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Wu X, Yang S, Li W, Wang J, Dular M, Tan X. Improving Microcystis aeruginosa removal efficiency through enhanced sonosensitivity of nitrogen-doped nanodiamonds. ULTRASONICS SONOCHEMISTRY 2024; 109:106993. [PMID: 39047459 DOI: 10.1016/j.ultsonch.2024.106993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 07/14/2024] [Accepted: 07/15/2024] [Indexed: 07/27/2024]
Abstract
Traditional methods for algae removal in drinking water treatment, such as coagulation and sedimentation, face challenges due to the negative charge on algae cells' surfaces, resulting in ineffective removal. Ultrasonic cavitation has shown promise in enhancing coagulation performance by disrupting extracellular polymer structures and improving cyanobacteria removal through various mechanisms like shear force and free radical reactions. However, the short lifespan and limited mass transfer distance of free radicals in conventional ultrasonic treatment lead to high energy consumption, limiting widespread application. To overcome these limitations and enhance energy efficiency, advanced carbon-based materials were developed and tested. Nitrogen-doped functional groups on nanodiamond surfaces were found to boost sonosensitivity by increasing the production of reactive oxygen species at the sonosensitizer-water interface. Utilizing low-power ultrasound (0.12 W/mL) in combination with N-ND treatment for 5 min, removal rates of Microcystis aeruginosa cells in water exceeded 90 %, with enhanced removal of algal organic matters and microcystins in water. Visualization through confocal microscopy highlighted the role of positively charged nitrogen-doped nanodiamonds in aggregating algae cells. The synergy between cell capturing and catalysis of N-ND indicates that efficient mass transfer of free radicals from the sonosensitizer's surface to the microalgae's surface is critical for promoting cyanobacteria floc formation. This study underscores the potential of employing a low-intensity ultrasound and N-ND system in effectively improving algae removal in water treatment processes.
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Affiliation(s)
- Xiaoge Wu
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Su Yang
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Wenshu Li
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - JuanJuan Wang
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225009, China.
| | - Matevž Dular
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia.
| | - Xiao Tan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
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Peng Y, Xiao X, Ren B, Zhang Z, Luo J, Yang X, Zhu G. Biological activity and molecular mechanism of inactivation of Microcystis aeruginosa by ultrasound irradiation. JOURNAL OF HAZARDOUS MATERIALS 2024; 468:133742. [PMID: 38367436 DOI: 10.1016/j.jhazmat.2024.133742] [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: 10/13/2023] [Revised: 02/05/2024] [Accepted: 02/05/2024] [Indexed: 02/19/2024]
Abstract
Harmful algal blooms (HABs) significantly impact on water quality and ecological balance. Ultrasound irradiation has proven to be an effective method for algal control. Nevertheless, the molecular mechanisms underlying the inactivation of M. aeruginosa by ultrasound are still unknown. In this study, the physiological activity and molecular mechanism of algal cells exposed to different frequencies of ultrasound were studied. The results indicated a pronounced inhibition of algal cell growth by high-frequency, high-dose ultrasound. Moreover, with increasing ultrasound dosage, there was a higher percentage of algal cell membrane ruptures. SEM and TEM observed obvious disruptions in membrane structure and internal matrix. Hydroxyl radicals generated by high-frequency ultrasound inflicted substantial cell membrane damage, while increased antioxidant enzyme activities fortified cells against oxidative stress. Following 2 min of ultrasound irradiation at 740 kHz, significant differential gene expression occurred in various aspects, including energy metabolism, carbohydrate metabolism, and environmental information processing pathways. Moreover, ultrasound irradiation influenced DNA repair and cellular apoptosis, suggesting that the algal cells underwent biological stress to counteract the damage caused by ultrasound. These findings reveal that ultrasound irradiation inactivates algae by destroying their cell structures and metabolic pathways, thereby achieving the purpose of algal suppression.
