| Biomass burning in domestic stoves is still a main energy source for heating and cooking in rural areas of northeast China.Emissions from biomass burning,including rice straw,soybean straw,and corn stalk burning play an important role in severe haze pollution,which has a significant impact on air quality,public health and climate change.To know the characteristics of emission from biomass domestic stoves,a fixed source particulate matter(PM)sampling system was built for a typical cold area stove testing.The stove joined to Kang and to a wall with flues for heating.We obtained the parameters of particle size distribution,emission factors and chemical composition,thus toestablish a source profile of biomas burning stoves.It will provide scentific data to support the analysis of the formation mechanism of haze,the source apportionment of PM,the design of air pollution control technologies,and emission reduction policies.In the research,three types of biomass were selected,including rice straw,soybean strawand corn stalk.Samples were collected by the dilution stack system.We got the emission characteristics of OC and EC in PM.The comparison showed that the OC/EC in this study was generally lower than that in other studies,the proportion of EC produced was higher,and the oxygen supply and ventilation conditions of the stove need to be improved.The EFT-PAHs based on field test of the stove was much higher than that of the smoke box,which indicated that the total emission based on the laboratory test results may be lower than real.The peak of EFPAHs value calculated according to the PAHs rings was same as that of other study in Harbin,which reflected the great impact of straw burning.And we found that Flu/(Flu+Pyr)and Icd P/(Icd P+Bghi P)could be used to preliminarily identify straw burning sources,while Ant/(Ant+Phe)and Ba P/(Ba P+Bghi P)values could further distinguish stove combustion from open burning.The element analysis showed that the content of Al and Ca in PM2.5/1.0 was more than 10 mg / g,and their sum accounted for more than 70% of the test components;The contents of Mg,Ti,Cr and Ni are more than 1.0 mg/g;and the contents of Zn,Mn,Pb,V,Cd,as and Ti were less than 1.0 mg/g;The contents of corn-mg,soybean-Cd,Tl,Pb and rice-As were significantly higher than those of other straws’ results.Water soluble ion(WSI)analysis shows that the sum of K? and Cl? accounts for more than 50% of WSI and were significantly correlated,which could be an ideal ion for source identification.Three indicative ions,rice-Na?,soybean-SO?2? and corn-Mg2?,could further identify different types of straw combustion.TC/OC/EC,Cl?/K?,Mg2?/Ca2?/NH??/NO?? were significantly correlated to PM.In addition,K? was also significantly related to OC or EC.K?/OC or K?/EC could also identify the emission sources of straw combustion in stoves.The maximum single peak distribution of the PM emitted from rice,soybean and corn straw combustion was in the range of 0.56-1.0 μ m,0.32-0.56 μ m and 1.0-1.8 μ m,respectively.The PM below 3.2 μm account for more than 80% of the total mass.The source profile showed that the proportion of carbon components,including EC and OM,was about 60%,even 72.78% in rice-PM2.5.By comparing the source profile and combining the Flu/(Flu+Pyr)and Ant/(Ant+Phe),we found that PAHs of PM in Harbin were siginificantly affected by the emission sources of stoves.The results showed that the peak for OC and EC were in the range of 0.18-0.56 μm,rice-As was in the range of 0.32-0.56 μm,and soybean-Cd was in the range of 0.32-0.56 μm.As a whole,Mg,Ti,Ni,Cr,V,Zn,Mn,Pb,OC and EC of the particles before 3.2 μm have peak content,with health risk.Therefore,the emission control of stover,including the improvement of stoves and the research and development of smoke and dust treatment technology for household stoves,needs to be strengthened urgently,and at this stage,personal protection for stoves user must be done well. |
