Abstract:In this study, the sedimentation behaviors of polyethylene terephthalate (PET) microplastic in aquatic environment were investigated under various electrolyte concentration, electrolyte type, and pH conditions. The results indicated that PET microplastic sedimentation was significantly enhanced with electrolyte concentration, and the minimum standardized concentration (C/C0) was 0.64. The similar electrolytes showed similar impacts on PET microplastic sedimentation. However, compared with 1-1electrolytes (e.g. NaCl and KCl), the 1-2electrolytes (e.g. CaCl2 and MgCl2) remarkably improved PET microplastic sedimentation. PET microplastic sedimentation in aquatic environment was enhanced with decreasing pH. When pH values decreased from 10 to 4, the maximum C/C0 of PET microplastic suspension decreased from 0.98 to 0.76. The one-site kinetic settlement model well described PET microplastic sedimentation in aquatic environment. The tendency of DLVO results was consistent with the experimental results, which may reflect the sedimentation behaviors of PET microplastic. Findings from this work were useful on improving current knowledge of microplastic environmental behaviors and providing theoretical basis for environmental risk evaluation of microplastic.
Enfrin M, Dumee L F, Lee J. Nano/microplastics in water and wastewater treatment processes:Origin, impact and potential solutions[J]. Water Research, 2019,161:621-638.
[2]
王彤,胡献刚,周启星.环境中微塑料的迁移分布、生物效应及分析方法的研究进展[J]. 科学通报, 2018,63(4):385-395.Wang T, Hu X, Zhou Q. The research progress in migration, distribution, biological effects and analytical methods of microplastics[J]. Chinese Science Bulletin, 2018,63(4):38-395.
[3]
骆永明,周倩,章海波,等.重视土壤中微塑料污染研究防范生态与食物链风险[J]. 中国科学院院刊, 2018,33(10):1021-1030.Luo Y, Zhou Q, Zhang H, et al. Pay attention to research on microplastic pollution in soil for prevention of ecological and food chain risks[J]. Bulletin of Chinese Academy of Sciences, 2018, 33(10):1021-1030.
[4]
Jiang C, Yin L, Wen X, et al. Microplastics in sediment and surface water of West Dongting Lake and South Dongting Lake:Abundance, source and composition[J]. International Journal of Environmental Research and Public Health, 2018,15(10):2164.
[5]
Pivokonsky M, Cermakova L, Novotna K, et al. Occurrence of microplastics in raw and treated drinking water[J]. Science of the Total Environment, 2018,643:1644-1651.
[6]
杨婧婧,徐笠,陆安祥,等.环境中微(纳米)塑料的来源及毒理学研究进展[J]. 环境化学, 2018,37(3):383-396.Yang J, Xu L, Lu A, et al. Research progress on the sources and toxicology of micro (nano) plastics in environment[J]. Environmental Chemistry, 2018,37(3):383-396.
[7]
韩丽花,李巧玲,徐笠,等.大辽河沉积物中微塑料的污染特征[J]. 中国环境科学, 2020,40(4):1649-1658.Han L, Li Q, Xu L, et al. The pollution characteristics of microplastics in Daliao River sediments[J]. China Environmental Science, 2020, 40(4):1649-1658.
[8]
徐沛,彭谷雨,朱礼鑫,等.长江口微塑料时空分布及风险评价[J]. 中国环境科学, 2019,39(5):2071-2077.Xu P, Peng G, Zhu L, et al. Spatial-temporal distribution and pollution load of microplastics in the Changjiang Estuary[J]. China Environmental Science, 2019,39(5):2071-2077.
[9]
马乃龙,程勇,张利兰.微塑料的生态毒理效应研究进展及展望[J]. 环境保护科学, 2018,44(6):117-123.Ma N, Cheng Y, Zhang L, et al. Research progress and prospect of ecotoxicological effects of microplastic[J]. Environmental Protection Science, 2018,44(6):117-123.
[10]
廖苑辰,娜孜依古丽·加合甫别克,李梅,等.微塑料对小麦生长及生理生化特性的影响[J]. 环境科学, 2019,40(10):4661-4667.Liao Y, Nazygul J, Li M, et al. Effects of microplastics on the growth, physiology, and biochemical characteristics of wheat (Triticum aestivum)[J]. Environmental Science, 2019,40(10):4661-4667.
[11]
刘沙沙,付建平,郭楚玲,等.微塑料的环境行为及其生态毒性研究进展[J]. 农业环境科学学报, 2019,38(5):957-969.Liu S, Fu J, Guo C, et al. Research progress on environmental behavior and ecological toxicity of microplastics[J]. Journal of Agro-Environment Science, 2019,38(5):957-969.
[12]
刘治君,杨凌肖,王琼,等.微塑料在陆地水环境中的迁移转化与环境效应[J]. 环境科学与技术, 2018,41(4):59-65,90.Liu Z, Yang L, Wang Q, et al. Migration and transformation of microplastics in terrestrial waters and effects on eco-environment[J]. Environmental Science & Technology, 2018,41(4):59-65,90.
