补水条件改变对景观水体中沉积物氮磷释放的影响研究

Characteristics of nitrogen and phosphorus release from water sediment regarding different water replenishment approaches

以再生水(TN、TP浓度较高)和河水(水质较好)补水的人工景观湖泊沉积物为研究对象,研究补水条件改变时沉积物中污染物的TN、TP吸附释放特性.结果表明:以再生水作为补水水源时,上覆水中TN、TP均表现为前期快速下降,而后逐渐达到平衡的过程;以自来水为补水水源时,表现为沉积物中污染物向水体的释放,以再生水补水的湖泊底泥释放大于以天然地表水为补水的湖泊底泥;以再生水补水的沉积物吸附-释放临界浓度高于以河流水补水沉积物,表明以再生水补水底泥的释放风险也越大;无论是何种补水形式和沉积物的类型,扰动均表现促进沉积物中污染物释放的趋势,且促进作用的强弱与沉积物中污染物的形态有关.

The characteristics of pollutants adsorption and desorption of two pond′s sediments with different replenished water(reclaimed water and river water respectively)under static and dynamic conditions were studied.The results concluded that TN,TP showed a trend of rapid decline at the beginning and then gradually becames flat,When using the reclaimed water of the two ponds as overlying water respectively,the contaminants tend to accumulate in sediments.Sediments of the ponds using reclaimed water as overlying water release more pollutants into water bodies greater than the sediments of the ponds using the lake water.It showed that the risk of sediments of the ponds using the reclaimed water release pollutants to the overlaying water is also great.Regardless of the water type and sediment in form of the disturbance showed the trend to promote the release of pollutants in sediments,as well as the strength and shape effects related to contaminants in sediments.The results have guiding significance in city water source pollution control.