Study For Aquatic Ecological Risk Assessment Of Typical Emerging Contaminants

Psychoactive substances that were identified emerging contaminants have received extensive attention by society.A large amount of psychoactive substances were manufactured and used in recent years.Because of the low removal rate in sewage treatment plants,most psychoactive substances entered natural water bodies with the effluent.Due to the polarity and biological properties of psychoactive substances,they are not easily degraded in natural water bodies and may cause harm to humans and aquatic organisms.The concentrations of psychoactive substances in surface water have been reported a lot,but researches on the aquatic toxicity effects and ecological risk assessment of psychoactive substances were quite limited.In this study,triphenyl phosphate?TPP?was chosen as a typcal emerging contaminat for the study of ecological risk assessment methord.Two typical psychoactive substances,methamphetamine?METH?and ketamine?KET?,were selected based on the status quo of psychoactive drug contamination in China's surface waters,and toxicity effect to aquatic organism in different trophic levels and ecological risk were studied.The main results were as below:?1?Based on the current ecotoxcity data screening methord,acute toxicity data with endpoin of survival and chronic toxicity data with endpoint of growth,reproduction,biochemistry and molecular biology were collected according to the reliability,relevance and accuracy,and species sensitivity distribution curves were construced.It was found that chronic toxicity fitness such as growth,reproductive,biochemistry and molecular biology were more sensitive to TTP,and the chronic harmed concentration to 5%species?HC₅?was5.84?g·L^-1.Multi-level ecological risk assessment of TPP in major surface waters in China was conducted using hazard quotient?HQ?and probabilistic ecological risk assessment?PERA?.The results showed that the risk quotients calculated based on acute and chronic toxicity data were all less than 0.1.The impact of TPP in surface water on the chronic toxicity of reproduction and growth of 0.1%to 1%aquatic organisms in China is 3.44%and 0.11%,respectively,and the ecological risk was low.?2?Chronic toxicity effects of KET and METH on three aquatic organisms were studied and multi-level ecological risk assessment was conducted to assess the potential risk of KET and METH in Chinese surface waters.The results showed that the no observed effect concentration?NOEC?of KET and METH for Oryzias latipes,Daphnia magna,and Soirodela polyrhiza was 10?g·L^-11 and 50?g·L^-1,10?g·L^-1 and 10?g·L^-1,50?g·L^-1 and10?g·L^-1,and the predicted no-effect concentration?PNEC?derived with assessment factor of 5 was 0.66?g·L^-1and 1.86?g·L^-11 respectively.The HQs of KET and METH calculated with environmental concentrations from 7 waters showed a low risk?HQ<1?.PERA results of KET and METH indicate that,0.18%⁰ and 13.13%².10%of surface waters in China were predicted to pose risk to chronic fitness with 0.1%¹%species affected,so METH have higher risk than KET.