The Emission Permit System Design Of Livestockand Poultry Breeding Based On Water Qualityobjectives In Zhexi Reservoir Basin

Emission Permit is an environmental management means,which is considered an effective way to control pollutant emission and regulate pollutant emission at fixed point-sources.In recent years,Emission Permit System has been widely applied in the US,EU and many other countries etc.Therefore,it is taken into consideration that our country will to greatly promote researches of Emission Permit System by transforming pollutant concentration and quantity control into core environment management system,which will be of great significance to formation and implementation of Pollutant Emission Permit System.This paper is aimed at proposing feasible routes that are applicable to our country's emission system through analyzing and comparing foreign effective emission permit systems and regulatory methods in general.This research is conducted on total nitrogen as water control object based on basin and large-scale livestock and poultry breeding,which is divided into control unit and control area on the basis of nature geographical index,water environment and water ecological index etc.On top of that,by calculating the water environmental capacity of basin,it mainly analyzes pollutant circumstances on basin.Meanwhile,it confirms pollution load of livestock and poultry breeding and its contribution rate,as well as the responding relation among environmental margin of different control units and large-scale poultry breeding load.As a result,it is also indicated that some feasible proposals and measures are raised on emission permit and pollutant regulatory,regarding large-scale livestock and poultry breeding around Zhexi reservoir basin.According to the principles of pollutant emission permit system,this paper combines national environmental regulatory route of "From top to bottom" and "from bottom to top".Based on the responding relation among environmental capacity,environmental quality and pollutant emission load,it raises design proposals for pollutant emission permit of basin.Concerning basin with adequate environment capacity,it applies emission permit design proposals based on industry pollutant emission limits.On the other hand,on the premise of present pollutant treatment technology,it confirms pollutant emission limits of different enterprise pollutant emission.Regarding basin with relatively large pollutant load where water environment capacity exceeds water environment target function requirements,it applies emission permit design proposals based on environmental quality and cap total capacity target,which is to allocate environment capacity on the basis of environmental capacity and contribution rate of pollutant emission at different pollutant sources.In addition,according to maximum allowable water environmental capacity and different production modes,technology level and treatment technology etc,it confirms pollutant emission limits and pollutant emission of different point-sources.Based on law of conservation of mass and river hydrodynamics theory,this paper focus ones building up water quality model.According to created conditions,it generalizes water area and selects hydrological parameter,background concentration and water quality target and further calculate different regulated water environmental capacity.Through calculating water quality model,TN water environmental capacity in Zhexi reservoir basin is up to 4048.4t/a,with Meiyuan of 1611.2t/a,Youxi of 339.6t/a?Pingkou of 636.5t/a,Yanxi 881.2t/a,Daba of 328.0t/a,and Dongping of 251.7t/a.Meanwhile,based on research statistics of pollutant sources,it applies pollutant generation and discharge coefficients method to verify pollutant inlet coefficient of livestock and poultry breeding and TN emission within each pig's growth.On the basis of control units division,it respectively calculates livestock and poultry breeding pollution and verifies TN inlet quantity of different watershed control units in Zhexi reservoir.At last,it comes to the maximum environmental capacity of large-scale livestock and poultry breeding in Zhexi reservoir basin.Through environmental capacity analysis of Zhaoxi reservoir basin,it put forwards some emission permit design proposals of different control units.In control units of Meiyuan,Pingkou and Yanxi,environmental capacity of large-scale livestock and poultry breeding is relatively adequate and employs emission permit design proposals based on industry pollutant emission limits.As for Youxi control unit,it verifies pollutant emission limits by livestock and poultry breeding pollutant emission standards,which,however,fails to meet environmental quality requirements.Furthermore,it applies emission permit design proposals of environment quality and total capacity target,which is aimed at regulating different enterprises on pollutant emission.Concerning Daba and Dongping control unit,since there are a large number of retail inventors of livestock and poultry breeding,TN pollutant emission has far exceeded water environmental capacity of watershed livestock and poultry breeding.Therefore,in order to improve watershed water environmental quality,it puts forward a pollution treatment proposal based on two aspects,which are to reduce the number of retail inventors in livestock and poultry breeding and increase the ratio of large-scale livestock and poultry breeding in basin.