[13]
Cai L, Hu L, Shi H, et al. Effects of inorganic ions and natural organic matter on the aggregation of nanoplastics[J]. Chemosphere, 2018,197:142-151.
[14]
Li S, Liu H, Gao R, et al. Aggregation kinetics of microplastics in aquatic environment:Complex roles of electrolytes, pH, and natural organic matter[J]. Environmental Pollution, 2018,237:126-132.
[15]
Lu S, Zhu K, Song W, et al. Impact of water chemistry on surface charge and aggregation of polystyrene microspheres suspensions[J]. Science of the Total Environment, 2018,630:951-959.
[16]
Alimi O S, Budarz J F, Hernandez L M, et al. Microplastics and nanoplastics in aquatic environments:Aggregation, deposition, and enhanced contaminant transport[J]. Environmental Science & Technology, 2018,52(4):1704-1724.
[17]
Jodar-Reyes A B, Ortega-Vinuesa J L, Martin-Rodriguez A. Electrokinetic behavior and colloidal stability of polystyrene latex coated with ionic surfactants[J]. Journal of Colloid and Interface Science, 2006,297(1):170-181.
[18]
Oriekhova O, Stoll S. Heteroaggregation of nanoplastic particles in the presence of inorganic colloids and natural organic matter[J]. Environmental Science-Nano, 2018,5(3):792-799.
[19]
Oncsik T, Trefalt G, Csendes Z, et al. Aggregation of negatively charged colloidal particles in the presence of multivalent cations[J]. Langmuir, 2014,30(3):733-741.
[20]
Peng S, Wu D, Ge Z, et al. Influence of graphene oxide on the transport and deposition behaviors of colloids in saturated porous media[J]. Environmental Pollution, 2017,225:141-149.
[21]
Vikesland P J, Rebodos R L, Bottero J Y, et al. Aggregation and sedimentation of magnetite nanoparticle clusters[J]. Environmental Science-Nano, 2016,3(3):567-577.
[22]
Quik J T K, van de Meent D, Koelmans A A. Simplifying modeling of nanoparticle aggregation-sedimentation behavior in environmental systems:A theoretical analysis[J]. Water Research, 2014,62:193-201.
[23]
Petosa A R, Jaisi D P, Quevedo I R, et al. Aggregation and deposition of engineered nanomaterials in aquatic environments:Role of physicochemical interactions[J]. Environmental Science & Technology, 2010,44(17):6532-6549.
[24]
Wu L, Liu L, Gao B, et al. Aggregation kinetics of graphene oxides in aqueous solutions:Experiments, mechanisms, and modeling[J]. Langmuir, 2013,29(49):15174-15181.
[25]
Parvinzadeh M, Moradian S, Rashidi A, et al. Surface characterization of polyethylene terephthalate/silica nanocomposites[J]. Applied Surface Science, 2010,256(9):2792-2802.
[26]
Liu J, Ma Y, Zhu D, et al. Polystyrene nanoplastics-enhanced contaminant transport:Role of irreversible adsorption in glassy polymeric domain[J]. Environmental Science & Technology, 2018, 52(5):2677-2685.
[27]
华晶,袁晋,盛光遥.金属氧化物纳米颗粒在水环境中的团聚与沉降[J]. 环境科学与技术, 2016,39(3):17-22.Hua J, Yuan J, Sheng G. Aggregation and sedimentation of metal oxides nanoparticles in aquatic environment[J]. Environmental Science & Technology, 2016,39(3):17-22.
[28]
Su Y, Yang G, Lu K, et al. Colloidal properties and stability of aqueous suspensions of few-layer graphene:Importance of graphene concentration[J]. Environmental Pollution, 2017,220:469-77.
[29]
Wang M, Gao B, Tang D. Review of key factors controlling engineered nanoparticle transport in porous media[J]. Journal of Hazardous Materials, 2016,318:233-246.
[30]
吕雪艳,孙媛媛,施小清,等.环境因子对两种纳米金属氧化物在水体中稳定性的影响[J]. 农业环境科学学报, 2015,34(1):144-154.Lv X, Sun Y, Shi X, et al. Effects of environmental factors on stability of two metal oxide nanoparticles in aqueous medium[J]. Journal of Agro-Environment Science, 2015,34(1):144-154.
[31]
Li Q, Chen B, Xing B. Aggregation kinetics and self-assembly mechanisms of graphene quantum dots in aqueous solutions:Cooperative effects of pH and electrolytes[J]. Environmental Science & Technology, 2017,51(3):1364-1376.
[32]
Xia T, Fortner J D, Zhu D, et al. Transport of sulfide-reduced graphene oxide in saturated quartz sand:Cation-dependent retention mechanisms[J]. Environmental Science & Technology, 2015,49(19):11468-11475.
[33]
Saleh N B, Pfefferle L D, Elimelech M. Aggregation kinetics of multiwalled carbon nanotubes in aquatic systems:Measurements and environmental implications[J]. Environmental Science & Technology, 2008,42(21):7963-7969.