污水处理中几种去除药物及个人护理用品方法的机理及效果比较

目前广泛分布在环境中的药物及个人护理品（pharmaceuticals and personal care products, PPCPs）在环境中的迁移、转化和处理已成为环境科学与工程研究的一个新的领域。污水处理厂排水是PPCPs进入环境中的主要途径。介绍了污水处理过程中传统活性污泥法、膜处理技术以及氧化处理等主要工艺对PPCPs的去除机理，并对去除效果进行了比较。以传统活性污泥法及在其改进后的膜处理技术为基础的大部分现有污水处理厂只能够去除一部分PPCPs，并且主要通过吸附（如对于吐纳麝香、佳乐麝香、萨利麝香等脂溶性较高的有机物）和生物降解作用（如对于布洛芬，17β-雌二醇，雌酮等易反应的有机物）。然而，吸附了PPCPs的污泥通过土壤施肥又将PPCPs带入土壤中，进而会渗滤到地下水，或随径流水进入地表水中。因此，PPCPs并没有从根本上得以去除。相比之下氧化处理工艺（如氯化、臭氧氧化、紫外辐射）或这些工艺的组合能够将大部分的PPCPs进行氧化，去除效果明显优于以上2种技术。然而，氧化后产物的种类和毒理性需要更深入的研究。

Mechanism and efficiency comparison between techniques of removing pharmaceuticals and personal care products in wastewater treatment

Pharmaceuticals and personal care products (PPCPs) have been widely found in the aquatic and terrestrial environments all over the world. Their environmental fate and impacts are emerging issues. Effluent from wastewater treatment plants into the aquatic environment is a significant pathway of releasing PPCPs in the environment. In this article, we reviewed recently published works regarding the mechanism of removing PPCPs during wastewater treatment processes, which mainly include conventional activated sludge, membrane filtration, and advanced oxidations, and compared the removal efficiency. Conventional biological reactors and membrane reactors are only able to remove a limited number of PPCPs maily depending on sludge sorption ( e. g. , tonalide, galaxolide and celestolide) and microorganism degradation (e.g. , ibuprofen, 17β-estradiol and estrone). However, sludge-sorbed PPCPs were not removed basically and could potentially enter the soil via land application of the sludge as plant fertilizers, then go into groundwater and surface water by leaching and runoff. Advanced post-treatment techniques such as chlorination, ozone, UV, UV/H_2O_2 or their combinations are able to remove PPCPs more efficiently than the conventional activated sludge and membrane. But the toxicity of the oxidation products of PPCPs is a complex problem and requires further study.