不同土地利用方式下水塘底泥氮磷和重金属的积累及释放特性  

Accumulation and Release Potential of Some Pollutants in Pond′s Mud Under Different Land Use

作　　者：章明奎[1] 王浩[1] 郑顺安[1] 

机构地区：[1]浙江大学环境与资源学院,浙江杭州310029

出　　处：《农业环境科学学报》2008年第4期1391-1397,共7页Journal of Agro-Environment Science

基　　金：浙江省自然科学基金(R306011);国家自然科学基金资助项目(40771090)

摘　　要：为了解不同土地利用方式下水塘底泥污染物的积累与释放特性及对水塘水质的可能影响,采用底泥全量化学分析、间隙水水质分析、水可溶性组分分析和水柱培养试验等综合方法研究了4个具不同土地利用特点的小型水塘底泥中氮磷和重金属等污染物的垂直分布规律及其释放特点。结果表明,不同土地利用方式下水塘底泥中氮、磷和重金属含量有较大的差异,底泥中全P和全N含量:水产养殖区>工业生活混杂区>生活区>农业区;底泥中重金属含量:工业生活混杂区>水产养殖区>生活区>农业区。底泥上层全磷、全氮、重金属全量一般高于下层,表明近年来底泥中污染物的积累呈增加趋势。但底泥中对水质起关键作用的水溶性氮、磷和重金属浓度并不一定随底泥深度增加而下降,间隙水中NH4-N的浓度一般随深度而增加,大部分底泥间隙水中磷和重金属浓度峰值出现在底泥中下层。水柱培养试验也表明,清淤(移去底泥上层)不一定能有效改善水质。Various sources may contribute to the input of pollutants to fiver and lake sediments. Possible sources are domestic and industrial wastewaters, runoff from agricultural soils and dump sites, and from atmospheric deposition. The relative importance of these sources varies with land use. To evaluate accumulation and release potential of some pollutants in pond＇s mud as affected by land use, four complete mud cores （0-50 cm） were collected from four small ponds with different land use in Zhejiang province, southeast China. The cores were cut into 10 cm layers, and analyzed for their total and water-soluble P, N and heavy metals as well as chemical compositions of pore-water. The varying-depth mud was also tested for its releasing and adsorbing capacity to N and P by means of water column incubation. The difference in pollution extent of pond＇s mud with N, P and heavy metals was noted among four land uses. The concentration of N and P in the mud samples decreased in the order of aquaculture area 〉 industry-resident mixed area 〉 resident area 〉 agricultural area, while those of heavy metals decreased in the order of industry-resident mixed area 〉 aquaculture area 〉 resident area 〉 agricultural area. The concentrations of total pollutants in the mud decreased with increasing depths. However, concentrations of water-soluble N, P and heavy metals of the mud samples did not always fellow the pattern. The concentration of NH4-N in pore-water separated from the mud samples increased generally with increasing depths, and peak concentrations of P and heavy metals in pore-water occurred in varying depth where mud pH was low, suggesting that removal of top mud could not always decrease the release of pollutant from the bottom mud. Water column incubation experiment also indicated that removal of surface mud did not modify water quality significantly. In most cases, removal of surface mud increased the concentrations of P, N and heavy metals in overlaying waters, and thus resulted in further degradation of w

关 键 词：水塘 土地利用方式 污染物积累 间隙水 清淤 

分 类 号：X524[环境科学与工程—环境工程]