title: Characteristics of carbonaceous aerosols: Impact of biomass burning and secondary formation in summertime in a rural area of the North China Plain.
abstract: To determine the characteristics of carbonaceous aerosols in rural areas of the North China Plain, field measurements were conducted at Yucheng (YC) in the summers of 2013 and 2014. The concentrations of carbonaceous aerosols at YC exhibited clear diurnal variation, with higher concentrations in the early morning and at night and lower concentrations during the afternoon hours. The mass-balance method designed for particulate matter smaller than 2.5μm (PM2.5) was used to calculate the organic matter (OM)/organic carbon (OC) ratio. The value obtained, 2.07±0.05, was suggested as a reference to estimate organics in PM2.5 in rural areas of the North China Plain. Biomass burning was identified to be a significant source of carbonaceous aerosols; approximately half of the samples obtained at YC were affected by biomass burning during summer 2013. Case studies revealed that biomass burning accounted for up to 52.6% of the OC and 51.1% of the elemental carbon in PM2.5 samples. The organic coatings observed on sulphur-rich and potassium-rich particles indicated the formation of secondary organic aerosols (SOA) from the oxidation of precursor volatile organic compounds (VOCs) during the aging of smoke released from biomass burning. Based on the evolution of the VOCs, the contribution of VOCs oxidation to SOA concentration was 3.21 and 1.07μgm(-3)ppm(-1) CO under conditions of low nitrogen oxide (NOx) and high NOx, respectively. Aromatics (e.g. benzene, toluene, xylene and ethylbenzene) made the greatest contribution to SOA concentration (88.4% in low-NOx conditions and 80.6% in high-NOx conditions). The results of the study offer novel insights into the effects of biomass burning on the carbonaceous aerosols and SOA formation in polluted rural areas.
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Yao
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China; School of Environmental Science and Engineering, Shandong University, Jinan 250100, China. Electronic address: yanglingxiao@sdu.edu.cn.
authors.forename: Lingxiao
authors.initials: L
authors.lastname: Yang
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China; School of Environmental Science and Engineering, Shandong University, Jinan 250100, China; Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan Tyndall Centre, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Chen
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Likun
authors.initials: L
authors.lastname: Xue
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Li
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Sui
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wen
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Chi
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Junmei
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Caihong
authors.initials: C
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Environment Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhu
authors.affiliation: Environment Research Institute, Shandong University, Jinan 250100, China.
authors.forename: Wenxing
authors.initials: W
authors.lastname: Wang
keywords: Biomass burning; Carbonaceous aerosols; OM/OC ratio; SOA formation