Contaminants of emerging concern in landfill leachate in China: A review

Abstract

Abstract This review paper summarizes the occurrence, removal and ecological risk of contaminants of emerging concern (CEC) reported in landfill leachate in China since 1996 (43 studies in 10 regions). Results show that many more studies are conducted in developed southeastern China than in developing western and northeastern regions in China. Phthalate esters (PAEs, with 15 studies) and pharmaceuticals and personal care products (PPCPs, with 13 studies) are the two most frequently studied CEC classes. Concentrations of nine CECs classes were in a wide range from 0.03 (organochlorine pesticides) to approximately 4500 μg/L (alkylphenol polyethoxylates/bisphenol analog). Meanwhile, concentrations of CEC compounds range from below detection limit (e.g. doxycycline) to approximately 4500 μg/L (bisphenol A). Several PAEs (diethyl phthalate, di-n-butyl phthalate, and di (2-ethylhexyl) phthalate) and PPCPs (diclofenac and gemfibrizol) have significant variation between sampling sites. Typically, advanced treatment processes can achieve higher removal efficiencies of CEC compounds from landfill leachate compared with conventional treatment processes. Furthermore, environmental risk assessments of CEC compounds in treated landfill leachate using a risk quotient method show that 2 (substituted) polycyclic aromatic hydrocarbons (sPAHs) (benzo(a)anthracene and benzo(b)fluoranthene), 2 PPCPs (bezafibrate and sulfapyridine), γ-hexachlorocyclohexane, and bisphenol A pose high risk. The importance of monitoring and potential risks of CECs in the leachate to vicinity aquatic environment cross China is addressed.