清洁能源政策下济南市采暖季PM2.5中水溶性离子变化分析  

Impact on Water Soluble Ions in PM2.5 during Heating Period in Jinan City by A Policy of Clean Energy

作　　者：魏小锋 谭路遥 孙友敏[1] 朱丽[1] 张桂芹[1] WEI Xiaofeng;TAN Luyao;SUN Youmin;ZHU Li;ZHANG Guiqin(School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, China)

机构地区：[1]山东建筑大学市政与环境工程学院

出　　处：《生态环境学报》2019年第7期1416-1422,共7页Ecology and Environmental Sciences

基　　金：山东省科技攻关计划项目(2014GSF117002);山东建筑大学博士基金项目(XNBS1310)

摘　　要：为了评价清洁能源政策对济南市采暖季PM2.5质量浓度及PM2.5中水溶性离子的影响,于2016年11月-2017年3月(2016年采暖季)和2017年11月-2018年3月(2017年采暖季)济南市区清洁能源政策实施前后两个采暖季分别采集PM2.5样品,采用离子色谱法得到了PM2.5中的8种水溶性无机离子(F^-、Cl^-、NO3^-、SO4^2-、Na^+、K^+、Ca^2+、NH4^+)的质量浓度,并对PM2.5不同污染等级水溶性离子进行了变化分析。结果表明:(1)采用清洁能源后,济南市采暖季的污染等级从轻度污染变为良,PM2.5日均质量浓度从98.34μg·m^-3降到83.48μg·m^-3,达标率上升了15.42%;(2)8种水溶性离子的总质量浓度从90.78μg·m^-3降到了67.72μg·m^-3,对比两年采暖季各离子的质量浓度发现,实施后除污染天K+和Na+的质量浓度有所增长外,其余离子质量浓度均比清洁能源使用前要低;(3)NO3^-、SO4^2-、NH4^+(SNA)在水溶性离子中占比最高,能源政策实施后,SNA的质量浓度降低了12.32%-31.71%;实施后SO42-的占比降低,NO3^-占比升高,NO3^-是最主要的二次污染离子;(4)两年采暖季的硫氧化率SOR、氮氧化率NOR值均大于0.1,说明NO3^-、SO4^2-主要来自于大气中NO2和SO2的二次转化,随着污染等级的升高,SOR和NOR基本呈现上升的趋势,尤其是在重度污染下,由于NO2对SO2的氧化反应起到很好的催化作用,SOR是清洁天的2倍;(5)采用清洁能源前后阴阳离子电荷当量(AE/CE)分别为0.76和0.96,PM2.5整体从弱碱性恢复到中性。清洁能源的使用,有效降低了各水溶性离子的质量浓度,减小了PM2.5质量浓度,改善了颗粒物的酸碱性,提高了采暖季环境空气质量。To evaluate the influence of a clean-energy policy on the atmosphere of Jinan city,PM2.5 samples were collected in urban area during two heating periods before and after implementing the policy(November 2016-March 2017 and November 2017-March2018).Eight water-soluble inorganic ions(WSII),including F^-,Cl-,NO3^-,SO4^2-,Na^+, K^+,Ca^2+,and NH4^+,in PM2.5 were analyzed using ion chromatography.The results showed that:(1)After implementing the policy,the air quality level of Jinan during heating period was improved from light pollution to good;the average concentration of PM2.5 decreased from 86.71 μg·m^-3 to 83.48 μg·m^-3;and the rate fulfilling the standard increased by 15.42%.(2)The total concentration of 8 WSIIs decreased from 90.78 μg·m^-3 to 67.72μg·m^-3.It was found that the concentrations of all ions were lower than those before the usage of the clean-energy policy,except for K+ and Na+ in some polluted days.(3)NO3^-,SO4^2-,NH4^+(SNA)accounted for the highest proportion of the WSIIs,especially in heavily-polluted days.After the policy,the proportion of SO4^2-decreased and NO3^-increased,and the later was the main secondary pollution ion.(4)SOR and NOR values in two heating periods were both greater than 0.1,indicating that NO3^-and SO4^2-mainly originated from the secondary transformation of NO2 and SO2 in the atmosphere.With the increase of pollution level,SOR and NOR usually showed an ascending trend,especially under heavy pollution.Since NO2 performed high catalytic effect on the oxidation of SO2,SOR was doubled than unpolluted day.And(5)before and after the policy,the AE/CE was 0.76 and 0.96,respectively.PM2.5 was transmitted from weak alkalinity to neutrality.The implementation of clean energy policy effectively reduced the concentrations of PM2.5 and WSII,improving the acidity and alkalinity of PM2.5,and the environmental air quality during heating period in Jinan.

关 键 词：清洁能源 PM2.5 采暖季 水溶性离子 济南市 

分 类 号：X131.1[环境科学与工程—环境科学]