北京地表水冬季水化学特征和质量现状

Water Chemical Features and Quality Status of Beijing Surface Waters in Winter

该研究通过对冬季北京市地表水的p H、电导率、阴阳离子、TOC、有机氯农药(OCPs)含量调研,了解其水化学特征和质量现状。结果表明:北京地表水为弱碱性,p H范围为6.27~9.15,北京东南部湖群水的电导率要大于西北部湖群。Na+和Ca2+为主要阳离子,占总阳离子的78.2%(66%~87%),其平均值分别为69.6 mg/L和73.4 mg/L。SO42-和Cl-为主要阴离子,占总阴离子的86.7%(49%~98%),其平均值分别为126.2 mg/L和90.6 mg/L。绝大部分湖泊水体TOC含量小于10 mg/L,质量状况尚可,个别湖泊受到不同程度的OCPs污染。综合结果表明,由于水体周边人类活动频繁,扰动了北京城市水体的天然水化学特征,今后应在生态、工农业生产、生活等方面采取有效措施,控制水体污染。

This study aims to sample and analyze p H, electrical conductivity, anions and cations, TOC and organic chlorine pesticides(OCPs) content in surface waters of Beijing in winter and thus evaluate their water chemical features and quality status. The results show that Beijing lakes' water are weak alkaline(p H=6.27~9.15). The electrical conductivity of water in the southeastern lakes is greater than those of the northwestern lakes. Na+and Ca2+are the principal cations in the surface water and the mean values are 69.6 mg/L and 73.4 mg/L, respectively. The sum of Na+and Ca2+accounts for about 78.2%(66%~87%) of the total cations. SO42-and Cl-are the principal anions in the surface water and the mean values are 126.2 mg/L and90.6 mg/L, respectively. The sum of SO42-and Cl-accounts for about 86.7%(49%~98%) of the total anions. The concentration of TOC is less than 10 mg/L in most of the lakes, with good status. A few lakes have been polluted by OCPs at different lev-els. The result shows that the natural water chemistry characteristics have been disturbed by frequent human activities. It is suggested that water pollution should be controlled in terms of ecology, agriculture and industrial production etc.