A Laboratory Study On Emission Characteristics Of Gaseous And Particulate Pollutants Emitted From Agricultural Crop Residue Burning In China

Biomass burning is an important source of gaseous and particulate pollutants in theatmosphere and has a significant impact on global atmospheric chemistry, global climateand global ecosystem change. In China, Agricultural crop residue is abundant and asignificant type of biomass burning. In order to estimate regional environmental impact andclimate effect, the emission characteristics of aerosol emitted from the burning ofagricultural crop residues should be investigated. Based on the above ideas, the gaseous andparticulate emission characteristics, the size distribution and growth characteristics ofemitted particles, the PAHs and APAHs emission characteristics from the burning of rice,wheat and corn straws, which are three major agricultural crop residues in China, are alsoinvestigated, using a self-built burning stove and an aerosol chamber equipped with a set ofanalytical instruments.There are three main contents in this work, as following:The first part investigates the emission factors, emission ratios and combustionefficiency of gaseous pollutants emitted from the burning of three main agricultural cropresidues-rice, wheat and corn straws- in China. The emission inventories and emissionallocations of gaseous pollutants (CO, CO₂ and NO_x) from rice, wheat and corn strawburnings in China for the year 2004 were also estimated.The second part is to study the size distribution characteristics, growth characteristicsof particles emitted from the burning of three main agricultural crop residues-rice, wheatand corn straws- in China. The size distributions of emitted particles are well characterizedby unimodal lognormal functions, with a remarkable feature of accumulation mode. Thegrowth rate is also determined during smoke age. Moreover, the number emission factors,the mass emission factors, the emission inventories and emission allocations of fresh smokeparticles from rice, wheat and corn straw burnings in China for the year 2004 were alsoestimated.The final part is to investigate the emission factors of PAHs and APAHs in the gas andparticle from the burning of three agricultural crop residues in detail. And the emissioninventories and emission allocations of PAHs and APAHs from rice, wheat and corn strawburnings in China for the year 2004 were also estimated.The emission characteristics of gaseous pollutants, fresh smoke particles and PAHs and APAHs emitted from agricultural crop residue burning are systematically investigated, andthe size distributions and growth characteristics of fresh smoke particles are also estimatedin the above three parts. This work could further reveal regional environmental impact andclimate effect caused by the burning of biomass burning, and provides the basic data for theregional climate modeling and climate change simulation. This study also provides thescientific basis for policy maker and our country's climate and environment diplomacy.