摘要
为了更有针对性地治理酸雨污染,利用宁波市沿海站点2006~2020年降水量、pH及化学组分观测资料,分析了其酸雨污染特征及关键的影响因素。结果表明:宁波市沿海降水年均pH值在4.40~5.37之间,酸化程度总体呈减轻趋势,但酸雨频率没有明显改善,仍呈高发态势。pH值季节变化特征明显:夏季高、冬春季低。2020年宁波市沿海降水中总离子当量浓度为335.31μeq/L,比2006年下降约52%。SO_(4)^(2-)、NO_(3)^(-)是主要阴离子,两者之和占比约30%~50%;但2016~2019年Cl^(-)占比最大。NH_(4)^(+)是主要阳离子,占12%~31%,其次是Ca^(2+)和Na^(+)。阴离子和阳离子浓度年变化升降趋势一致程度高,是酸雨污染状况难以改善的重要因素之一。由于对NOX的控制力度不及SO_(2)以及机动车尾气排放的增加,NO_(3)^(-)的致酸影响增大。宁波市沿海酸雨类型正由混合型向硝酸型转变,且已接近硝酸型的界限值。宁波市沿海Cl^(-)/Na^(+)大于海水相应值(1.167),且仍呈升高趋势,氯的排放不容忽视,生活垃圾焚烧和煤炭燃烧的增长可能是主要原因。
In order to take targeted measures to control acid rain pollution,the acid rain characteristics and the key influencing factors were analyzed based on the precipitation,pH and chemical composition data of coastal stations in Ningbo City from 2006 to 2020.Results showed that the annual average precipitation pH was between 4.40 and 5.37 and the degree of acidification showed a decreasing trend in general.but the annual frequency of acid rain did not improve significantly and still showed a high occurrence trend.The seasonal variation of pH value was obvious:higher in summer and lower in winter and spring.The total ionic equivalent concentration in the coastal precipitation Ningbo City in 2020 was 335.31μeq/L,which was about 52%lower than in 2006.and were the main anions and their concentrations accounted for 30%~50%.However,accounted for the most proportion from 2016 and 2019.The main cation was and its concentration percentage was 12%~31%,followed by and.The annual variation trends of anions and cations were highly consistent,which was one of the important reasons that the acid rain pollution was difficult to improve.The influence of increased because of the insufficient control of and the increase of vehicle emissions.Therefore,the pattern of acid rain along the Coast of Ningbo converted from mixed type to nitric acid type,and was very close to the limit value.The ratio of and was higher than the corresponding value of seawater(1.167)and still showed an rising trend.The emissions of chlorine cannot be ignored,and the increase of domestic waste incineration and coal burning might be the main reasons.
作者
徐璐
胡晓
常婉婷
郑艳
许岳庭
XU Lu;HU Xiao;CHANG Wan-ting;ZHENG Yan;XU Yue-ting(Ningbo Zhenhai Meteorological Bureau,Ningbo,Zhejiang 315202,China;Ningbo Meteorological Bureau,Ningbo,Zhejiang 315012,China;Ningbo Haishu Meteorological Bureau,Ningbo,Zhejiang 315194,China)
出处
《四川环境》
2023年第4期121-126,共6页
Sichuan Environment
基金
宁波市气象科技计划项目(NBQX2018011B)。
关键词
酸雨
PH
酸雨类型
化学组分
Acid rain
pH
the pattern of acid rain
chemical components
