| Xi'an cultural tourism moat is an important component. Because of natural and human factors, together with nonstandard rainwater sewage discharge make Xi'an moat water pollution, water quality deterioration. Therefore, it is necessary to prevention and control of water pollution causes and moat for city are studied, and the river restoration and improvement of environmental quality to provide scientific guidance. This paper will be used in the actual theory research, and through the field investigation and in-situ water and environmental assessment of the testing method of combining the moat section water pollution situation of full system research and puts forward practical, effective, convenient in economic management control approach scheme. Researching the main research results are as follows:(1)Analyzes the cause of the water- pollution causes in Xi'an moat. The results show that water in the vast majority of Xi'an moat time and sampling points were more than the standards of the surface water quality V class, exceeding by 178.63%. Basically can't achieve landscape water standards; Pollution mainly is non-point source pollution given priority to, with the dry season, with rain rainy season mainly pollutants into pollutants give priority to, its confluence of pollutants more, and it easy to cause the pollution of river body; The moat which generally high COD index with moat points of special river peripheral environment and contamination source closely related, and the total nitrogen, ammonia nitrogen and phosphorus with the season and the space index changes are obvious, the vulnerable, the influence of temperature and rainfall during the rainy season total nitrogen than 10mg/L, ammonia nitrogen than 8mg/L, total phosphorus more than 1.2 mg/L, showed obvious pollution features. (2) From space view, the moat's water quality conditions followed: HepingGateâ†'JianguoGateâ†'WenchangGateâ†'SouthGate, water qualityis good for landscape.SouthGateâ†'XiaonanGate, water quality becoming poor, WenchangGate started to get worse after the water began to extreme water quality change rule. From the time view, moat eutrophication index with the season variety are relatively obvious, the spring index rose slightly, summer start of rainfall, vulnerable the dual positive-negative role and filling causing water quality fluctuations, generally present summer water quality is bad, autumn water began to turn good trend.(3) Overflow natural after oxygen is improving an important way of dissolved oxygen in moat, upstream oxygen deficient value and plunge to after oxygen efficiency depth has great influence on the flow of the dam body, through flushing action can be reduced by 5% average 8% pollutants. Internal pollution downstream 10 - happens at dam as place. The main reason is: water flows from the dam, using upper and lower dam, formed the elevation difference of the upstream river sediment downstream scouring, can be accumulated sediment downstream, sediment, humus, microbial wait flush rise, formed a vertical and scouring the speed of the water, and further formed the vector upward trend of water diffusion of sediment, is caused extremely easily the secondary pollution.(4) Use the simple sum of water quality can be obtained: the evaluation method in Xi'an moat respectively weights pollution that: COD > total nitrogen > ammonia nitrogen > phosphorus.(5) Provide improvement and eliminate moat water environmental pollution engineering measures... |
PDF Full Text Request