威海市区大气降水化学特征及来源研究

Chemical Characteristic and Source Assessment of Precipitation in Weihai

以2019年3月-2020年2月威海市区降水数据为基础,分析了降水化学特征,结果表明:样品pH值介于5.60~6.63之间,雨量加权均值为6.05,整体呈弱酸性,大部分酸性物质能被碱性成分中和;电导率变化范围为6.8μS/cm~121μS/cm,加权均值为36.7μS/cm;主要阴离子是Cl^(-)、SO^(2-)_(4)和NO^(-)_(3),分别占离子总量的17.7%、15.8%和13.5%,主要阳离子是Na^(+)、Ca^(2+)和NH^(+)_(4),分别占离子总量的15.4%、14.9%和14.5%,离子浓度季节性变化呈冬春高、夏秋低态势。利用相关性和富集系数分析各离子的潜在来源,结果显示SO^(2-)_(4)和NO^(-)_(3)主要来源于人为源,Cl^(-)主要来源于海源和人为源,Ca^(2+)主要来自于陆源和人为源,Mg^(2+)和K^(+)同时受陆源、人为源和海源的影响。

The chemical characteristic of precipitation in Weihai was studied on the basis of data during the period from March 2019 to February 2020.The results showed that the pH of samples varied from 5.60~6.63,with the volume-weighted average of 6.05,the local rainwater was weakly acidic,and most of acidic components in precipitation could be neutralized by alkaline materials.The conductivity of samples varied from 6.8μS/cm-121μS/cm,with the volume-weighted average of 36.7μS/cm.Cl^(-),SO^(2-)_(4)and NO^(-)_(3)were the major anions,with the percent contribution to the total ions of 17.7%,15.8%and 13.5%,respectively.Na+,Ca^(2+)and NH^(+)_(4)were the main cations,with the percent contribution to the total ions of 15.4%,14.9%and 14.5%,respectively.The seasonal variations of ions showed that the concentrations were higher in winter and spring than in summer and sutumn.The potential sources were analyzed by the correlation and enrichment factors.The Results indicated that SO^(2-)_(4)and NO^(-)_(3)were primarily attributed by the human activities,Cl^(-)ariginated from sea sources and anthropogenic activities,Ca^(2+)came from terrestrial sources and human activities,Mg^(2+)and K+were attributed by terrestrial sources,human activitiesandsea sources.