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Ruan J, Yang J, Wang X, Liang C, Li L, Zeng Y, Wang J, Li Y, Huang W, Chen C. Heteroaggregation kinetics of oppositely charged nanoplastics in aquatic environments: Effects of particle ratio, solution chemistry, and interaction sequence. JOURNAL OF HAZARDOUS MATERIALS 2024; 475:134857. [PMID: 38876017 DOI: 10.1016/j.jhazmat.2024.134857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 06/05/2024] [Accepted: 06/06/2024] [Indexed: 06/16/2024]
Abstract
Interactions between positively charged amino-modified (APS) and negatively charged bare (BPS) polystyrene nanoplastics may cause heteroaggregation in aquatic environments. This study investigated the effects of particle concentration ratio, solution chemistry [electrolytes, pH, and natural organic matter (NOM)], and interaction sequence on their heteroaggregation kinetics. In the absence of electrolytes and NOM, the APS/BPS ratio for attaining maximum heteroaggregation rate (khetero) increased from APS/BPS= 3/7 to APS/BPS= 1/1 as pH increased from 4 to 10, indicating that electrostatic interactions dominated heteroaggregation. In the absence of NOM, khetero ranked APS/BPS= 2/3 > APS/BPS= 1/1 > APS/BPS= 3/2. Colloidal stability decreased linearly as pH increased from 4 to 8 at APS/BPS= 1/1, while diffusion-limited heteroaggregation persisted at pH 10. In NaCl solution, humic acid (HA) retarded heteroaggregation more effectively than sodium alginate (SA) via steric hindrance and weakening electrostatic interactions, following the modified Derjaguin-Landau-Verwey-Overbeek (MDLVO) theory. Compared with simultaneous interactions among APS, BPS, NaCl, and NOM, the NOM retardation effects on heteroaggregation weakened if delaying its interaction with others. In CaCl2 solution, the effects of NOM on heteroaggregation depended on counterbalance among charge screening, steric hindrance, and calcium bridging. These findings highlight the important role of heteroaggregation between oppositely charged nanoplastics on their fate and transport in aquatic environments.
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Affiliation(s)
- Jiahui Ruan
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Jiahui Yang
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Xingyan Wang
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Cuihua Liang
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Lihua Li
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Yaqi Zeng
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Junhua Wang
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Yongtao Li
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901, USA
| | - Chengyu Chen
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China.
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Zeng D, Yang C, Huang Z, Liu Y, Liu S, Zhang Z, Huang W, Dang Z, Chen C. Heteroaggregation kinetics of nanoplastics and soot nanoparticles in aquatic environments. JOURNAL OF HAZARDOUS MATERIALS 2024; 472:134564. [PMID: 38743982 DOI: 10.1016/j.jhazmat.2024.134564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 04/29/2024] [Accepted: 05/07/2024] [Indexed: 05/16/2024]
Abstract
Heteroaggregation between polystyrene nanoplastics (PSNPs) and soot nanoparticles (STNPs) in aquatic environments may affect their fate and transport. This study investigated the effects of particle concentration ratio, electrolytes, pH, and humic acid on their heteroaggregation kinetics. The critical coagulation concentration (CCC) ranked CCCPSNPs > CCCPSNPs-STNPs > CCCSTNPs, indicating that heteroaggregation rates fell between homoaggregation rates. In NaCl solution, as the PSNPs/STNPs ratio decreased from 9/1 to 3/7, heteroaggregation rate decreased and CCCPSNPs-STNPs increased from 200 to 220 mM due to enhanced electrostatic repulsion. Outlier was observed at PSNPs/STNPs= 1/9, where CCCPSNPs-STNPs= 170 mM and homoaggregation of STNPs dominated. However, in CaCl2 solution where calcium bridged with STNPs, heteroaggregation rate increased and CCCPSNPs-STNPs decreased from 26 to 5 mM as the PSNPs/STNPs ratio decreasing from 9/1 to 1/9. In composite water samples, heteroaggregation occurred only at estuarine and marine salinities. Acidic condition promoted heteroaggregation via charge screening. Humic acid retarded or promoted heteroaggregation in NaCl or CaCl2 solutions by steric hindrance or calcium bridging, respectively. Other than van der Waals attraction and electrostatic repulsion, heteroaggregation was affected by steric hindrance, hydrophobic interactions, π - π interactions, and calcium bridging. The results highlight the role of black carbon on colloidal stability of PSNPs in aquatic environments.
