义乌市岩口水库底泥特征、营养盐含量及污染现状分析

Analysis of Characterization, Nutrient Content and Pollution Status of Sediment in Yankou Reservoir, Yiwu City

2014年2月至11月每季度一次对浙江省义乌市岩口水库底泥孔隙率、含水率、总氮(TN)、总磷(TN)、总有机质(TOM)含量进行了调查,,分析了底泥的特性、营养盐的来源、相互关系及影响其分布的因素,合理评价了底泥的肥力和污染现状。结果表明:岩口水库底泥孔隙率、含水率、TN、TP和TOM的平均值分别为(73.54±7.87)%、(87.84±7.01)%、(3 898±1315.83)mg/kg、(900±632.19)mg/kg和(136±28.47)g/kg。通过比较碳/氮(C/N)比值发现,底泥中TOM主要来源于陆源污染物;各站间不同季节底泥TN、TP、TOM的含量受陆源污染物输入、水动力条件等影响;相关性分析表明,底泥中TN和TOM显著相关;有机指数评价底泥肥力结果表明底泥肥力处于肥污染状态;生源要素法评价结果显示底泥总氮污染较为严重,总磷污染程度较低。

The porosity,moisture, total nitrogen（TN）, total phosphorus（TP） and total organic matter（TOM）content in sediment of Yankou reservoir were investigated from February to November 2014, which aimed to analyze the characterization of sediment and source, correlation, affecting factors of nutrients in sediment. The results showed that the average of porosity, moisture, TN, TP and TOM content in sediment was（73.54 ±7.87）%,（87.84±7.01）%,（3 898±1 315.83） mg/kg,（900±632.19） mg/kg and（136±28.47） g/kg, respectively. The contents of TN, TP and TOM in different sites and different seasons were mainly influenced by terrigenous inputs and hydrodynamics. The TOM mainly came from terrigenous pollutants through analyzing the C/N ratio of different organisms. There were significant correlation between TN and TOM. The sediment was at serious pollution sta-tus according to the fertility index. 55.6% single standard indexes of total phosphorus were below 1, which indicated that the content of the total phosphorus was relatively low. However, the content of total nitrogen was high, the standard indexes ranged from 4.81 to 12.40, which indicated that the nitrogen pollution was relatively serious.