Toxicity characteristics of sewage treatment effluents and potential contribution of micropollutant residuals

摘要: A typical sewage treatment plant is designed for organic and nutrient removal from municipal water not targeted to eliminate micropollutants such as pesticides, pharmaceuticals, nano-sized metals which become a big concern sustainable human ecological system are mainly discharged plant. Therefore, despite contaminant by wastewater processes, there still remaining environmental risks untreated pollutants in STP (sewage plant) effluents. This study performed aquatic toxicity tests of raw treated effluents two plants evaluate reduction process analyze concentration contaminants reveal potential toxic factors Water samples were collected each steps STPs, acute chronic conducted following USEPA (United States Environmental Protection Agency) OECD (Organization Economic Cooperation Development) guidelines. Endpoints immobility mortality reproduction effect estrogenicity. Acute EC50s (median effective concentration) influents Seungki (SK) Jungnang (JN) STPs 54.13 ± 32.64% 30.38 ± 24.96%, respectively, reduced 96.49 ± 7.84% 100%. was clearly correlated with SS (suspended solids) because filter feeding characteristics test organisms. Chronic revealed that lethal low showed higher number neonates. However, related removal. Fecundity positively increased compared wastewater, no significant differences observed the control group JN final effluent implying effects estrogenic compounds Conventional some organics nutritional it results positive reproductive but showing correlation. Unknown could be reason causing increase brood size. suggests pharmaceutical residues nanoparticles one major underline factors.