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Affiliation(s)
- Dehua Zeng
- College of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Chen Yang
- College of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Ziqing Huang
- College of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Yanjun Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Sijia Liu
- College of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Zhiyu Zhang
- College of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Zhi Dang
- College of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Chengyu Chen
- College of Natural Resources and Environment, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, South China Agricultural University, Guangzhou 510642, China.
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Zhang G, Wang B, Jiang N, Pang K, Wu W, Yin X. Effect of water-soluble polymers on the transport of functional group-modified polystyrene nanoplastics in goethite-coated saturated porous media. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:134044. [PMID: 38493628 DOI: 10.1016/j.jhazmat.2024.134044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/07/2024] [Accepted: 03/13/2024] [Indexed: 03/19/2024]
Abstract
The research on the impact of water-soluble polymers (WSPs) on the migration and fate of plastic particles is extremely limited. This article explored the effects of polyacrylic acid (PAA, a common WSP) and physicochemical factors on the transport of polystyrene nanoparticles (PSNPs-NH2/COOH) with different functional groups in QS (quartz sand) and FOS (goethite-modified quartz sand, simulates mineral colloids). Research has shown that PAA can selectively adsorb onto the surface of PSNPs-NH2, forming ecological corona heterogeneous aggregates. This process increased the spatial hindrance and elastic repulsion, resulting in the recovery of PSNPs-NH2 always exceeding that of PSNPs-COOH. Overall, PAA can hinder the migration of PSNPs in QS but can promote their migration in FOS. When multivalent cations coexist with PAA, the transport of PSNPs in the media is primarily affected by cation bridging and CH-cation-π interaction. The presence of oxyanions and PAA prevents PSNPs from following the Hofmeister rule and promotes their migration (PO43-: 82.34 ± 0.16% to 94.63 ± 2.82%>SO42-: 81.38 ± 2.73% to 91.15 ± 0.93%>NO3-: 55.85 ± 0.70%-87.16 ± 3.80%). The findings of this study contribute significantly to a better understanding of the migration of WSPs and group-modified NPs in complex saturated porous media.
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Affiliation(s)
- Guangcai Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Binying Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Nan Jiang
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Kejing Pang
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Wenbing Wu
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Xianqiang Yin
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, China.
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Yang X, Huang G, Chen Z, Feng Q, An C, Lyu L, Bi H, Zhou S. Spotlight on the vertical migration of aged microplastics in coastal waters. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:134040. [PMID: 38503206 DOI: 10.1016/j.jhazmat.2024.134040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/09/2024] [Accepted: 03/13/2024] [Indexed: 03/21/2024]
Abstract
Coastal waters are complex and dynamic areas with unique environmental attributes that complicate the vertical migration of microplastics (MPs). The MPs that enter coastal waters from diverse sources, including terrestrial, riverine, oceanic, and shoreline inputs undergo various aging pathways. In this study, the variations in the physiochemical characteristics of MPs undergoing various aging pathways and their vertical migration under dynamic conditions subjected to the effects of different MP characteristics and coastal environmental features were comprehensively explored. Opposite effects of aging on the vertical migration of hydrophobic and hydrophilic MPs were observed, with aging appearing to promote the dispersion of hydrophobic MPs but enhance the vertical migration of hydrophilic ones. The positive role of salinity and the negative role of humic acid (HA) concentrations on MP vertical migration were identified, and the mechanisms driving these effects were analyzed. Notably, intense turbulence not only promoted the floating of positively buoyant MPs but also reversed the migration direction of negatively buoyant MPs from downward to upward. Aging-induced changes in MP characteristics had a limited effect on MP vertical migration. The inherent characteristics of MPs and the surrounding environmental features, however, played major roles in their vertical migration dynamics. ENVIRONMENTAL IMPLICATION: Microplastics (MPs) have emerged as a significant global environmental concern and the coastal zones are the hotspots for MP pollution due to their high population density. This study comprehensively investigated the variations in the physiochemical characteristics of MPs undergoing various aging pathways. Their vertical migration patterns under dynamic conditions subjected to the effects of different MP characteristics and coastal environmental features were revealed. The roles of turbulence and MP density in their migration were identified. The findings of this study have important implications for understanding the transport and determining the ecological risks of MPs in coastal waters.
