Zhejiang Daxue xuebao. Lixue ban (Jul 2024)
Characteristics of chemical compositions and sources of PM2.5 in winter at Lin′an(杭州市临安区冬季PM2.5化学组成特征和来源解析)
Abstract
In order to study the pollution characteristics and source contributions of PM2.5 at Lin'an, located in Hangzhou City, the PM2.5 component online monitoring was conducted from December 23, 2021, to February 28, 2022, and the sources apportionment of PM2.5 was conducted using positive matrix factorization (PMF). The mean concentration of PM2.5 was 53.91 μg·m-3 in winter, with NO3- and organic matter contributing the most, which accounted for 31.07% and 19.66%, respectively. NOR, SOR and SOC analysis showed that the secondary formation of PM2.5 was obvious in winter, which contributed largely to local PM2.5. Source apportionment showed that the air of Lin'an in winter was mainly affected by seven sources, namely secondary nitrate (52%), secondary sulfate (16%), vehicle exhaust (14%), coal (6%), dust (5%), industrial (5%) and biomass combustion (2%). During the episode, the contribution of secondary nitrate and vehicle exhaust increased, suggesting that local governments should control the impact of vehicle exhaust emissions on PM2.5 during pollution periods.(为研究杭州市临安区PM2.5的污染特征及来源，于2021年12月23日至2022年2月28日在线监测临安区的PM2.5，并运用正交矩阵因子分解法（PMF）进行来源解析。结果表明，观测期间临安区PM2.5平均质量浓度为53.91 μg·m-3，NO3-和有机物对PM2.5的贡献较大，分别占31.07%和19.66%。氮氧化率（NOR）、硫氧化率（SOR）和二次有机物（SOC）浓度的分析结果表明，临安区冬季PM2.5的二次转化较明显，对PM2.5有重要贡献。来源解析结果表明，临安区冬季PM2.5主要有七类来源，分别为二次硝酸盐（52%）、二次硫酸盐（16%）、机动车尾气（14%）、燃煤（6%）、扬尘（5%）、工业排放（5%）和生物质燃烧（2%）。在污染过程中，二次硝酸盐和机动车尾气的贡献有所上升，建议当地政府在污染期间控制机动车尾气排放，降低PM2.5浓度。)
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