三垟湿地沉积物-间隙水-上覆水界面磷形态研究

Study on the phosphorus forms in the interface of sediment-interstitial water-surface water of Sanyang wetland

沉积物与上覆水间营养物质交换,成为导致水体发生富营养化的首要化学变迁过程。分别在三垟湿地的柑橘林(S1)、景观用地(S2)和生活用地(S3)取样,研究了沉积物-间隙水-上覆水界面磷形态以及相互关系。结果表明:(1)沉积物TP增加时,间隙水PO43-和可溶性总磷(TDP)也增加。要削减磷在上覆水中的含量,控制间隙水PO34-或TDP是一良策。(2)随着沉积物铁磷、铝磷的增加,间隙水PO43-也增加。在三垟湿地沉积物中,铁磷和铝磷含量都可作为间隙水PO43-含量的指示。(3)S1、S2和S3的沉积物活性磷、间隙水TDP和上覆水TDP存在明显的浓度梯度,沉积物活性磷>间隙水TDP>上覆水TDP。说明在三垟湿地中,沉积物活性磷是磷释放的关键因子,而沉积物-间隙水界面则是磷释放的关键界面。

The nutrients exchange between sediment and surface water was the primary processes that causing the eutrophication in water body.In this paper,citrus forest（S1）,landscape land（S2） and living land（S3） in Sanyang wetland were selected as study site to investigated the phosphorus forms in the interface of sediment-interstitial water-surface water and their correlation.Results showed that the total phosphorus（TP） in sediments dominated the content of total dissolved phosphorus（TDP） and PO3-4 in interstitial water,so it was a better way to cut the phosphorus in surface water by controlling the content of TDP or PO3-4 in interstitial water.The content of PO3-4 in interstitial water was positive correlated with Fe-P and Al-P in sediments.In the sediment of Sanyang wetland,both Fe-P and Al-P could be applied as indicator of PO3-4 in interstitial water.There was a significant concentration gradient among the activated phosphorus in sediment,TDP in interstitial water and TDP in surface water,they were followed the order of activated phosphorus in sedimentTDP in interstitial waterTDP in surface water.The result indicated that in Sanyang wetland,the activated phosphorus in sediment was the key factor of phosphorus release,and interface between sediment and interstitial water was primary interface of phosphorus release.