贵阳市红枫湖湖泊沉积物地球化学与环境质量评价

GEOCHEMISTRY AND ENVIRONMENTAL QUALITY ASSESSMENT OF HONGFENG LAKE SEDIMENTS,GUIYANG CITY

通过贵阳市红枫湖多目标地球化学调查,发现红枫湖湖泊沉积物pH值为7.3～7.5,属中偏碱性环境。沉积物具有富营养化趋势明显,C、Corg、N、S、F、P等含量较高且富集度大,存在As、Cd、Hg等重金属安全隐患,其中As含量为(34.6～52)×10-6,平均值40.8×10-6,超过国家土壤环境质量三级标准的特点。按每月一次对湖水水质进行一年期观测,发现湖水pH值为7.5～8,属中偏碱性环境,湖水总N长期超标。湖泊沉积物地球化学环境极可能对湖水水质产生影响,因此通过湖泊沉积物和水体的综合研究,可以为贵阳市重要水源地生态环境保护提供科学建议。

Multi-purpose geochemical survey in the Hongfeng Lake of Guiyang City shows that its pH values are between 7.3 and 7.5 suggesting an intermediate and somewhat alkaline environment.Lacustrine sediments are characterized by entrophication,high concentration and enrichment of C,Corg,N,S F and P and hidden dangers of heavy metals such as As,Cd and Hg.The concentration of As is between（34.6～52）×10-6,40.8×10-6 on average,exceeding the Grade III of Environmental Quality Standard for Soils.According to year-round monitoring and monthly sampling,the pH values of lake water are between 7.5 and 8.0,also implying an intermediate and somewhat alkaline environment,and the total N exceeds Environmental Quality Standards for Surface Water.The authors consider that the water quality of the lake may be impacted by geochemistry of lake sediments,and hence put forward some proposals for eco-environmental protection of important water source sites in Guiyang City on the basis of a comprehensive study of sediments and water in the lake.