Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Evolution of biomass burning smoke particles in the dark
Abstract The evolution in the dark of physiochemical properties and chemical composition of smoke particles emitted from wheat straw burning, as well as the effect of relative humidity (RH) on these properties, was investigated in an aerosol chamber. The smoke particles are composed primarily of carbonaceous materials and a considerable amount of inorganic salts (∼25 wt.%). During aging, the fraction of inorganic salts in smoke PM1.0 increases, mainly due to the formation of more sulfate and nitrate at the expense of chloride; this heterogeneous conversion is facilitated at high RH. The hygroscopicity parameter κH of fresh smoke particles is 0.27 and this is estimated to decrease by 0.01 after 4 h dark aging. Both aging and high RH lead to increases of particle size and density. The effective densities of smoke PM2.5 and PM1.0 deduced from concurrent mass and volume concentration measurements gradually increase from about 1.18 to 1.44 g/m3 within 4 h aging at 45%–55% RH, in line with the results obtained both from size-resolved particle density analysis using an aerosol particle mass analyzer (APM) and from estimation using composition-weighted bulk densities. The density of smoke particle is size-, RH-, and aging extent-dependent; the size effect becomes less pronounced with aging.
Highlights Aerosol chamber simulation of agricultural residue burning in the dark. Hygroscopicity and effective density measurement using TDMA-APM system. RH effect on smoke particle chemical and effective density evolution. Density growth with the chemical evolution and morphology changes of smoke particle.
Evolution of biomass burning smoke particles in the dark
Abstract The evolution in the dark of physiochemical properties and chemical composition of smoke particles emitted from wheat straw burning, as well as the effect of relative humidity (RH) on these properties, was investigated in an aerosol chamber. The smoke particles are composed primarily of carbonaceous materials and a considerable amount of inorganic salts (∼25 wt.%). During aging, the fraction of inorganic salts in smoke PM1.0 increases, mainly due to the formation of more sulfate and nitrate at the expense of chloride; this heterogeneous conversion is facilitated at high RH. The hygroscopicity parameter κH of fresh smoke particles is 0.27 and this is estimated to decrease by 0.01 after 4 h dark aging. Both aging and high RH lead to increases of particle size and density. The effective densities of smoke PM2.5 and PM1.0 deduced from concurrent mass and volume concentration measurements gradually increase from about 1.18 to 1.44 g/m3 within 4 h aging at 45%–55% RH, in line with the results obtained both from size-resolved particle density analysis using an aerosol particle mass analyzer (APM) and from estimation using composition-weighted bulk densities. The density of smoke particle is size-, RH-, and aging extent-dependent; the size effect becomes less pronounced with aging.
Highlights Aerosol chamber simulation of agricultural residue burning in the dark. Hygroscopicity and effective density measurement using TDMA-APM system. RH effect on smoke particle chemical and effective density evolution. Density growth with the chemical evolution and morphology changes of smoke particle.
Evolution of biomass burning smoke particles in the dark
Li, Chunlin (Autor:in) / Ma, Zhen (Autor:in) / Chen, Jianmin (Autor:in) / Wang, Xinming (Autor:in) / Ye, Xingnan (Autor:in) / Wang, Lin (Autor:in) / Yang, Xin (Autor:in) / Kan, Haidong (Autor:in) / Donaldson, D.J. (Autor:in) / Mellouki, Abdelwahid (Autor:in)
Atmospheric Environment ; 120 ; 244-252
01.09.2015
9 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch