摘要
天山北坡是重污染天气消除攻坚战的重点区域,为了解该区域冬季大气重污染期间NH_(4)^(+)污染特征及其对PM_(2.5)浓度的贡献,2020年12月—2021年1月在该区域典型工业城市石河子市城区对气态NH_(3)和PM_(2.5)中水溶性离子的浓度进行了连续监测,分析了不同空气质量等级下PM_(2.5)中NH_(4)^(+)浓度和NH_(3)-NH_(4)^(+)气固转化率的变化以及NH_(4)^(+)的赋存形式.结果表明:(1)监测期间,石河子市大气PM_(2.5)、NH_(4)^(+)和其他阳离子的平均浓度分别为164、25.3和3.60μg/m^(3),NH_(4)^(+)浓度是其他阳离子总浓度的7.0倍;NH_(4)^(+)浓度在PM_(2.5)浓度中的占比为15.4%,仅次于SO_(4)^(2-)和NO_(3)^(-).NH_(4)^(+)和其他阳离子浓度均随污染加重逐渐升高,但NH_(4)^(+)浓度的增幅远大于其他阳离子.(2)随着污染加重,NH_(3)-NH_(4)^(+)气固转化率逐渐升高,其在优良天、轻度和中度污染天、重度及以上污染天分别为0.23、0.51、0.69.整体上,NH_(3)-NH_(4)^(+)气固转化率与PM_(2.5)和NH_(4)^(+)浓度均呈显著正相关,与气态NH_(3)浓度和大气温度均呈负相关.(3)石河子市冬季大气NH_(4)^(+)充足,主要以(NH_(4))_(2)SO_(4)的形式赋存,剩余NH_(4)^(+)以NH_(4)NO_(3)和NH_(4)Cl的形式赋存.研究显示,天山北坡区域冬季大气重污染期间NH_(3)-NH_(4)^(+)气固转化率和NH_(4)^(+)浓度均显著升高,大气污染防治工作在关注SO_(2)和NO_(x)污染控制的同时,也需要加强对NH3的污染治理.
The north slope of Tianshan Mountains is one of the important areas in the national wide battle to eliminate heavy pollution weather.To investigate the pollution characteristics of atmospheric ammonium ion(NH_(4)^(+))and its contribution to PM_(2.5) concentration during the period of heavy air pollution in winter,the concentrations of gaseous ammonia(NH_(3))and water-soluble ions in PM_(2.5) were monitored in December 2020 and January 2021 in Shihezi City,a typical industrial city on the north slope of the Tianshan Mountains.The variations of atmospheric NH_(4)^(+)concentration,NH_(3)-NH_(4)^(+)gas-solid conversion rate,and the existence forms of NH_(4)^(+)under different air quality levels were studied.The results showed that:(1)During the monitoring period,the concentrations of PM_(2.5),NH_(4)^(+),and other cations(except NH_(4)^(+))were 164,25.3,and 3.60μg/m^(3),respectively.NH_(4)^(+)concentration was 6.0 times higher than other cations,accounting for 15.4% of PM_(2.5) concentration,only lower than SO_(4)^(2-)and NO_(3)^(-).The concentrations of NH_(4)^(+)and other cations increased with the escalated pollution,but the increase of NH_(4)^(+)was greater than that of other cations.(2)With the aggravation of air pollution,NH_(3)-NH_(4)^(+)gas-solid conversion rate increased gradually.The average conversion rates on clean days,light and moderate pollution days,and heavy and serious pollution days were 0.23,0.51 and 0.69,respectively.The conversion rate was positively correlated with PM_(2.5) and NH_(4)^(+)concentration,and was negatively correlated with gaseous NH_(3) concentration and temperature.(3)The atmospheric NH_(4)^(+)was high in Shihezi in winter,and was mainly in the form of(NH_(4))_(2)SO_(4),and the remaining NH_(4)^(+)existed in the form of NH_(4)NO_(3) and NH4Cl.The study showed that the NH_(3)-NH_(4)^(+)gas-solid conversion rate and NH_(4)^(+)concentration increased significantly during the heavy air pollution period in winter on the north slope of Tianshan Mountains,and it is necessary to pay attention to NH_(3) pollution prevention while focusing on the control of SO_(2) and NO_(x) pollution.
作者
何凯杰
李刚
程苗苗
李维军
杨小阳
李斌
何友江
HE Kaijie;LI Gang;CHENG Miaomiao;LI Weijun;YANG Xiaoyang;LI Bin;HE Youjiang(North University of China,Taiyuan 030051,China;State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Shihezi Ecological and Environmental Monitoring Station,Eighth Division of Xinjiang Production and Construction Corps,Shihezi 832099,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2023年第5期887-894,共8页
Research of Environmental Sciences
基金
大气重污染成因与治理攻关项目(No.DQGG202152)。