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Affiliation(s)
- Xiaohan Yang
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
| | - Guohe Huang
- Environmental Systems Engineering, Faculty of Engineering and Applied Science, University of Regina, Regina, SK S4S 0A2, Canada
| | - Zhikun Chen
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
| | - Qi Feng
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
| | - Chunjiang An
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada.
| | - Linxiang Lyu
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
| | - Huifang Bi
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
| | - Siyuan Zhou
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
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Okutan H, Hul G, Stoll S, Le Coustumer P. Retention and Transport of Nanoplastics with Different Surface Functionalities in a Sand Filtration System. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 14:32. [PMID: 38202487 PMCID: PMC11326042 DOI: 10.3390/nano14010032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024]
Abstract
The efficiency of sand filtration was investigated in terms of the behavior of the nanoplastics (NPLs) with different surface functionalities. The initial condition concentrations of NPLs were varied, and their effects on retention and transport were investigated under a constant flow rate in saturated porous media. The behavior of NPLs in this porous system was discussed by considering Z- average size and zeta (ζ) potential measurements of each effluent. The retention efficiencies of NPLs were ranked as functionalized with amidine [A-PS]+ > with sulfate [S-PS]- > with surfactant-coated amidine [SDS-A-PS]-. The reversibility of the adsorption process was revealed by introducing surfactant into the sand filter system containing adsorbed [A-PS]+ at three different initial state concentration conditions. The deposition behavior on sand grain showed that positively charged NPLs were attached to the quartz surface, and negatively charged NPLs were attached to the edge of the clay minerals, which can be caused by electrical heterogeneities. The homoaggregates made of positively charged NPLs were more compact than those made of negatively charged NPLs and surfactant-coated NPLs. An anti-correlation was revealed, suggesting a connection between the fractal dimension (Df) of NPL aggregates and retention efficiencies. Increased Df values are associated with decreased retention efficiencies.The findings underscore the crucial influence of NPL surface properties in terms of retention efficiency and reversible adsorption in the presence of surfactants in sand filtration systems.
