title: [Composition of organic carbon/elemental carbon and water-soluble ions in rice straw burning].
abstract: Six types of rice straw were selected in China in this paper, the homemade biomass combustion devices were used to simulate the outdoor burning. The concentrations of organic carbon (OC), elemental carbon (C) and water-soluble ions in particular matter produced by the flaming and smoldering were analyzed using Thermal Optical Carbon Analyzer (Model 2001A) and Ion Chromatography(ISC 2000/ISC 3000). The results showed that the mean value of OC (EFoc) and EC (EFEC) emission factors were (6.37 +/- 1.86) g x kg(-1) and (1.07 +/- 0.30) g x kg(-1) under the flaming conditions, respectively, while under the smoldering conditions the two mean values were (37.63 +/- 6.26) g x kg(-1) and (4.98 x 1.42) g x kg(-1). PM, OC and EC emitted from the same kind of rice straw had similar change trends. The average values of OC/EC under flaming and smoldering were 5.96 and 7.80, and the value of OC/PM was almost unchanged along with the combustion state. Nevertheless, the values of EC/PM under flaming and smoldering were 0.06-0.08 and 0.08-0.11, respectively. The trend of combustion state could be determined using the ratio of EC/PM and the RZ of emitted OC and EC through those two types of combustion reached 0. 97, which was significantly correlated at the 0. 01 level. Among the anions, Cl- showed the highest concentration, the results indicated that the average value of of Cl- emission factor was (0.246 +/- 0.150) g x kg(-1) under flaming, while it was (0.301 +/- 0.274) g x kg(-1) under smoldering. However, A big difference between flaming and smoldering was found in the average value of K+ emission factor, where (0.118 +/- 0.051) g x kg(-1) of the former was significantly higher than the latter (0.053 +/- 0.031) g x kg(-1). When it came to Na, the result of smoldering was significantly higher than that of flaming. The correlation between water-soluble ions in flaming was more significant than smoldering. Rice straw burning could be distinguished from fossil fuels and some other biomass burning by the OC/EC ratio, and it could also be distinguished from sort of trees burning by the ratio of K+ /Na+, Cl-/Na+ in water-soluble ions.
authors.forename: Lei
authors.initials: L
authors.lastname: Hong
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Meng
authors.initials: M
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Jiu-hai
authors.initials: JH
authors.lastname: Li
authors.forename: Hui-yu
authors.initials: HY
authors.lastname: Chen
authors.forename: Ke
authors.initials: K
authors.lastname: Huang
authors.forename: Wei-zong
authors.initials: WZ
authors.lastname: Yang
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D018533:Biomass; D002244:Carbon / Q000737:chemistry*; D002681:China; D007477:Ions; D012275:Oryza; D052638:Particulate Matter / Q000032:analysis*; D014867:Water
chemical_list: D000393:Air Pollutants; D007477:Ions; D052638:Particulate Matter; D014867:Water; D002244:Carbon