Study On The Methodology Of Emission Allocation And Integrated Assessment Of Air Pollutant Permit

At present,the situation of prevention and control of air pollution in China is still very serious.In 2018,among 338 cities in China,only 121 cities met the air quality standard?i.e.the concentration of six pollutants met the standard,accounting for 36%?,190 cities still exceeded the air quality standard of PM_2.5?the excess rate is 56%?,and there is still a long way to go to prevent and control the PM_2.5 pollution.According to China Environmental Statistics Bulletin,the industrial department of the fixed point source were discharged 83.73%SO₂,63.77%NO_x and 80.14%smoke dust emissions in 2015.Now,China mainly through emission permit system to manage the emissions of fixed point source scientifically and reasonably.The pollutant concentration is effected to emission permit system by allocating the pollutant emission permit to enterprises and supervising the actual emission of pollutant,and then related to the improvement of ecological environment quality.Since the reform in 2016,emission permit system cannot be linked with the improvement of the ecological environment quality,and cannot quantitatively estimate the real value of the current allocation method of emission permit in terms of effectiveness assessment,efficiency assessment,and equity assessment,and cannot support the further reform of emission permit system and the reform of total emission control system.Based on the above background and management needs,this study summarizes the research progress and shortcomings in the field of allocation and assessment,and then determines the scientific question,that is,how to construct the allocation and integrated assessment system of air pollutant emission at point source scale.Firstly,aiming at the allocation problem in scientific question,this study creatively constructs air pollutant emission allocation model at enterprises?discharge outlets?scale based on Emission Standard Method?M1?,Emission Standard+Urban Transmission Method?M2?,Environmental Capacity Method?M3?.Based on the current situation of air pollutant emission of enterprises?discharge outlets?in Urban Emission Inventory?M0?,combined with the current practice of emission permit system and allocation method,the transmission matrix and the environmental capacity of urban air pollutant,and combined with"technical specification for application and issuance of emission permit"of the industry of the industrial boiler,cement,glass,coking,steel,this study constructs the allocation model of air pollutant emission permit at enterprises?discharge outlets?scale based on M1,M2 and M3,respectively.Secondly,in view of the assessment problem of scientific question,this study innovatively constructs an integrated assessment system of allocation results,including Effectiveness Assessment?Air Quality Assessment,AQA?,Efficiency Assessment?Cost-benefit Assessment,CA?,Equity Assessment?EA?,and 3E Integrated Assessment.In this part,First of all,based on regional emission inventory as the bottom inventory,the point source emission inventories based on M0 and M1,M2 and M3 are added respectively.Taking Beijing and its surrounding cities as the core simulation area,this study constructs a three-layer nested grid WRF-CMAQ to assess the allocation results.The next,based on the simulated concentration difference of PM_2.5 between M1,M2,M3 and M0,and based on the emission difference of SO₂,NO_x,primary PM_2.5between M1,M2,M3 and M0,combined with the health endpoint,exposed population,response coefficient and monetization parameter,this study constructs the health benefit assessment model based on environmental risk assessment and monetization assessment,and the cost assessment model of pollutant emission reduction to carry out the efficiency assessment of allocation results.And then,based on the SO₂,NO_x,primary PM_2.5 emissions of M0,M1,M2 and M3,add the emissions of other industries in M0 except for the 5 industries respectively,combined with the industrial GDP,industrial profits,industrial added value,industrial employment population of Beijing and its surrounding cities,this study constructs the equity assessment model based on Environmental Gini Coefficient?EGC?and Green Contribution Coefficient?GCC?to carry out the equity assessment of allocation results.Finally,based on the above assessment results of effectiveness,efficiency and equity,according to corresponding score of pollutant concentration,net benefit,EGC and GCC,and the weight coefficient by the experts,this study innovatively constructs a single assessment model based on AQA,CA and EA,and an integrated assessment model based on 3E integrated assessment to carry out the integrated assessment of allocation results.There are five main results in this study:?a?in terms of allowable emission allocation results,the allowable emissions of SO₂ of M1,M2,M3 in Beijing and its surrounding cities are 7.90,4.92 and 22.27 ten thousand t/a,respectively.The allowable emissions of NO_x are 21.91,13.56 and 15.34 ten thousand t/a,respectively.The allowable emissions of primary PM_2.5 are 3.54,2.22 and 7.82 ten thousand t/a,respectively.?b?In terms of effectiveness assessment results,the simulated concentrations of SO₂ of M1,M2 and M3 in Beijing and its surrounding cities are 30.53,29.83 and 34.902)/8)³,respectively.The simulated concentrations of NO₂ are 49.98,49.43 and 49.502)/8)³,respectively.The simulated concentrations of PM_2.5 are 62.15,61.44 and 63.912)/8)³,respectively.?c?In terms of efficiency assessment results,the health benefits of M1,M2 and M3 in Beijing and its surrounding cities are 19.605,22.041 and 10.224 billion yuan,respectively.The costs are 0.485,0.817 and 0.509 billion yuan,respectively.The net benefits are 19.120,21.223 and 9.715 billion yuan,respectively.?d?In terms of equity assessment results,based on economic and social data and SO₂ emission,the EGC of M1,M2 and M3 are 0.4530,0.4573 and 0.4783,respectively.Based on economic and social data and NO_x emission,the EGC of M1,M2 and M3 are0.4598,0.4696 and 0.4642,respectively.Based on economic and social data and primary PM_2.5 emission,the EGC of M1,M2 and M3 are 0.3861,0.4319 and 0.4479,respectively.Among the GCC of M1,M2 and M3 based on the economic and social data and pollutants emission,those in Beijing are higher than 1.5,those in Tangshan are lower than 0.5,and those in other cities are higher or lower than 1.0.?e?In terms of 3E integrated assessment results,the 3E integrated assessment scores of M1,M2 and M3 were 56.91,57.94 and 55.74,respectively.The scores of AQA based on M1,M2 and M3 are 47.54,47.97 and 45.97,respectively.The scores of CA based on M1,M2 and M3 were 76.66,76.91 and 68.68,respectively.The scores of EA based on M1,M2 and M3 were 49.66,52.27 and 55.82,respectively.There are four main conclusions in this study:?1?the transmission matrix and environmental capacity of urban air pollutant can be drawn into the allocation method at the point source scale,so that the allocation method can be linked with the improvement of ecological environment quality.?2?The effectiveness assessment,efficiency assessment and equity assessment of allocation results can be well integrated into the 3E integrated assessment,so that multiple allocation methods can be compared in single aspect and integrated aspect.?3?The integrated assessment system including effectiveness assessment,efficiency assessment,equity assessment and 3E integrated assessment can quantitatively assess the performance of allocation method in different aspects such as effectiveness?environmental quality?,efficiency?cost-benefit?,and equity,integrated.?4?The comparison of scores of 3E integrated assessment?M2>M1>M3?based on different allocation methods shows that under the current air pollutant emissions,the emission standard+urban transmission method>the emission standard method>the environmental capacity method.Among them,in the comparison of scores of AQA based on different allocation methods,M2>M1>M3.In the comparison of scores of CA based on different allocation methods,M2>M1>M3.In the comparison of scores of EA based on different allocation methods,M3>M2>M1.This study shows that the system of allocation method and integrated assessment promotes the development of the allocation method and assessment technology of emission permit in China,and provides research ideas,technologies and methods in the fields of emission permit,total emission control.In addition,this study provides technical support for the scientific and reasonable allocation of point source of emission permit and total emission control in China,and supports the further reform of emission permit system and the reform of total emission control system.