Research On Dynamic Water Environmental Capacity Of Jiamusi Section Of Songhua River And Its Allocation Scheme

Providing institutional guarantees for the ecological protection red lines,the environmental quality baseline,and the resource utilization ceiling are important measures of environmental management in China at present,and the environmental quality baseline needs to reasonably distribute the total amount of pollution based on definite environmental carrying capacity.Therefore,the research on environmental carrying capacity of surface water is not only a requirement of environmental management,but also a hot issue of environmental science research.The Jiamusi section locates the Songhua River downstream,it not only crosses the Jiamusi city,but also flows into the Heilong River which is the boundary river between China and Russia.Heilong River is the most important international boundary of China,its water quality security is of great significance to safeguarding national interests,China-Russia relations,and economic development in border areas.Therefore,Jiamusi section of the Songhua River will be taken as the research object to study the environmental carrying capacity.The research results can not only provide scientific basis for the protection of the water environment quality and the rational utilization of the environmental capacity value of the Songhua River basin,but also provide valuable basic research for the management of the Songhua River basin.This paper has conducted a detailed investigation of the pollution sources in the Jiamusi section of the Songhua River Basin.The analysis of the pollution source with equivalent pollution load method shows that: 4 companies in Jiamusi directly discharged sewage into the river,the annual emission of COD is 167.5t,and the annual emission of ammonia nitrogen is 13.7t.There are 5 sewage treatment plants in the basin,except for Tongjiang Jieyuan Sewage Treatment Plant,all of them are in compliance with level I A standards.The annual load of point source COD is3168.3t,and the annual load of ammonia nitrogen is 407.1t.The annual Farmland runoff COD and ammonia nitrogen emissions are 154434 t and 30887 t respectively.The annual emissions of COD and ammonia nitrogen from livestock and poultry farming are 37523 t and 7505 t respectively.The annual emission of COD from rural domestic sources is 29688 t,and the annual emissions of ammonia nitrogen is 2787 t.The evaluation results of the current environmental quality of the river section using the standard index method show that: in general,the water quality of the river is good,it can meet the standard of Class III in "Surface Water Environmental Quality Standard" GB3838-2002.Two dimensional water quality model was used to calculate water environmental capacity,the COD environmental capacity of Jiangnantun-Tongjiang section is 82084t/a,and the ammonia nitrogen environmental capacity is 15922t/a,this section has the largest water environment capacity.The COD environmental capacity of Jiamusi-Jiangnantun section is 12372t/a,and the ammonia nitrogen environmental capacity is 3945t/a,this section has the smallest water environment capacity.Summer is significantly higher than other months,the maximum occurs in the high flow period,and the minimum occurs in the low flow period.Based on environmental capacity,establishing a set of index of capacity-total allocation,establishing system of distribution,taking into account factors such as policy,the cost of pollution reduction,and number of jobs provided,checking the consistency of the judgment matrix,the result will be more reasonable and feasible.Taking into account the main influencing factors,allocate the allocatable environmental capacity to industry,agriculture,and domestic pollution sources.Industrial sources allocate 16067 tons of COD environmental capacity and 2931 tons of ammonia nitrogen environmental capacity.Agricultural sources allocate106181 tons of COD environmental capacity and 20527 tons of ammonia nitrogen environmental capacity.Domestic pollution sources allocate 28377 tons of COD environmental capacity and 4362 tons of ammonia nitrogen environmental capacity.The industry and Domestic pollution sources are further allocated,industry is subdivided into enterprises,and domestic pollution sources are subdivided into sewage treatment plants and rural sources,the final allocation result of environmental capacity is obtained,and make recommendations based on the result.