摘要
Abstract
To evaluate the influence of factors such as the aging effect on the adsorption-desorption of heavy metals by microplastics(MPs),the adsorption-desorption behaviors of heavy metal cadmium(Cd2+)by three different MPs(polypropylene(PP),polystyrene(PS),and polyvinyl chloride(PVC))under the aging effects of ultraviolet light(UV)and Fenton reagent were systematically studied.The results showed that both aging methods made the surfaces of PP,PS,and PVC microplastics rough,with cracks and wrinkles generated,the specific surface area increased,the oxygen-containing functional groups increased,and the O/C value increased;As the particle concentration of MPs increased from 0.5 g/L to 5.0 g/L,the unit adsorption capacities of the three types of MPs for Cd2+decreased by 79.41%,83.57%,and 83.49%respectively;The adsorption coefficient KF showed that the adsorption binding ability was PVC>PS>PP,and the values of the adsorption index 1/n were all in the range of 0＜0.3692～0.4406＜1,indicating that the adsorption of Cd2+on MPs was relatively easy to occur,and with the increase of the initial concentration of heavy metal Cd2+,the adsorption trend gradually slowed down;The aging treatment enhanced the adsorption capacity of MPs for Cd2+,and the results were Fenton>UV>original;The desorption amounts of PP,PS,and PVC for Cd2+under simulated gastric acid and simulated acidic environments were higher than those under the simulated water environment before and after aging.This study can provide an important scientific basis for comprehensively understanding the adsorption-desorption behaviors of heavy metals by aged MPs in the environment.关键词
微塑料/重金属/老化/吸附-解吸Key words
microplastics/heavy metal/aging/adsorption-desorption分类
资源环境
