Distribution,Ecological Risk,Flux And Source Of Typical Emerging Contaminants In The Jilin Songhua River

Contaminants of emerging concern?CECs?have been in the environment at low concentrations for a long time,but the occurrence and potential ecological risks are discovered recently.Although these contaminants can pose potential risks to human health and the ecological environment,the concentration level,frequency,or source of these in the environment is unknown.In recent years,it has been reported that various CECs have been detected in wastewater treatment plants?WWTPs?,river water,river sediments,farmland,groundwater,and even drinking water.However,as the third largest river in China,the study on CECs in the Songhua River is rarely reported,especially the study in the Jilin Songhua River.Jilin province is a major province in agriculture and animal husbandry as well as a province with a strong momentum of development in the pharmaceutical industry.Therefore,it is of great significance to study the typical CECs in Jilin Songhua River.In this study,typical pharmaceuticals,active ingredients of personal care products and natural estrogens were selected as the target CECs.The occurrence and distribution of typical CECs in river water and sediments in Jilin Songhua River;tributary river water in Huifa River,Yinma River and Yitong River;effluents in Jilin and Songyuan WWTPs were determinated by liquid chromatograph-mass spectrometer?LC/MS-MS?.Risk quotient was used to evaluate the potential aquatic ecological risk of typical CECs;the monthly fluxes of CECs in the tributary river water,their upstream and downstream river water were calculated;principal component analysis?PCA?was used to determine the possible sources of CECs in the mainstream river water;and the apportionment calculation is used to evaluate the contributions of major tributary rivers and Jilin and Songyuan WWTP effluents to the Jilin Songhua River.The results showed that the concentrations of estriol,doxycycline and caffeine were higher.The maximum and median concentrations of estriol were 27.4 ng L^-1 and14.3 ng L^-1 in spring,26.9 ng L^-1 and 18.5 ng L^-1 in summer,and 29.4 ng L^-1 and 21.5ng L^-1 in autumn.The maximum and median concentrations of doxycycline were 20.6ng L^-1 and 7.9 ng L^-1 in spring,15.3 ng L^-1 and 1.7 ng L^-1 in summer,and 32.9 ng L^-1and 9.3 ng L^-1 in autumn.The maximum and median concentrations of caffeine were11.8 ng L^-1 and 4.8 ng L^-1 in spring,26.3 ng L^-1 and 6.8 ng L^-1 in summer,and 19.3 ng L^-1 and 6.0 ng L^-1 in autumn.The total concentration of these targets contaminants in the mainstream water in autumn is about 1.5 times than those in summer,and the total concentration of targets contaminants in the mainstream water in spring is about 1.4times than those in summer.The concentration of targets contaminants is higher in the polluted tributaries river water and the river water near the outlet of WWTPs.The risk assessment results showed that the maximum risk quotient of estrone in the mainstream water was 1.07,and the maximum risk quotient of estriol in the effluents of WWTPs was 2.10.Erythromycin,doxycycline,lincomycin,estrone and estriol in the mainstream,tributary river water and WWTPs effluents all posed the medium or high risks.The monthly fluxes of the CECs in the downstream river water of Jilin WWTP is136.9 kg month^-1,followed by 116.5 kg month^-1 for the CECs in the downstream river of Yinma River and Yitong River.The results of PCA showed that the CECs in the mainstream river water may come from the WWTP effluents,aquaculture,animal husbandry and agricultural activities;and untreated domestic sewage.In spring,the major contribution of targets contaminants in the mainstream results from its tributaries,contributing more than 50%.The research on the distribution,ecological risk,flux and source of typical CECs in Jilin Songhua River is carried out.The result provides the local decision makers with a scientific basis and technical support in the management of these contaminants in the Songhua River.