摘要
杭州西湖是一个小型浅水湖泊,其底泥由上部藻骸腐泥和下部泥炭层构成。西湖底泥的显著特点是有机碳含量特别高,氮和磷含量也相当高。通过实验室和现场模拟研究,考察了pH、温度、溶解氧、氧化还原电位及上复水种类等环境因素对底泥释磷量和释磷速率的影响。上复水pH值在6.5—7.0范围内底泥释磷量最低;在较高或较低pH值时,底泥释磷量倍增。升高水温或降低上复水溶解氧浓度均能加速磷释放。实验室模拟西湖底泥最大释磷量为0.368μg/g。夏季现场模拟平均释磷速率为1.02mg/m^2·d;估算西湖底泥释磷量达1.346t/y,相当于年平均外部入湖磷负荷的36.4％。底泥释磷对西湖富营养化有着不容忽视的影响。
The sediments of the West Lake in Hangzhou, a small and shallow lake, are characterized by high organic carbon content (average 16.70%) and pretty high nitrogen content (average 0.98%). Simulation studies in the laboratory and in the field were conducted to determine the effects of various environmental parameters including pH, temperature, dissolved oxy-gen concentration, redox potential and the type of overlying water on phosphorus release rate and release capacity from the sediments. The lowest release capacity was observed in a pH range of 6.5-7.0 of the overlying water. At higher or lower pH values, the release could be redoubled. Raising the temperature or decreasing oxygen concentration in the overlying water also led to the increase of phosphorus release. The highest release capacity was found to be 0.368μg/g in the laboratory. The average release rate measured in the lake in summer was 1.02 mg/m2·d. The total phosphorus release capacity from the sediments was estimated to be 1.346 t/y which is equivalent to 36.4% of the average annual external phosphorus loading. Sediment release of phosphorus is a major contributory factor for the eutrophication of the lake.
出处
《环境科学》
EI
CAS
CSSCI
CSCD
北大核心
1992年第3期25-29,共5页
Environmental Science
基金
国家"七五"科技攻关项目
关键词
底泥
磷
释放试验
富营养化
sediments, phosphorus, eutrophication.