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Affiliation(s)
- Hande Okutan
- Ecole Doctorale, Sciences et Technologies, Université de Bordeaux Montaigne, 33607 Pessac, France
- Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, 1205 Geneva, Switzerland
- Department of Geological Engineering, Mugla Sitki Kocman University, Mugla 48000, Türkiye
| | - Gabriela Hul
- Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, 1205 Geneva, Switzerland
| | - Serge Stoll
- Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, 1205 Geneva, Switzerland
| | - Philippe Le Coustumer
- Ecole Doctorale, Sciences et Technologies, Université de Bordeaux Montaigne, 33607 Pessac, France
- Earth Sciences Department, Université de Bordeaux, 33615 Pessac, France
- Bordeaux Imaging Center, Université de Bordeaux, CNRS-UAR3420-INSERM US4, 33000 Bordeaux, France
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Wang Y, Chen X. Aggregation behavior of polyethylene microplastics in the nearshore environment: The role of particle size, environmental condition and turbulent flow. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:165941. [PMID: 37536586 DOI: 10.1016/j.scitotenv.2023.165941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/29/2023] [Accepted: 07/29/2023] [Indexed: 08/05/2023]
Abstract
Estuary and coastal waters are hotspot areas for microplastics (MPs) pollution. MPs of varying sizes converge in this complex nearshore environment. Aggregation is an important process that affects the transport and fate of MPs in the aqueous environment. Nevertheless, the influence of different factors on the aggregation behavior and the aggregates structure of MPs is unclear. In this study, the aggregation behavior and the aggregates structure of polyethylene microplastics (PEs) of different sizes under the impact of nearshore environmental conditions (i.e., salinity gradient, dissolved organic matter-DOM, turbulent flow) were investigated. The results show that particle size was the dominant factor affecting the stability of PEs in the aqueous environment, and the critical coagulation concentration (CCC) of PEs shifts to the right with increasing size. It was also found that the size of PEs stable aggregates is negatively correlated with the turbulent kinetic energy dissipation rate. The particle size of PEs can significantly affect the fractal dimension (FD) of stable aggregates, and the smaller the particle size, the more compact the aggregates formed. Moreover, salinity and DOM control the size and FD of PEs stable aggregates through different mechanisms. The findings of this study will be helpful for the prediction of the transport and fate of MPs in the aqueous environment.
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Affiliation(s)
- Yi Wang
- Fujian Provincial Engineering Research Center for Monitoring and Assessing Terrestrial Disasters, Fujian Normal University, Fuzhou 350117, China; School of Geographical Sciences, School of Carbon Neutrality Future Technology, Fujian Normal University, Fuzhou 350117, China; State Key Laboratory for Subtropical Mountain Ecology, Ministry of Science and Technology and Fujian Province, Fujian Normal University, Fuzhou 350117, China
| | - Xingwei Chen
- Fujian Provincial Engineering Research Center for Monitoring and Assessing Terrestrial Disasters, Fujian Normal University, Fuzhou 350117, China; School of Geographical Sciences, School of Carbon Neutrality Future Technology, Fujian Normal University, Fuzhou 350117, China; State Key Laboratory for Subtropical Mountain Ecology, Ministry of Science and Technology and Fujian Province, Fujian Normal University, Fuzhou 350117, China.
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Li Y, Du X, Li W, Jiang Q, Ye Y, Yang Y, Liu X, Zhao Y, Che X. Two genes related to apoptosis in the hepatopancreas of juvenile prawn, Macrobrachium nipponense: Molecular characterization and transcriptional response to nanoplastic exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162863. [PMID: 36931509 DOI: 10.1016/j.scitotenv.2023.162863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 05/06/2023]
Abstract
Nanoplastics have been widely found in the global water environment, causing plastic pollution and affecting human beings and numerous organisms. Studies involving freshwater crustacean exposure to nanoplastics, however, are limited. In this study, juvenile prawns (Macrobrachium nipponense) were exposed to 75 nm polystyrene nanoplastics at different concentrations (0, 5, 10, 20, or 40 mg/L) for a 28-d chronic exposure experiment. To study the effects of exposure to nanoplastics on hepatopancreas cell apoptosis, C-Jun N-terminal kinase (JNK) and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) genes were selected, and hepatotoxic enzyme activities and Toll pathway- and apoptosis-related gene expression were determined. For the first time, full-length Mn-JNK and Mn-PIK3CA cDNAs were cloned from M. nipponense. Homologous comparisons showed that JNK and PIK3CA had conserved functional sequences. The apoptosis rate in the high-concentration nanoplastic group (40 mg/L) was significantly higher than in the low-concentration nanoplastic (5 mg/L) and control groups (0 mg/L). The alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyl transpeptidase (GGT) and xanthine oxidase (XOD) enzyme activities in the hepatopancreas increased with exposure to higher concentrations of nanoplastics. In addition, the levels of apoptosis- and Toll pathway-related gene expression and JNK and PIK3CA gene expression were initially increased, then decreased with exposure to higher concentrations of nanoplastics. This study showed that polystyrene nanoplastics activate toll-related pathways leading to apoptosis and hepatopancreas damage, which provides theoretical support for future aquatic toxicological research.