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Affiliation(s)
- Yazhou Peng
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Xiang Xiao
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Bozhi Ren
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China.
| | - Zhi Zhang
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Jun Luo
- Changsha Economic and Technical Development Zone Water Purification Engineering Co., Ltd, Changsha 410100, China
| | - Xiuzhen Yang
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Guocheng Zhu
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China
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Xu H, Tang Z, Liang Z, Chen H, Dai X. Neglected methane production and toxicity risk in low-frequency ultrasound for controlling harmful algal blooms. ENVIRONMENTAL RESEARCH 2023; 232:116422. [PMID: 37327839 DOI: 10.1016/j.envres.2023.116422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/25/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023]
Abstract
Algal blooms are regarded as a significant source of CH4 emissions. Ultrasound has been gradually employed as a fast and efficient algae removal technology in recent years. However, the changes in water environment and potential ecological effects caused by ultrasonic algae removal are not fully clear. Here, a 40-day microcosm study was performed to simulate the collapse of Microcystis aeruginosa blooms after ultrasonic treatment. The results showed that low-frequency ultrasound at 29.4 kHz for 15 min removed 33.49% of M. aeruginosa and contributed to the destruction of cell structure, but it intensified the leakage of intracellular algal organic matter and microcystins. The accelerated collapse of M. aeruginosa blooms after ultrasonication promoted the rapid formation of anaerobic and reductive methanogenesis conditions, and elevated dissolved organic carbon content. Moreover, the release of labile organics, including tyrosine, tryptophan, protein-like compositions, and aromatic proteins, was facilitated by the collapse of M. aeruginosa blooms after ultrasonic treatment, and they supported the growth of anaerobic fermentation bacteria and hydrogenotrophic Methanobacteriales. This was also demonstrated by the increase in methyl-coenzyme M reductase (mcrA) genes in sonicated algae added treatments at the end of incubation. Finally, the CH4 production in sonicated algae added treatments was 1.43-fold higher than that in non-sonicated algae added treatments. These observations suggested that ultrasound for algal bloom control potentially increased the toxicity of treated water and its greenhouse gas emissions. This study can provide new insights and guidance to evaluate environmental effects of ultrasonic algae removal.
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Affiliation(s)
- Haolian Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Zhenzhen Tang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Zixuan Liang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Hongbin Chen
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
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Peng Y, Yang X, Huang H, Su Q, Ren B, Zhang Z, Shi X. Fluorescence and molecular weight dependence of disinfection by-products formation from extracellular organic matter after ultrasound irradiation. CHEMOSPHERE 2023; 323:138279. [PMID: 36863625 DOI: 10.1016/j.chemosphere.2023.138279] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Algal blooms have a negative impact on the safety of drinking water. Ultrasonic radiation technology is an "environment-friendly" technology that is widely used in algae removal. However, this technology leads to the release of intracellular organic matter (IOM), which is an important precursor of disinfection by-products (DBPs). This study investigated the relationship between the release of IOM in Microcystis aeruginosa and the generation of DBPs after ultrasonic radiation as well as analyzed the generation mechanism of DBPs. Results showed that the content of extracellular organic matter (EOM) in M. aeruginosa increased in the order of 740 kHz >1120 kHz >20 kHz after 2 min of ultrasonic radiation. Organic matter with a molecular weight (MW) greater than 30 kDa increased the most, including protein-like, phycocyanin (PC) and chlorophyll a, followed by small-molecule organic matter less than 3 kDa, mainly humic-like substances and protein-like. DBPs with an organic MW range of less than 30 kDa were dominated by trichloroacetic acid (TCAA), while those with an MW greater than 30 kDa had the highest trichloromethane (TCM) content. Ultrasonic irradiation changed the organic structure of EOM, affected the amount and type of DBPs, and tended to generate TCM.
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Affiliation(s)
- Yazhou Peng
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Xiongwei Yang
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Hongqi Huang
- Changsha Economic and Technical Development Zone Water Purification Engineering Co.,Ltd, Changsha, 410100, China
| | - Qitao Su
- Changsha Economic and Technical Development Zone Water Purification Engineering Co.,Ltd, Changsha, 410100, China
| | - Bozhi Ren
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
| | - Zhi Zhang
- Laboratory of Three Gorges Reservoir Region, Chongqing University, Chongqing, 400045, China
| | - Xueping Shi
- Shanghai Urban Construction Design and Research Institute, Shanghai, 200125, China
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Ren B, Weitzel KA, Duan X, Nadagouda MN, Dionysiou DD. A comprehensive review on algae removal and control by coagulation-based processes: mechanism, material, and application. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121106] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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