老化方式对聚苯乙烯与阿米替林吸附性能的影响

Effect of aging method on the adsorption properties of polystyrene and amitriptyline

选择聚苯乙烯(PS)和阿米替林(AMI)作为研究对象,对PS进行紫外照射和高温老化.采用扫描电镜、氮气吸脱附、接触角测试和红外光谱对老化前后PS进行了表征,研究了老化前后PS对AMI的吸附动力学、等温吸附和盐度的影响(天然海水、模拟海水、纯水),探究了不同老化条件对PS吸附性能的影响.结果表明:两种老化方式均使PS的粒径变小,表面出现凹坑、褶皱和孔隙,比表面积和含氧官能团量增加,以紫外老化PS更为明显.老化后PS对AMI的吸附速率较原始PS有所提高,动力学过程符合准二级动力学和颗粒内扩散模型,吸附过程以颗粒内扩散和表面吸附为主.两种老化方式均导致PS对AMI的吸附量增加,高温和紫外老化后PS对AMI的最大吸附量分别是原始PS的1.24和1.33倍,等温吸附线符合Freundlich模型,表明PS对AMI存在多层吸附,老化能增强PS的亲水性和表面官能团量,提高其对亲水性有机污染物的吸附能力.不同背景溶液中,老化PS对AMI的吸附能力为纯水>模拟海水>天然海水,表明PS对低盐环境中AMI具有更强的负载能力,更易引起污染物的迁移和扩散.

Polystyrene(PS)and amitriptyline(AMI)were used as the target pollutants,and PS was subjected to ultraviolet irradiation and high temperature aging.The original and aged PS were characterized by scanning electron microscopy,N2 adsorption-desorption isotherms,contact angle and FTIR analysis.The adsorption kinetics and isotherm of PS for AMI were studied,and the effect of aging methods on the adsorption performance of PS was discussed.The results showed that both aging methods reduced the particle size of PS,and numerous pits,wrinkles and pores were generated on the surface.The specific surface area and the number of oxygen-containing functional groups were increased,especially for UV-aged PS.The adsorption rate of AMI on aged PS was higher than that of original PS,and the kinetics could be well fitted by the pseudo-second-order kinetics and intraparticle diffusion model,suggesting that the adsorption process was dominated by intraparticle diffusion and surface adsorption.Both aging methods enhanced the adsorption of PS for AMI,and the adsorption capacities of AMI on high temperature and UV aged PS were 1.24 and 1.33 times that of the original PS,respectively.The adsorption isotherms conformed to the Freundlich model,indicating multilayer adsorption of AMI.The hydrophilicity and surface functional groups of PS were increased by aging,which improved the adsorption capacity for hydrophilic organic pollutants.In different background solutions,the adsorption capacity of aged PS for AMI varied with the following order:pure water>simulated seawater>natural seawater,indicating that PS had a stronger adsorption capacity for AMI in low salt environment and was more likely to cause the migration and diffusion of pollutants.