Centre for the Study of Regional Development, Jawaharlal Nehru University, New Delhi, 110067, India.
School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
Environ Monit Assess. 2018 Oct 22;190(11):663. doi: 10.1007/s10661-018-6999-2.
Open-field crop residue burning is one of the important sources of atmospheric pollution in north-west India during the harvesting period. In this work, we studied NO and SO concentrations and physical and chemical properties of aerosols from open-field combustion of rice and wheat residue. NO and SO were analysed using UV-spectrophotometer and ion chromatography (IC) respectively. The aerosol particles were analysed by scan electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) for their physical dimension (size distribution) and elemental composition, and by IC for their ionic content. The measured concentrations of gases during burning showed rice straw burning spews more NO and SO than wheat straw burning. The calculated size of the particles ranged from 0.26 to 151.09 μm with high standard deviation. The median diameter of 1.64 μm (± 6.9) represented the central tendency of the particles emitted due to this combustion process. Comparative content analysis revealed that rice-borne particles are richer in Na, K, Al, Si and Zn, whereas, wheat-borne particles are more abundant in C, Mg, Fe, P and Cl. The results from IC and SEM-EDX evidenced the presence of fluoride, sulphate, carbonate, chloride, oxides and silicate compounds in particles. The emission of greenhouse gases (GHGs) and aerosols with this particle chemistry increases the atmospheric opacity through the absorption and scattering of incoming radiation at a significant amount in the UV-IR range causing high aerosol optical depth (AOD).
田间作物残茬燃烧是印度西北部收获期大气污染的重要来源之一。在这项工作中，我们研究了田间燃烧水稻和小麦秸秆产生的 NO 和 SO 浓度以及气溶胶的物理和化学性质。NO 和 SO 分别用紫外分光光度计和离子色谱（IC）分析。利用扫描电子显微镜结合能量色散 X 射线光谱（SEM-EDX）分析气溶胶粒子的物理尺寸（粒径分布）和元素组成，并用 IC 分析其离子含量。燃烧过程中测量的气体浓度表明，稻草燃烧比麦草燃烧排放更多的 NO 和 SO。计算得到的粒子尺寸范围为 0.26 至 151.09μm，标准偏差很高。粒径中位数为 1.64μm（±6.9），代表了由于这种燃烧过程而产生的粒子的中心趋势。比较含量分析表明，稻秆颗粒中含有更多的 Na、K、Al、Si 和 Zn，而小麦秆颗粒中含有更多的 C、Mg、Fe、P 和 Cl。IC 和 SEM-EDX 的结果表明，颗粒中存在氟化物、硫酸盐、碳酸盐、氯化物、氧化物和硅酸盐化合物。这些粒子化学物质的温室气体（GHGs）和气溶胶的排放会通过在 UV-IR 范围内吸收和散射入射辐射，导致大气不透明度显著增加，从而使气溶胶光学厚度（AOD）增加。
