The Recognition And Analysis Of Water Pollution For Wangjiaba Reservoir

Environmental problems of rural drinking water sources in China is very serious,drinking water is not safe for population of 320 million,which accounts for 34%of the total rural population.In population of unsafe drinking water,there are 220 million people drinking unsafely,because the water quality does not live up to the standards,which accounts for 70%of the total unsafe drinking population.China’s economy is undergoing a period of rapid development,water pollution caused by the development is increasing.In the following period,pollution is still the leading factors affecting drinking water safety.According to the results of evaluation of surface water quality in China,there are 35.6%of the drinking water sources does not live up to the water function zoning standards,among which there are 44%of rivers,77%of lakes,23%of reservoirs below the standards.It will be a long way to go to let rural population drink cleaning water.Located in Maojiadian,Tucheng Xiang,Dianjun district of Yichang,Wangjiaba reservoir’s catchment area covers 27.5 square kilometers and it can hold 1697 ten thousand cubic meters.It is an irrigation-based reservoir,with comprehensive benefit for urban water supply.It is one of the centralized sources of drinking water in Dianjun district with the urban water supply of 90,000 cubic meters for 8200 people.Investigation group conducted water quality analysis for 11 points of Wangjiaba reservoir in April,July,and December separately.Currently,wangjiaba reservoir is inferior category V water quality,at medium eutrophication level.According to the survey,the agricultural non-point pollution of Wangjiaba reservoir consists of three main areas:runoff areal source,agricultural livelihood source,agricultural farming source.The sources of the Wangjiaba reservoir are systemically studied in this paper,including pollution forecast,environmental capacity calculation,pollution-control measures,and so on.Main results are as follows:(1)Agricultural non-point source pollutionThe agricultural non-point pollution of Wangjiaba reservoir consists of runoff areal source,agricultural livelihood source,and agricultural farming source.The agricultural nonpoint source pollution’s total quantity is COD:116.04t/a,TN:15.67t/a,TP:3.06t/a.The livelihood source produces the most,runoff areal source is second,and the rainfall produces less.(2)Environmental capacity and total pollutant discharge amountWangjiaba reservoir is a relatively closed medium and small reservoir,reservoir inflow mainly comes from rainfall,runoff and groundwater recharge;released water is mainly used for irrigation,flood discharge and energy generation.Annual released water quantity is 2.4.36×107m3/a;annual water inflow is 2.418X 107m3/a.According to the calculation,the environmental capacity for COD is 635.31t/a,TN is 16.7 t/a,TP is 3.5 t/a.80%of the environmental capacity can used as environmental capacity,and the rest can be reserved.TN need to reduce 2.31 t/a,a reduction ratio of 15%.TP need to reduce 0.228t/a,a reduction ratio of 7%.(3)Engineering measures for water purificationAccording to the actual situation,wastewater collection and treatment need to be carried out in the Xiaoshimen,Laolinkou,Xiangiialing,and Huangiialing.Using artificial wetland technology for sewage treatment is a relatively centralized mode.It will need 5 artificial wetlands,with an area of 400-700m2.Daily processing capacity is 200-350t.The garbage collection of the five villages can also play an important role in environment protection.(4)Management measuresThere are many orchard and tea garden in Wangjiaba reservoir catchment.Excessive use of pesticides and chemical fertilizers can runoff into the reservoir and led to pollution Therefore,the use of pesticide and chemical fertilizer must be reasonable cut.The technology of fertilizer and Human and animal manure technology must be made greater efforts to.In addition,farming pollution is also one of the important reasons.The comprehensive utilization of livestock waste wastewater,such as edible fungi and biogas,can effectively reduce pollution,the use of stabilization pond can also be considered as a harmless treatment for aquaculture wastewater...