西宁取暖季PM_(2.5)水溶性离子的污染特征研究  

Research on pollution characteristics of water-soluble ions in PM_(2.5) during heating season in Xining

作　　者：胡晓峰 赵露[2] 李佳 修光利 王建荣[3] HU Xiaofeng;ZHAO Lu;LI Jia;XIU Guangli;WANG Jianrong(State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Processes,School of Resources&Environmental Engineering,East China University of Science and Technology,Shanghai 200237;School of Chemical Engineering,Qinghai University,Xining Qinghai 810016;Qinghai Research and Design Institute of Environmental Sciences,Xining Qinghai 810007)

机构地区：[1]华东理工大学资源与环境工程学院国家环境保护化工过程环境风险评价与控制重点实验室,上海200237 [2]青海大学化工学院,青海西宁810016 [3]青海省环境科学研究设计院,青海西宁810007

出　　处：《环境污染与防治》2019年第1期95-100,共6页Environmental Pollution & Control

基　　金：青海省自然科学基金资助项目(No.2017-ZJ-789)

摘　　要：于2017年1—5月(取暖季)在西宁市区、郊区、农村设置采样点采集PM_(2.5)样品,利用离子色谱法测定PM_(2.5)中水溶性无机离子浓度。结果表明:取暖季西宁大气PM_(2.5)日均质量浓度为(55.98±52.66)μg/m^3,呈现明显的市区>郊区>农村的浓度变化特征。PM_(2.5)中水溶性离子质量浓度之和占PM_(2.5)质量浓度的36.3%,水溶性离子平均浓度大小为SO_4^(2-)>NO_3^->NH_4^+>Na^+>Cl^->C_2O_4^(2-)>Ca^(2+)>F^->K^+>Mg^(2+);取暖季西宁大气硫氧化率(SOR)和氮氧化率(NOR)平均值分别为0.21、0.13,表明SO_4^(2-)、NO_3^-主要由二次转化形成,PM_(2.5)中NO_3^-/SO_4^(2-)(质量浓度比)为0.75,阳离子与阴离子电荷摩尔数比值为0.89,表明燃煤是PM_(2.5)主要贡献源,颗粒物总体呈酸性。后向轨迹分析表明,重污染期间西宁PM_(2.5)及其中水溶性离子的浓度变化不仅受本地污染源的影响,也受外来气团输送的影响。The PM 2.5 samples were collected at urban,suburb and rural area of Xining from January to May(heating season)of 2017.The water-soluble inorganic ions in PM 2.5 were determined by ion chromatography method.The results showed that during heating season,the daily mean mass concentration of PM 2.5 was(55.98±52.66)μg/m 3 in Xining,which presented significantly characteristics of urban >suburb >rural area.The total mass concentration of the water soluble ions determined in this study accounted for 36.3%of PM 2.5,the average concentration of water-soluble ions occurring the following sequence:SO4^2- >NO3^- >NH4^+ >Na^+ >Cl%- >C2O4^2- >Ca^2+ >F^- >K^+ >Mg^2.The average sulfur oxidation rate(SOR)and nitrogen oxidation rate(NOR)of Xining atmosphere were 0.21,0.13 separately,which meant the SO4^2-,NO3^- in PM 2.5 were mainly formed by secondary transformation,NO3^-/SO4^2(mass concentration)of PM 2.5 was 0.75 and the mole ratio of anion charge to cation charge was 0.89,demonstrating that coal combustion was still the dominating source of PM 2.5 and the particle were generally acidic.Backward trajectory analysis indicated that the PM 2.5 and water soluble ion in Xining during heavy pollution were not only influenced by the local pollution sources,but also affected by foreign air transportation.

关 键 词：PM2.5 水溶性离子 污染特征 西宁 

分 类 号：X513[环境科学与工程—环境工程]