农业环境科学学报2025，Vol.44Issue(7)：1836-1847,12.DOI:10.11654/jaes.2024-0890
微塑料在紊流中的聚沉行为
Aggregation and sedimentation behavior of microplastics in turbulence
摘要
Abstract
This study aims to investigate the aggregation and sedimentation characteristics of microplastics in sand-carrying turbulence and to reveal the underlying mechanisms.By employing a self-developed isotropic uniform turbulence device and particle tracking velocimetry(PTV)method,the aggregation and sedimentation behavior of microplastics were analyzed.The results indicated that an increase in water flow shear strength could promote the aggregation of microplastics,but excessively high shear strength might disrupt the structure of aggregates,limiting their further enlargement.Concurrently,the presence of sediment in turbulent flow could facilitate the formation of larger microplastic aggregates.As the shear rate increased,the overall structural fractal dimension of particles in water increased,while the surface morphological fractal dimension decreased,and these trends gradually slowed down with further increases in shear rate.In sand-carrying turbulence,both types of fractal dimensions of particles were slightly higher than those in clear water turbulence.In clear water turbulence,the overall settling velocity of microplastic particles first increased and then decreased with increasing shear rate,whereas in sand-carrying turbulence,the overall settling velocity increased with increasing shear rate.Regardless of the presence of sediment,the minimum settling velocity of microplastic particles was directly proportional to particle size,while the maximum settling velocity was inversely proportional to particle size.Smaller microplastic particles exhibited poorer settling stability in turbulence and were more significantly affected by turbulence.The study demonstrates that turbulence has a dual effect on the aggregation of microplastics and can also cause changes in the structure and surface morphology of aggregates.The sedimentation behavior of microplastics is closely related to particle size,and the presence of sediment not only promotes the aggregation of microplastics but also alters their sedimentation behavior.关键词
微塑料/紊流/泥沙/聚集/沉降Key words
microplastics/turbulence/sediment/aggregation/sedimentation分类
资源环境引用本文复制引用
尹福玉,李旺,祖波,陈魏,王梅,张中杰,陈馨,李浩闻..微塑料在紊流中的聚沉行为[J].农业环境科学学报,2025,44(7):1836-1847,12.基金项目
重庆市水利科技重点项目(CQSLK-2023005) （CQSLK-2023005）
重庆市博士后研究项目特别资助项目(2023CQBSHTB1004) （2023CQBSHTB1004）
招商局生态环保科技有限公司科技自主创新项目(240128) （240128）
重庆交通大学科研启动经费项目(F1230105) （F1230105）
重庆市城市管理科研项目(城管科字2021第12号) Chongqing Water Conservancy Science and Technology Project(CQSLK-2023005) （城管科字2021第12号）
Chongqing Postdoctoral Special Funding Project(2023CQBSHTB1004) （2023CQBSHTB1004）
Scientific and Technological Innovation Project of China Merchants Eco-Environmental Protection Technology Co.,Ltd.(240128) （240128）
Research Funding Project of Chongqing Jiaotong University(F1230105) （F1230105）
Chongqing Urban Management Science and Technology Project(Chongqing Urban Management Sci-Tech No.12 of 2021) （Chongqing Urban Management Sci-Tech No.12 of 2021）
