Pollutant Load Allocation And Management In Xi’an-xianyang Section Weihe River

In recent years, with the development of China’s economy, environmental pollution has started to restrict society’s development and progresses. Since pollutant total amount control system was introduced to China in the1980s, a lot of reseaches were used to establish a total amount control technical system. But some problems were affected the total amount control effect, for example the uncertainty of the corresponding response relationship between the pollution sources and water quality, the single effect of allocation method and so on. Weihe River is the largest tributary of the Yellow River. The water quality is serious. Xi’an and Xianyang City located in the middle and lower reaches of the Weihe River which had larege population. Lots of industrial enterprises focused on the river sides and pollutants caused serious pollution.Therefore, this article based on total amount control theory, intended to establish the relationship from the source to the end,"source of pollution-sewage outfalls-monitoring sections", as well as the response relationship between pollutants and the water quality. On this basis, this article established the multi-level waste load allocation method and allocated total load respectively into the regions level and the enterprises level. Finally, environmental management programs were proposed for total amount control.First this article has established the response relationship between pollutants and the water quality by using one-dimensional water quality model. The average error of simulation results based on the average annual flow condition was16.30%, followed by the simulation results based on the dry season condition and the wet season condition. The overall simulations were able to meet this study needs.Second, this article intended to establish a multi-level load allocation system including two levels. In the regional level, using the Gini coefficient and the entropy weight method allocated the load into districts and counties, taking social, economic and environmental factors into consideration. And then in the enterprises level based on the principle of efficiency, optimal generation performance standard (GPS) method was used to improve the emission performance. The model’s objective was to maximum the enterprises value and strived to minimum environmental cost. Took Xi’an and Xianyang City for example for COD allocation, Xi’an City totally reduced3360.57tons, Xianyang City total reduced1518.14tons; Xi’an City had eight key cutting areas and Xianyang City had six. The maximum reduction rate was20%, the minimum was1%. In the enterprises level, the areas reduction rate were less than10%would reserve some pollution load for future development.Finally, this article established management program which included economic measures and management measures to regulate the sources of pollution. Economic measures took emissions trading policy for example and discussed how to establish the primary and secondary trading markets in Xi’an-Xianyang section.