温榆河北京段水体和沉积物中主要水化学离子及重金属特征

Water chemical ions and heavy metal characteristics of water and sediment in Beijing section of Wenyu River

在对1980 年- 2010 年温榆河水环境质量资料分析的基础上, 通过现场调查取样, 分析了温榆河离子特征、水质变化趋势以及水体与沉积物污染物的相关性.结果表明, 2013 年温榆河Na^＋ 、Ca^2＋ 、K^＋ 、HCO3^- 含量较1980 年-2006 年呈上升趋势, Cl^- 、SO4^2- 呈下降趋势, Mg＋ 含量较稳定, 水化学类型由CCaⅡ 转化为CNaI, 河水矿化度呈增大趋势的同时也向碱化发展.NH4^＋ -N 和硝酸盐仍为温榆河及各支流的主要污染物, 超标倍数虽降低, 但依然在2- 7 倍范围内, 沉积物重金属中仅Cr 和Cd 地累积指数在0- 1 之间, 处于轻度污染水平.温榆河北京段水体与沉积物污染物间相关性显著, 氨氮、硝酸盐以及Cr、Pb 呈显著正相关, Cd、As 呈显著负相关, 其中Pb 的相关性最为显著.

On the basis of data analysis of water environmental qualit y in Wenyu River f rom 1980 to 2010, t he ion characteristics, water quality variat ion trend, and the correlation betw een water and sediment w ere analyzed through field sampling. The results show ed that(1) Na+ , Ca2+ , K + , and HCO3 - contents are higher in 2013 compared t o those from 1980 to 2006, while Cl- and SO 4 2- content s are lower in 2013 and M g+ content is relatively stable in the Wenyu River; (2) water chemistry typevaries from CCa II to CNaI, indicating an increasing trend of salinity and alkaline; (3) NH4 +- N and nitrates are the main pollutants in the We-nyu River and its tributary. Although the over-standard ratio decreases over t he years, it is still in the range of 2 to 7; (4) only Cr and Cd of the heavy met al in the sediment have the cumulative index betw een 0 and 1, w hich indicates that the sediment pol-lut ion level is light; and(5) wat er and pollutants in the sediment have significant correlations in the Wenyu River, such that NH 4 +-N and nitrate show posit ive correlations w ith Cr and Pb w hereas Cd and As show negative correlations wit h Cr and Pb, and the correlation wit h Pb is the strongest.