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

Key words: 
• PPCPs /
• conventional activated sludge /
• membrane bioreactor /
• advanced oxidation /
• wastewater treatment

Abstract: 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/H2O2 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.