摘要
纳米材料的水环境行为受自身理化性质和水体理化性质的影响.模拟实际水环境条件下不同纳米材料的吸附、聚沉行为对理解纳米材料的潜在生态风险具有重要意义.本研究以管径为4—6 nm(MWNTs-1)和10—20 nm(MWNTs-2)的羧基化多壁碳纳米管(MWNTs-COOH)为研究对象,系统研究了腐殖酸(HA)在MWNTs-COOH表面的吸附特征,并利用拉曼光谱对MWNTs-COOH吸附HA前后的变化进行了表征.结果表明,HA在MWNTs-1和MWNTs-2表面的最大吸附量分别为139.6 mg·g^-1和101.2 mg·g^-1,且随pH增加而降低;HA在MWNTs-COOH表面的吸附在前24 h增长较快,72 h达到吸附平衡;HA对MWNTs-COOH在溶液中的悬浮/沉降性能具有显著影响;管径更小、比表面积更大的MWNTs-1碳堆积结构更紊乱,缺陷更多,HA的吸附会覆盖MWNTs-COOH表面的缺陷.本研究有助于更好的掌握不同形貌纳米材料在实际水体环境中迁移、转化、归趋等环境行为,为科学评估纳米材料潜在生态危害提供理论依据.
Environmental behavior of nanomaterials in water was greatly affected by their own Physical and chemical characteristics of water.Understanding the adsorption and sedimentation behavior of nanomaterials with different morphology in real aquatic consist of great importance to reveal the potential ecological risks of nanomaterials in aquatic environments.In this study,the adsorption isotherm and kinetics of humic acid(HA)on the surface of MWNTs-1(4—6 nm)and MWNTs-2(10—20 nm)and effect of HA on suspension/sedimentation behavior were studied.The change of Raman spectroscopy of MWNTs-COOH before and after adsorbed HA was studied.The result indicated that the adsorption amount of HA gradually decreases with the increasing of solution pH.The maximum adsorption amount of HA on MWNTs-1 and MWNTs-2 was 139.6 mg·g^-1 and 101.2 mg·g^-1,respectively.The study of adsorption kinetics showed that the adsorption of HA on MWNTs-COOH increased rapidly in the first 24 hours and reached the adsorption equilibrium in 72 hours.HA had a significant effect on the stabilization properties of MWNTs-COOH in solution.MWNTs-COOH with smaller diameter and larger specific surface area had more disordered carbon accumulate structure and more defects,and the adsorption of HA could reduce the surface defects of MWNTs-COOH.This study was conducive to a better understanding of environmental behaviors of migration,transformation and reorientation of nanomaterials with different morphology in the actual water environment,and provided a theoretical basis for scientific assessment of potential ecological hazards of nanomaterials.
作者
方梦园
赵天慧
赵晓丽
汤智
武迪
吴丰昌
FANG Mengyuan;ZHAO Tianhui;ZHAO Xiaoli;TANG Zhi;WU Di;WU Fengchang(Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming,650500,China;State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing,100012,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第10期2897-2906,共10页
Environmental Chemistry
基金
国家杰出青年科学基金(41925031)
国家自然科学基金(重大项目)(41991315)资助
关键词
碳纳米管
腐殖酸
吸附
悬浮/聚沉
拉曼光谱
multi-walled carbon nanotubes(MWNTs)
humic acid
adsorption
suspension performance
raman spectrum
作者简介
通讯联系人:汤智,Tel:010-84531804,E-mail:tzwork@hotmail.com
