Analysis of Emerging Contaminants in Surface Water, Aquaculture Ponds and Wastewater Treatment Facilities in the Taige Canal Basin

Emerging contaminants(ECs) have aroused great concerns due to their widespread presence as well as their potential health and ecological risks. Currently monitoring data about ECs in Chinese rural areas are still limited. In this study, Taige Canal basin was selected as a typical rural area for a pilot study. The occurrence of ECs, including pharmaceutical and personal care products(PPCPs), pesticides, plasticizers and flame retardants, in surface water and aquaculture ponds, as well as in wastewater treatment facilities, was comprehensively investigated. The effectiveness of rural decentralized wastewater treatment facilities and centralized wastewater treatment plant(WWTP) in removing ECs was also analyzed. Among 126 commonly used pesticides for target analysis, 25 compounds were detected in surface water with high frequency of >80%. Besides, 55 PPCPs, 21 pesticides and 18 other industrial products were identified by non-target analysis using high resolution mass spectrometry(HRMS). Totally 18 compounds were detected in surface water with a frequency of >60% and 6 of them were found in all samples, including irbesartan, valsartan, propazine, buprofezin, bis(2-ethylhexyl) phthalate(DEHP) and tri-(2chloroisopropyl) phosphate(TCPP), with mean concentrations of 3022, 195, 125, 218, 3738 and 545 ng/L, respectively. There are 29 compounds(11 PPCPs, 8 pesticides and 10 other industrial products) detected in water samples from the aquaculture ponds, of which 13 compounds were found in all three ponds. The removal efficiencies of ECs in wastewater treatment facilities are generally limited, except valsartan(82%-86%), nobiletin(100%) and diisodecylphthalate(100%) were found to be significantly removed.