Sources and quantities of main water pollution loads released into Three-Gorge Reservoir of the Yangtze River

The water quality and its changes of the Three-Gorge reservoir(TGR)are a hotspot after it begins to store water and generate electricity.About 11.1% of water inspecting sites exceed the required quality standards at present.The pollution belts exist in some shores by the urban zones.The main sources and quantities of water pollution loads(WPLs)released into TGR are analyzed by using the problem-oriented approach used in life cycle assessment.The results show that the eutrophic pollution loads(PLs)is 27 900 t PO₄^3- eq,in which COD_Cr accounts for 16.4%,the total nitrogen and phosphorus for 37.9% and 45.8%,respectively.The municipal sewages(MSs)and agriculture chemical fertilizers are the two biggest contributors,which account for 61.0% and 26.3% respectively.The freshwater aquatic ecotoxicity(FAETs)PLs is 7612.6 t 1, 4-dichlorobenzene eq,of which the contribution rates are 78.0% for volatilization hydroxybenzenes(VHs)and 21.2% for mercury.76.5% from MSs and 23.5% from main industrial enterprises(MIEs).The total eutrophic PLs,as well as the FAETs PLs of Cr⁶⁺ lead from MIEs,and VHs from MSs are increasing.