outbreak of toxic cyanobacteria blooms is hazardous to water safety. Ozonation has been used to treat cyanobacteria-laden source water. Generally, cyanobacterial blooms enter into a long-term maintenance stage from the bloom development, but how the changed bloom stage affects ozonation is still unknow. Herein, influences of ozonation on cell inactivation and microcystin removal of Microcystis at the development and maintenance stage, were investigated. Then, ozonation-assisted coagulation for Microcystis removal at the two stages was compared. Results showed no significant difference in the photosynthetic inactivation of Microcystis at both stages. Microcystis at the maintenance stage exhibited a lower loss of membrane integrity (268-480 M-1 s-1) than that at the development stage (413-596 M-1 s-1). However, the extracellular microcystin increased by 30-410% at the maintenance stage at a lower ratio of [O3: DOC] (0.10-0.80) compared to the development stage (0.21-1.68), mainly ascribed to a decrease in the ozonation efficiency for microcystin removal. This finding might result from the elevated biomass and N-containing organics as competitors to reduce microcystin ozonation. Meanwhile, it was possible to generate fewer hydroxyl radicals to oxidize microcystin at the maintenance stage than that at the development stage. Besides, the removal ratio of Microcystis after ozonation-assisted coagulation, was reduced by 46-230% at the maintenance stage, due to the insufficient modification of cellular surface or elevated organics of 3-30 kDa. This work indicated that ozonation is effective to treat Microcystis at the development stage of a bloom whist pre-ozonation might be an inappropriate choice at the long-term maintenance stage.
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Affiliation(s)
- Xi Li
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
| | - XuanXuan Xian
- College of The Environment & Ecology, Xiamen University, Xiamen, 361102, China.
| | - Sheng Chen
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
| | - Weijun Song
- College of Ecology and Resources Engineering, Wuyi University, Wuyishan, 354300, China.
| | - Xin Yu
- College of The Environment & Ecology, Xiamen University, Xiamen, 361102, China.
| | - Chang-Ping Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan.
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Wang J, Wang Y, Li W, Wu X. Enhancement of KMnO 4 treatment on cyanobacteria laden-water via 1000 kHz ultrasound at a moderate intensity. ULTRASONICS SONOCHEMISTRY 2023; 98:106502. [PMID: 37379744 PMCID: PMC10320383 DOI: 10.1016/j.ultsonch.2023.106502] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/03/2023] [Accepted: 06/20/2023] [Indexed: 06/30/2023]
Abstract
1000 kHz high-frequency ultrasound at 0.12 and 0.39 W/mL intensity was used to enhance the inactivation of suspensions of Microcystis aeruginosa cells using KMnO4. With 10 mg/L of KMnO4, ultrasound at 0.12 W/mL intensity was found to be effective in inactivating the cyanobacteria within 10 min. A Weibull model was found to describes the inactivation well. Its concave shape shows that some cells have a certain resistance to this treatment. Cytometry and microscopic analysis confirm that the treatment damages cell integrity. Despite that the extracellular organic matter in the water was not significantly increased. The concentration of extracellular cyanobacterial toxins even decreased. The filtered suspension of inactivated cyanobacteria was used to cultivate mung beans, and the suspension did not hinder their germination. This provides a new idea for using cyanobacteria-laden wastewater. These findings suggest a technique for speeding up the oxidation of Microcystis cells using KMnO4 with ultrasound at moderate intensity, which provide new insights into the biological effects of ultrasound.
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Affiliation(s)
- JuanJuan Wang
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China; Key Laboratory of Cultivated Land Quality Monitoring and Evaluation, Ministry of Agriculture and Rural Affairs, Yangzhou 225127, China; Jiangsu Collaborative Innovation Centre for Solid Organic Waste Resource Utilization, Nanjing, Jiangsu 210095, China
| | - Yuting Wang
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Wenshu Li
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Xiaoge Wu
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Collaborative Innovation Centre for Solid Organic Waste Resource Utilization, Nanjing, Jiangsu 210095, China.
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Pan W, Li J, Zhang X, Liang S, Kang Y, Deng R, Gu L, He Q. Effect of KMnO 4/pH adjustment of extracellular polymeric substances under waste activated sludge on sludge dewatering. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:67326-67337. [PMID: 37106308 DOI: 10.1007/s11356-023-27171-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 04/18/2023] [Indexed: 05/25/2023]
Abstract
In this study, we examine the dewaterability of sludge after treatment by KMnO4 at various pH levels, with the goal of understanding the dewaterability of strong oxidizers to waste activated sludge. Good dewatering performance is observed, with capillary suction times (CST) reduced from 263.4 to 30.1 s, and specific resistance to filtration (SRF) falling by 19.6%. Proteins and polysaccharides in tightly bound extracellular polymeric substances (EPS) were also significantly reduced. Based on spectroscopic and electrochemical analysis, we propose mechanisms for the improved dewatering in terms of changes to the sludge's physicochemical properties and EPS. Under strong oxidation, the structure surrounding the bound water is oxidized and bound water is released, so the dewaterability of the sludge is improved.Weiliang Pan and Jiaoni Li contributed equally to this work.
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Affiliation(s)
- Weiliang Pan
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, China.
| | - Jiaoni Li
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Xun Zhang
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Shan Liang
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Yinghao Kang
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Rui Deng
- School of Architecture and Urban Planning, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Li Gu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Qiang He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, Chongqing, 400045, China
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