摘要
为阐明气溶胶pH的关键影响因素及其污染源贡献,基于2023年西安市城郊PM_(2.5)样品水溶性离子和元素分析,结合ISORROPIAⅡ热力学平衡模型、正定矩阵因子分解模型与多元线性回归分析,系统评估了西安市城郊气溶胶pH水平及时空变化特征,分析了PM_(2.5)化学组分和气象参数对pH的影响,量化了不同污染来源贡献对气溶胶pH的影响。研究结果表明:西安市城郊PM_(2.5)整体呈弱酸性,城区和郊区气溶胶pH分别为5.1±1.7、5.2±1.7,受区域和季节影响显著,PM_(2.5)中二次无机离子对pH具有显著贡献;影响pH变化的关键驱动因子是TNO_(3)、SO_(4)^(2-)、TNH_(3)和Ca^(2+),且pH变化量对SO_(4)^(2-)比TNO_(3)更为敏感。多元线性回归分析显示:生物质燃烧和二次硝酸盐在城郊均表现出显著酸化作用,且生物质燃烧源在城区影响更强,二次硝酸盐在郊区影响更强;交通排放源在城区缓解了气溶胶酸性的增强,这可能与NH_(3)的中和作用有关,而二次硫酸盐在郊区对酸性的强化作用可能是由于其生成对污染传输和多相氧化作用更为敏感。
To elucidate the key factors influencing aerosol pH and pollution source contributions,levels and spatiotemporal variations of aerosol pH in urban and suburban areas of Xi’an were systematically evaluated,effects of chemical particles comprising PM_(2.5) and meteorological parameters on pH were analyzed,and contributions of different pollution sources to the aerosol pH was quantified in this study based on water-soluble ion and element analysis of PM_(2.5) samples collected from urban and suburban areas of Xi’an in 2023,in combination with the ISORROPIAⅡthermodynamic equilibrium model,the positive matrix factorization model,and multiple linear regression analysis.The research results show that PM_(2.5) in the urban and suburban areas of Xi’an was generally weak acidic:The aerosol pH in urban and suburban areas was 5.1±1.7 and 5.2±1.7 respectively,subject to significant variations in different areas and seasons;a notable contribution of secondary inorganic ions in PM 2.5 to the aerosol acidity was observed;the key driving factors affecting pH were TNO_(3),SO_(4)^(2-),TNH_(3),and Ca^(2+),withΔpH being more sensitive to SO_(4)^(2-) than to TNO_(3).Multiple linear regression analysis indicated that biomass burning and secondary nitrate had significant acidifying effects in both urban and suburban areas.Biomass burning had a stronger effect in urban areas,while secondary nitrate had a more pronounced effect in suburban areas.Traffic emissions appeared to have mitigated aerosol acidity in urban areas,possibly due to the neutralizing effect of NH 3.The enhanced acidifying effect of secondary sulfate in suburban areas might be attributed to its higher sensitivity to pollution transport and multiphase oxidation processes.
作者
王亚楠
杨舒淇
吴佳霖
杨旭
杨凡
王昭
何炽
刘佛傍
WANG Yanan;YANG Shuqi;WU Jialin;YANG Xu;YANG Fan;WANG Zhao;HE Chi;LIU Fobang(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Shaanxi Provincial Land Engineering Construction Group Co.,Ltd.,Xi’an 710024,China)
出处
《西安交通大学学报》
北大核心
2025年第12期58-68,共11页
Journal of Xi'an Jiaotong University
基金
陕西省科学技术厅秦创原引用高层次创新企业人才项目(QCYRCXM-2022-363)。
