洪泽湖表层底质营养盐的形态分布特征与评价

为揭示洪泽湖底质的营养盐空间分布特征,于2008年6月采集了该湖具有代表性的10个点位的表层底质,测定了其有机质、总氮、有机氮、氨氮、硝氮、总磷、无机磷、铁铝-磷、钙-磷等的含量.结果表明,底质中的有机质和总氮有很好的相关性,且有机氮约占总氮的90%,说明碳、氮有同源性;底质中的无机磷约占总磷的70%,而其中钙-磷占无机磷的比重较大;洪泽湖底质有机质与总氮,有机氮,总磷的空间分布特性极为相似,属洪水冲刷型堆积模式(Turbidity Flood Model方式);通过C/N域值得知沉积物中有机物主要来源为生物沉降.通过用有机指数评价法和有机氮评价法对洪泽湖表层底质的分析表明,洪泽湖底质除局部区域如龙集乡北表现为一定程度的有机氮污染外,整体处于清洁至尚清洁范畴.

Spatial Distribution Characteristics of Surface Sediments Nutrients in Lake Hongze and Their Pollution Status Evaluation

In order to illuminate nutrient spatial distribution characteristics in surface sediment of Lake Hongze, sediment samples at 10 representative sampling stations were collected in June of 2008, and concentrations of organic matter, total nitrogen, organic nitrogen, ammonia nitrogen, nitrate, total phosphorus, inorganic phosphorus, Al-Phosphorus, and calcium-Phosphorus in sediment of each station were measured. Analyze showed that: organic matter and total nitrogen are significantly correlated, and organic nitrogen occupies 90% of total nitrogen, which means that carbon and nitrogen were from the same source; Inorganic phosphorus is the majority (70%) of total phosphorus, and the calcium-Phosphorus accounts for a large percentage of inorganic phosphorus; The spatial distribution pattern of organic matter in the lake is very similar with that of total nitrogen, organic nitrogen and total phosphorus, which belongs to a typical sediment distribution pattern called Turbidity Flood Model. The C/N analysis showed that the main sources of organic matter in surface sediments are from the sedimentation of biomass in its water column. By organic matter index evaluation standards and organic nitrogen evaluation standards, the pollution levels of sediment at each sampling stations in the lake were evaluated at clean category, except that at north part of Longji, which was polluted by organic nitrogen.