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Wei Y, Chen Y, Cao X, Yeh TCJ, Zhang J, Zhan Z, Cui Y, Li H. Modeling of Microplastics Migration in Soil and Groundwater: Insights into Dispersion and Particle Property Effects. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39090056 DOI: 10.1021/acs.est.4c05202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Migration of microplastics (MPs) in soil-groundwater systems plays a pivotal role in determining its concentration in aquifers and future threats to the terrestrial environment, including human health. However, existing models employing an advection-dispersion equation are insufficient to incorporate the holistic mechanism of MP migration. Therefore, to bridge the gap associated with MP migration in soil-groundwater systems, a dispersion-drag force coupled model incorporating a drag force on MPs along with dispersion is developed and validated through existing laboratory and field-scale experiments. The inclusion of the MP dispersion notably increased the global maximum particle velocity (vmaxp) of MPs, resulting in a higher concentration of MPs in the aquifer, which is also established by sensitivity analysis of MP dispersion. Additionally, increasing irrigation flux and irrigation areas significantly accelerates MP migration downward from soil to deep saturated aquifers. Intriguingly, vmaxp of MPs exhibited a nonlinear relationship with MPs' sizes smaller than 20 μm reaching the highest value (=1.64 × 10-5 m/s) at a particle size of 8 μm, while a decreasing trend was identified for particle sizes ranging from 20 to 100 μm because of the hindered effect by porous media and the weaker effect of the drag force. Moreover, distinct behaviors were observed among different plastic types, with poly(vinyl chloride), characterized by the highest density, displaying the lowest vmaxp and minimal flux entering groundwater. Furthermore, the presence of a heterogeneous structure with lower hydraulic conductivity facilitated MP dispersion and promoted their migration in saturated aquifers. The findings shed light on effective strategies to mitigate the impact of MPs in aquifers, contributing valuable insights to the broader scientific fraternity.
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Affiliation(s)
- Yaqiang Wei
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yuling Chen
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Xinde Cao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tian-Chyi Jim Yeh
- Department of Hydrology and Atmospheric Science, University of Arizona, Tucson, Arizona 85721, United States
| | - Jiao Zhang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Zi Zhan
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yuedong Cui
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Hui Li
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
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Chen H, Huang D, Zhou W, Deng R, Yin L, Xiao R, Li S, Li F, Lei Y. Hotspots lurking underwater: Insights into the contamination characteristics, environmental fates and impacts on biogeochemical cycling of microplastics in freshwater sediments. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:135132. [PMID: 39002483 DOI: 10.1016/j.jhazmat.2024.135132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/19/2024] [Accepted: 07/05/2024] [Indexed: 07/15/2024]
Abstract
The widespread presence of microplastics (MPs) in aquatic environments has become a significant concern, with freshwater sediments acting as terminal sinks, rapidly picking up these emerging anthropogenic particles. However, the accumulation, transport, degradation and biochemical impacts of MPs in freshwater sediments remain unresolved issues compared to other environmental compartments. Therefore, this paper systematically revealed the spatial distribution and characterization information of MPs in freshwater (rivers, lakes, and estuaries) sediments, in which small-size (<1 mm), fibers, transparent, polyethylene (PE), and polypropylene (PP) predominate, and the average abundance of MPs in river sediments displayed significant heterogeneity compared to other matrices. Next, the transport kinetics and drivers of MPs in sediments are summarized, MPs transport is controlled by the particle diversity and surrounding environmental variability, leading to different migration behaviors and transport efficiencies. Also emphasized the spatio-temporal evolution of MPs degradation processes and biodegradation mechanisms in sediments, different microorganisms can depolymerize high molecular weight polymers into low molecular weight biodegradation by-products via secreting hydrolytic enzymes or redox enzymes. Finally, discussed the ecological impacts of MPs on microbial-nutrient coupling in sediments, MPs can interfere with the ecological balance of microbially mediated nutrient cycling by altering community networks and structures, enzyme activities, and nutrient-related functional gene expressions. This work aims to elucidate the plasticity characteristics, fate processes, and potential ecological impact mechanisms of MPs in freshwater sediments, facilitating a better understanding of environmental risks of MPs in freshwater sediments.
