The Calculation And Research Of Water Environmental Capacity For Artificial Controlled Semi-close River

The calculation of water environmental capacity is the base of total quantity control. There are always gates on small rivers, so the small rivers are semi-close. The data for these rivers are lacked and the calculation of water environmental capacity is difficult. The thesis research the calculation method of water environmental capacity for artificial controlled semi-close river taking Laofuhe River as an example.According to the character of semi-close river, the degradation coefficient of COD and NH₃-N for different sections was measured through indoor experiments. Comparing with using single degradation coefficient, the result is exacter.At present, the research of environmental capacity for Cl^- is weak. The thesis research the release and absorption function of sediment to Cl^- by simulative experiment and found the relation between the amount of Cl^- released and absorbed by sediment and the time. Then the environmental capacity for Cl^- is calculated by appropriate model. This research has practical property for the total quantity control of Cl^-.The water environmental capacity of artificial controlled semi-close river is fluctuant. The daily perfect environmental capacity of multiple situations is calculated by three models and the integrated perfect environmental capacity of the whole year is calculated by temporal and spatial adding. The environmental capacity level calculated by this method is matching with the scale of the water body and is propitious to make the best use of environmental capacity.In order to reflect the pollutant discharge of industrial pollution source more factually, the pollutant discharge is divided into two instances: pollutants completely treatment discharge and pollutants non-completely treatment discharge. Calculating the residual environmental capacity or the amount of pollutant to cut on this base is near to the fact.The thesis provides scientific integrated case study for the calculation of water environmental capacity for the artificial controlled semi-close river and has property of pertinence and practically.