Research On Dynamic Assimilative Capacity And Water Quality Management Of Tao River In Yangquan

Yangquan is an emerging industrial city that pioneers in comprehensive urbanization in Shanxi,and enjoys the reputation as the hometown of coal,which contributes in a great proportion to Shanxi‘s economic development.Nevertheless,along with the expansion of local coal mines and petrochemical enterprises,larger amount of polluted and waste water has been discharged into the Tao River,which has been beyond Tao River's self-cleaning capacity and made the water quality poor.As mother river of Yangquan,Tao River exerts an irreplaceable effect towards the overall development of Yangquan.Although Tao River valley is abundant with water resource,water resource that could be directly applied in life or realizing economic value is in scarcity.Apart from geographical factors and irrational exploitation & development,water pollution is another major reason.Changes of water quality have direct influence on assimilative ability,while assimilative ability could affect the governance of pollution source in sewage draining exits,which could also change water quality management decision-making.Therefore,through exploring the assimilative ability of rivers and the dynamic variation pattern,it could function as a reference to formulate feasible control program of discharging pollution into the river and recover the water quality of Tao River by reasonably utilizing the river's regulating ability.It provides significant guidelines for protecting the local water resources and improving the water ecology and water environment in Yangquan City.For the objective of exploring Tao River's assimilative ability,providing feasible pollution discharge control program and analyzing the research mechanism of urban rivers' assimilative ability both at home and abroad,this paper takes the Tao River in Yangquan as the research subject and the river's hydrology change as the starting point,evaluates the current situation of surface water quality and investigates as well as assesses the pollution discharge exits on the basis of normal supervising data in accordance with water quality preservation goal.By applying the one dimensional water quality model of river,pollution source is concentrated.This paper analyzes the changing monthly flow,flow rate and degrading factor,calculates dynamic assimilation ability by month,defines the concentration of different original fracture surfaces and computes different annul assimilation ability in reality and ideally,based on which varying trends of assimilation ability at different water stages would be analyzed.According to the analysis of existing data of Tao River between 2010 and 2013,pollution degradation coefficients of different months have been calculated in respective first ten-day,middle ten-day and last ten-day of a month.The back calculation of the results is compared with the water quality concentration in downstream of Tao River,by conducting rationality verification on the back calculation,thus defining the pollution degrading coefficients that fit the local area of Tao River better.Assuming the unchanged locations and number of drain outlets in the future,based on the back calculation of assimilative ability,through prediction of relevant parameters of assimilative ability in 2020 and supposing that pollution discharge exits will not change and increase in number,it is indicated that the assimilative ability of COD and ammonia nitrogen would be lower than the annual assimilative ability in 2015 due to the decreasing design water.Therefore,dynamic water quality management should be performed for Tao River by rationally utilizing the different assimilative abilities at different water periods,dynamically controlling the discharge of pollution and restricting the pollution discharge in normal water stage,while more strictly restricting the pollution discharge in dry year.According to the results of different schemes with regards to the dynamic pollution-receiving capabilities,the pollution-receiving capabilities of Tao River under different water seasons and with different degradation coefficients are researched.Amount of pollutants to be reduced is reasonably calculated.It is also planned that by 2020 and 2030 respectively,ecological cleaning,pollution cutting and diversion will be cooperatively carried out at the discharge exits with severe pollution during the process of planning,which would provide theoretical reference and scientific evidence for local water cleaning engineering and water quality management.