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Affiliation(s)
- Yiming Li
- Fishery Machinery and Instrument Research Institute, Chinese Academy of Fisheries Sciences, Shanghai 200092, China
| | - Xinglin Du
- School of Life Science, East China Normal University, Shanghai 200241, China
| | - Wen Li
- School of Life Science, East China Normal University, Shanghai 200241, China
| | - Qichen Jiang
- Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing 210017, China
| | - Yucong Ye
- School of Life Science, East China Normal University, Shanghai 200241, China
| | - Ying Yang
- School of Life Science, East China Normal University, Shanghai 200241, China
| | - Xingguo Liu
- Fishery Machinery and Instrument Research Institute, Chinese Academy of Fisheries Sciences, Shanghai 200092, China
| | - Yunlong Zhao
- School of Life Science, East China Normal University, Shanghai 200241, China.
| | - Xuan Che
- Fishery Machinery and Instrument Research Institute, Chinese Academy of Fisheries Sciences, Shanghai 200092, China.
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Jiang H, Bu J, Bian K, Su J, Wang Z, Sun H, Wang H, Zhang Y, Wang C. Surface change of microplastics in aquatic environment and the removal by froth flotation assisted with cationic and anionic surfactants. WATER RESEARCH 2023; 233:119794. [PMID: 36868113 DOI: 10.1016/j.watres.2023.119794] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 01/29/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Microplastics (MPs) are increasingly released into the environment due to the widespread usage and improper management of plastics. Considerable research efforts have been devoted to the remediation of MPs. Froth flotation has been demonstrated as an effective method to remove MPs in water and sediment. However, there is a lack of knowledge on the regulation of the hydrophobicity/hydrophilicity of MPs surfaces. We found that exposure to the natural environment resulted in the increased hydrophilicity of MPs. The flotation efficiencies of polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), and polyethylene glycol terephthalate (PET) MPs decreased to zero after six months of natural incubation in rivers. According to various characterizations, the hydrophilization mechanism is mainly correlated with surface oxidation and the deposition of clay minerals. Inspired by surface wettability conversion, we applied surfactants (collectors) to enhance MPs hydrophobicity and flotation efficiency. Anionic sodium oleate (NaOL) and cationic dodecyl trimethyl ammonium chloride (DTAC) were used to regulate surface hydrophobicity. The effects of collector concentration, pH, conditioning time, and metal ions on MPs flotation were thoroughly elucidated. Characterizations and adsorption experiments were performed to describe the heterogeneous adsorption of surfactants on MPs surfaces. The interaction between surfactants and MPs was explained through density functional theory (DFT) simulations. The dispersion energy between hydrophobic hydrocarbon chains attracts collectors on the MPs surface, and the collector molecules wrap and laminate to MPs surfaces. Flotation using NaOL exhibited a higher removal efficiency, and NaOL was environmentally friendly. Subsequently, we investigated the activation of Ca2+, Fe3+, and Al3+ to further improve the collecting efficiency of NaOL. Under the optimized conditions, MPs in natural rivers could be removed by froth flotation. This study shows the great promise of froth flotation for the application of MPs removal.
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Affiliation(s)
- Hongru Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Jiaqi Bu
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Kai Bian
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Jiming Su
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Zhiyi Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Han Sun
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Hui Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China.
| | - Yingshuang Zhang
- School of Chemical Engineering and Technology, Xinjiang University, 830017 Urumqi, Xinjiang, PR China.
| | - Chongqing Wang
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, PR China
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