The Evaluation Water Pollution And The Research Of Its Control For Wei River Of Shaanxi

Based on the Statistics Almanac of Shaanxi and the Environmental Statistics Almanac of Shaanxi in 1991-2002 as data source, referring to the related parts monitoring materials of from Shaanxi Environment Protection Bureau, by means of statistics and analysis of those data, according to the water evaluation criterions for the surface water environmental quality that state published in 2002 (GB3838-2002), using parameter on DO, potassium permanganate, BOD, NH3-N, volatile hydroxybenzene and petroleum, this paper has studied the water pollution processes and controls of 13 parts of the Wei River reach in Shaanxi systematically and concluded as follows: 1. By means of the system analysis to parameter on DO, potassium permanganate, BOD, NH3-N, volatile hydroxybenzene and petroleum, the water pollution status quo Wei River reach in Shaanxi has been researched, classified and assessed. And the conclusion is that the integration indices are all worst â…¤except from the part of Linjia village that account for 78% in all parts monitored, which is polluted seriously. 2. The analysis of the pollution indices at the times of abundant water, mean water and insufficient water shows that the ratio of the worst â…¤in all parts in insufficient water time is much higher than that in sufficient water, of which the index of potassium permanganate reached to the worst â…¤account for 61.2% of the control length of the river in insufficient water time, yet 30.2% in sufficient water time. The primary reason is that the amount of ecological water lessen and the ability to clean themselves is lower in insufficient water time. 3. The studies of the sources of pollutants in different parts in Wei River of Shaanxi show that the non-point pollution source causes NH3-N pollution, of which NH3-N account for 76.54% and for 23.64% from the point pollution sources. The pollution of potassium permanganate was caused by the point pollution sources mainly, e.g. the waste water from factories and urban families. 4. Based on the history of 10-year-pollution in this area, by means of the math prediction models, the possible tendency of water pollution in future 10 years. 5. Finally, according to the results of analysis and prediction, the methods of Wei River water pollution control and reach ecological repair have been suggested.