Analysis Of The Pollution Situation Of The Zijiang River And The Countermeasures

This article focuses on the Zijiang River Basin,one of the four rivers in Hunan,as a research object.By referring to the literature and data to understand the history,humanities and nature of the Zijiang River Basin.At the same time,it summarizes and combines relevant domestic and foreign experience to find out the problems and causes of Zijiang River Basin.To strengthen the management and protection of rivers,it proposes corresponding countermeasures to build an ecological barrier of "one lake,three mountains and four waters" and promote ecological civilization.,To provide a basis for decision-making to build a beautiful Hunan.The Zijiang River Basin has a warm and humid climate and abundant rainfall.The economic and social development,land resources,and the characteristics of floods and water resources in the areas along the Zijiang River Basin.The utilization methods of the Zishui shoreline are diverse.Estuaries,bridges,ports,docks,river blocking facilities,landscape projects,etc.This article mainly investigates and counts the utilization of ports,bridges,and hydropower stations.Among them,there are 8 main ports,38 bridges under construction and have been built,and 10 hydropower stations.Through investigation and sampling of the entire river basin,the main sources of pollution in the Zijiang River Basin include industrial pollution,urban domestic sewage,breeding pollution and agricultural non-point source pollution.Among them,industrial pollution mainly focuses on antimony pollution investigation.There are 13 antimony-related enterprises in the Zijiang River Basin.The total antimony pollution site area is about 1.989 million m2,the amount of leftover waste residue is about 53.3 million m3,and the antimony discharge in percolated water is about 15,000 kg / a.There are 12 sewage plants built in the Zijiang River Basin,with an annual sewage treatment capacity of 500,000 tons.The overall effluent standards are Class B standards.There is still a large amount of urban domestic sewage discharged directly into the river without treatment,causing watershed pollution.Livestock and poultry farming waste utilization rate is low.There are a large number of small livestock and poultry farmers,and some farmers have not built facilities for collection,storage,treatment and utilization of manure that are fully compatible with the prevention and control of breeding pollution.Livestock and poultry manure cannot be fully utilized or harmlessly treated to meet discharge standards.At the same time,due to market price fluctuations,some farmers are unable to invest in manure treatment facilities due to surpluses and surpluses,and direct pollutant discharge exists.Agricultural non-point source pollution has a greater impact on the Zijiang River Basin,especially in the rural areas of farmland areas where pesticides and fertilizers are used in high amounts and the utilization rate is low.A large amount of residual pollution enters Zishui with rainfall,irrigation and surface runoff.The concentration of nitrogen and phosphorus in the water is relatively high.According to the water quality monitoring results,the water quality of Zishui Basin is generally excellent.Among the 44 monitoring sections,43 were Class I-III water quality and one was Class IV water quality.The cross-sectional ratio of excellent water quality(category Ⅰ～Ⅲ)is 97.7%.Among them,the proportion of main water grades Ⅰ to Ⅲ was maintained at 100%,the tributary Zhixi River section had excessive ammonia nitrogen and total phosphorus,and the section water quality was grade Ⅳ.Through the preliminary investigation and analysis,this article believes that in order to improve the pollution situation of the Zijiang River Basin,the following suggestions and countermeasures are proposed:(1)Pay attention to water resources protection,control the total amount of water used,and advocate citizens to save water.(2)Strengthen the management of the shoreline of the water area,conduct special clean-up of the four chaotic behaviors,and regulate the sand mining behavior of the river.(3)Industrial wastewater,especially antimony-containing enterprise wastewater,must be discharged before reaching the standard.The urban and rural domestic sewage shall be concentrated and then discharged;the urban and rural black and smelly ditch shall be specially treated.Steadily promote the pollution control actions of livestock and poultry farming,strictly implement the district management system of livestock and poultry farming,shut down or relocate all livestock and poultry farms(households)in the forbidden zone within 500 meters on both sides of the main stream of the water supply,and relocate the retired sites Clean up and restore the ecological environment on a field-by-house basis,and restore the ecological environment;scattered small-scale farmers carry out the combination of breeding and breeding,adopt biogas digesters,compost return to the field,organic fertilizer and other modes to realize the resource utilization of livestock and poultry breeding wastes to ensure that the farming manure is not discharged.Implement the zero-growth action of chemical fertilizers and pesticides,reduce the use of chemical fertilizers year by year;promote the comprehensive utilization of agricultural wastes.(4)Speed up the restoration of the water environment and the restoration of aquatic ecology.Actively carry out toilet revolution and manure treatment,step by step to promote rural domestic sewage treatment,and further promote rural domestic garbage management.Optimize water resources scheduling,improve natural connectivity of water bodies,and enhance self-purification capacity of water bodies.Strengthen the comprehensive control of soil erosion,improve aquatic habitats,restore biodiversity and restore ecological restoration on both sides of the river basin.