Singh Gyanesh Kumar, Qadri Adnan Mateen, Paul Debajyoti, Gupta Tarun, Mukherjee Sauryadeep, Chatterjee Abhijit
Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
Department of Earth Sciences, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
Chemosphere. 2023 Jun;326:138422. doi: 10.1016/j.chemosphere.2023.138422. Epub 2023 Mar 14.
This study reports the chemical characterization of the carbonaceous component of PM (particulate matter with aerodynamic diameter ≤2.5 μm) collected over a year-long campaign from a regional site in Shyamnagar, West Bengal, in the Indo-Gangetic Plains (IGP), India. The carbonaceous fractions (elemental and organic carbon), mass concentrations, and stable carbon isotopic composition (δC value) of aerosols were measured and utilized to characterize the sources and understand the atmospheric processing of aerosols. Cluster analysis, Potential Source Contribution Function (PSCF) modeling, and fire count data were analyzed to decipher the pattern of air masses, source contributions, and extent of burning activities. The PM mass concentrations were significantly higher during winter (168.3 ± 56.3 μg m) and post-monsoon (109.8 ± 59.1 μg m) compared to the monsoon (29.8 ± 10.7 μg m) and pre-monsoon (55.1 ± 23.0 μg m). Organic carbon (OC), elemental carbon (EC), and total carbon (TC) concentrations were also several factors higher during winter and post-monsoon compared to monsoon and pre-monsoon. The winter and post-monsoon experienced the impact of air masses from upwind IGP. On the other hand, long-range transported air masses from the South-West direction dominated during monsoon and pre-monsoon, which are also relatively cleaner periods. The average δC during post-monsoon and winter was ∼1‰ higher compared to monsoon and pre-monsoon. The vehicular exhaust and biomass/biofuel burning contributed dominantly in winter and post-monsoon. In comparison, lower δC in pre-monsoon and monsoon might be attributed to the dominance of biomass/biofuel combustion. Photochemical-induced aging of the anthropogenic aerosols resulted in a higher δC of TC in winter and post-monsoon, whereas the mixing of different local sources in pre-monsoon and monsoon resulted in lower δC values. These findings benefit policymakers in strategizing proper and effective management of biomass/biofuel burning in the IGP to minimize air pollution.
本研究报告了在印度恒河平原（IGP）西孟加拉邦沙姆纳加尔的一个区域站点进行的为期一年的采样活动中收集的细颗粒物（PM，空气动力学直径≤2.5μm的颗粒物）中碳质成分的化学特征。测量了气溶胶的碳质组分（元素碳和有机碳）、质量浓度和稳定碳同位素组成（δC值），并用于表征气溶胶的来源和了解其大气过程。分析了聚类分析、潜在源贡献函数（PSCF）模型和火灾计数数据，以解读气团模式、源贡献和燃烧活动程度。与季风期（29.8±10.7μg/m）和季风前期（55.1±23.0μg/m）相比，冬季（168.3±56.3μg/m）和季风后期（109.8±59.1μg/m）的PM质量浓度显著更高。与季风期和季风前期相比，冬季和季风后期的有机碳（OC）、元素碳（EC）和总碳（TC）浓度也高出几个数量级。冬季和季风后期受到来自IGP上游气团的影响。另一方面，在季风期和季风前期，来自西南方向的远距离传输气团占主导，这也是相对清洁的时期。与季风期和季风前期相比，季风后期和冬季的平均δC高出约1‰。车辆尾气排放和生物质/生物燃料燃烧在冬季和季风后期占主导。相比之下，季风前期和季风期较低的δC可能归因于生物质/生物燃料燃烧占主导。人为气溶胶的光化学老化导致冬季和季风后期TC的δC较高，而季风前期和季风期不同本地源的混合导致δC值较低。这些发现有助于政策制定者制定IGP生物质/生物燃料燃烧的适当有效管理策略，以尽量减少空气污染。