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Affiliation(s)
- Haojie Chen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Danlian Huang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China; Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, Guangdong, PR China.
| | - Wei Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Rui Deng
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
| | - Lingshi Yin
- College of Water Resources & Civil Engineering, Hunan Agricultural University, Changsha 410128, PR China
| | - Ruihao Xiao
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Sai Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Fei Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Yang Lei
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
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Peleg E, Teitelbaum Y, Arnon S. Exploring the influence of sediment motion on microplastic deposition in streambeds. WATER RESEARCH 2024; 249:120952. [PMID: 38101045 DOI: 10.1016/j.watres.2023.120952] [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: 10/04/2023] [Revised: 11/09/2023] [Accepted: 11/29/2023] [Indexed: 12/17/2023]
Abstract
Microplastics (MP) of all sizes and densities have been found deposited in streambeds. Several delivery processes were proposed to explain these observations. However, none of the previous studies explored these processes systematically, especially in cases of streambeds made of fine sediments that are regularly in motion. In this study, we quantified the effect of streambed motion on the deposition and accumulation of MP in streambed sediments using particle tracking simulations in a numerical flow and transport model. The model was run for streamwater velocities of 0.1-0.5 m s-1 and median grain sizes of 0.15-0.6 mm. Streambed morphodynamics were estimated from these input parameters using empirical relationships. MP propensity to become trapped in porous media was simulated using a filtration coefficient. For each grain size and streamwater velocity, a wide variety of filtration coefficients was used in simulations in order to predict the fate of particles in the sediment. We found that exchange due to sediment turnover leads to burial and long-term deposition of MP that originally were not expected to enter the bed due to size exclusion. The results also show that in streambeds with fine sediments, localized deposits of MP are expected to occur as a horizontal layer below the moving fraction of the bed (upper layer). However, increasing celerity reduces the depth of MP deposition in the streambed. We conclude that models that do not include the effect of bed motion on MP deposition are likely miscalculating the deposition, retention, resuspensions and long-term accumulation of MP in streambed sediments.
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Affiliation(s)
- Eshel Peleg
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel
| | - Yoni Teitelbaum
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel
| | - Shai Arnon
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel.
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Wang T, Li B, Shi H, Ding Y, Chen H, Yuan F, Liu R, Zou X. The processes and transport fluxes of land-based macroplastics and microplastics entering the ocean via rivers. JOURNAL OF HAZARDOUS MATERIALS 2024; 466:133623. [PMID: 38301445 DOI: 10.1016/j.jhazmat.2024.133623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/03/2024]
Abstract
Approximately 80% of marine plastic waste originates from land-based sources and enters oceans through rivers. Hence, to create effective regulations, it is crucial to thoroughly examine the processes by which land-based plastic waste flows into marine environments. To this end, this review covers the complete journey of macro- and microplastics from their initial input into rivers to their ultimate release into oceans. Here, we also discuss the primary influencing factors and current popular research topics. Additionally, the principles, applicability, accuracy, uncertainty, and potential improvement of the standard methods used for flux estimation at each stage are outlined. Emission estimates of land-based macro- and microplastics are typically assessed using the emission factor approach, coefficient accounting approach, or material flow analysis. Accurately estimating mismanaged plastic waste is crucial for reducing uncertainty in the macroplastic emission inventory. In our review of the processes by which land-originating plastics enter rivers, we categorized them into two major types: point-source and diffuse-source pollution. Land surface hydrological models simulate transport from diffuse sources to rivers, necessitating further research. Riverine (micro)plastic flux to the ocean is often estimated using monitoring statistics and watershed hydrological models at the watershed scale; however, standardized monitoring methods have not yet been established. At the global scale, algorithms based on river datasets are often used, which require further improvements in river data selection and microplastic number-mass conversion factors. Furthermore, the article summarizes the accuracy and sources of uncertainty of various methods. Future research efforts should focus on quantifying and mitigating uncertainties in resultant projections. Overall, this review deepens our understanding of the processes by which land-based plastic waste enters the ocean and helps scholars efficiently select or improve relevant methods when studying land-ocean transport fluxes.
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Affiliation(s)
- Teng Wang
- Key Laboratory of Marine Hazards Forecasting, Ministry of Natural Resources, Hohai University, Nanjing 210024, China; Jiangsu Province Engineering Research Center for Marine Bio-resources Sustainable Utilization & Nanjing Outskirts Sea-Atmosphere Interface Field Scientific Observation Research Station & College of Oceanography, Hohai University, Nanjing 210024, China.
| | - Baojie Li
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Huahong Shi
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Yongcheng Ding
- School of Geography and Ocean Science, Nanjing University, Nanjing 210093, China; Shanghai Academy of Environmental Sciences, Shanghai 200233, China
| | - Hongyu Chen
- School of Geography and Ocean Science, Nanjing University, Nanjing 210093, China
| | - Feng Yuan
- School of Geography and Ocean Science, Nanjing University, Nanjing 210093, China
| | - Rongze Liu
- Jiangsu Province Engineering Research Center for Marine Bio-resources Sustainable Utilization & Nanjing Outskirts Sea-Atmosphere Interface Field Scientific Observation Research Station & College of Oceanography, Hohai University, Nanjing 210024, China
| | - Xinqing Zou
- School of Geography and Ocean Science, Nanjing University, Nanjing 210093, China.
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