Study On Pollutant Emission Inventory And Transmission Of Straw Open Burning In Heilongjiang Province

As one of the most important commodity grain bases in China,Heilongjiang Province has increased its grain output year after year.The continuous growth of grain output will inevitably produce a large amount of straw resources,and nearly 30% can only be treated by open burning,and straw burning will produce a large amount of particulate matter.In the past five years,the essence of the hazy weather that frequently erupted in spring and autumn in Heilongjiang Province is particulate matter pollution.Therefore,Heilongjiang Province urgently needs to establish a more detailed,reliable and localized high-resolution straw open-air incineration pollutant discharge list.This study uses 2017 as the base year,first adopts the “top-down method” and“bottom-up method” recommended by the “Guide” to estimate the 2017 open straw incineration discharge list of Heilongjiang Province based on the prefecture and county.The uncertainty and reliability of the list are analyzed,and the list is distributed in time and space.The 3km×3km resolution of the straw open burning incineration gridded emission inventory is obtained.Based on the backward trajectory model and its analysis method,the straw open-air analysis is qualitatively and quantitatively analyzed.The impact of incineration on regional air quality in Heilongjiang Province was analyzed.The Boston matrix was used to analyze the pressure and potential of straw open burning and emission reduction,and the direction of future straw management in Heilongjiang Province was proposed.Based on remote sensing monitoring of the area of straw incineration fires and accurate crop yields at the county level,it is estimated that the total open burning of straw in the counties and districts of Heilongjiang Province in 2017 will be: CO₂ 3517.55 ten thousand t,CO 14.62 ten thousand t,CH₄ 8.69 ten thousand t,NMVOCs 20.14 ten thousand t,NH₃ 1.73 ten thousand t,EC 1.14 ten thousand t,BC 1.06 ten thousand t,OC 9.19 ten thousand t,SO₂ 1.28 ten thousand t,NO_x 7.28 ten thousand t,PM_2.5 38.90 ten thousand t.The “bottom-up method” results are higher than the “top-down method”: CO₂ is 18.98% higher,CO is 33.65% higher,CH₄ is 2% higher,NMVOCsis 5.45%higher,NH₃ is 16.61% higher,EC is 26.26% higher,and BC is 12.51.% higher,OC is21.69% higher,SO₂ is 19.31% higher,NO_x is lower at 4.54%,and PM_2.5is higher at41.47%.Discharge of PM_2.5 in straw open burning in Heilongjiang Province in 2017:April>Octo>March>November>May>September>June>July>August,The daliy high emissions of typical straw burning month Mainly distributed in late March,early andmid-April,mid-late October and early November.The spatial distribution characteristics are: Harbin > Suihua > Qiqihar > Jiamusi > Daqing > Heihe > Mudanjiang > Jixi >Shuangyashan > Qitaihe > Hegang > Yichun > Daxinganling.Analysis of the air pollution process caused by straw burning in Harbin in October2017,found that the air mass from the southwest has the greatest impact on the air quality of Harbin,Suihua,Daqing,Jilin,Inner Mongolia,Liaoning and the local Bayan,Shuangcheng,Binxian and other regions.It is a potential source area of Harbin.Based on the results of PSR evaluation of straw open burning in Heilongjiang Province in Boston matrix,the formulation of regional straw burning control policy should be carried out according to the economic development level of each region.The key control areas are Harbin,Suihua,Qiqihar,Jiamusi and Daqing.The key control period is In March,April,November and November,guided combustion can be carried out according to meteorological conditions and topographical features,but at the same time,the comprehensive utilization intensity of straw in the province should be increased.