多重扰动对湖泊内源磷迁移转化的影响

Impacts of Multiple Disturbance on Migration and Transformation of Endogenous Phosphorus in Lake

为了阐明多重扰动因素对内源磷迁移转化的影响,以太湖梅梁湾沉积物为研究对象,借助Rhizon间隙水采样技术、Unisense微电极系统等技术,研究了扰动下泥水两相间溶解氧、不同形态磷、铁离子等变化规律.结果表明,与对照实验相比,河蚬的出现致使沉积物内部溶解氧含量降低.扰动致使间隙水中DIP的峰值区域由3~4 cm迁移至4~5 cm,暗示了摇蚊幼虫和河蚬的引入使得DIP再生的＂活跃区域＂更深入泥层.并且,河蚬和藻类的出现进一步降低了间隙水中DIP的含量,其主要来源于NH4Cl-P的释放,去向为上覆水和形成Fe/Al-P.随着扰动因素的增加,NH4Cl-P转化为Fe/Al-P的比重也逐渐增加（由44%增至59%）.

This work aimed to clarify the influence of multiple disturbance factors on the migration and transformation of endogenous phosphorus. In this experiment,the sediment of Meiliang Bay in Taihu Lake was studied as the major research object. With the help of Rhizon sampling technique,Unisense microelectrode system and so on,this experiment studied the change regularities of dissolved oxygen between sediment and water interface,different forms of phosphorus and iron ions under disturbance. The results indicated that the dissolved oxygen content in sediment decreased in the presence of Corbicula fluminea as compared with the control experiment.Disturbance made the peak area of DIP in interstitial water to migrate from 3-4 cm to 4-5 cm,which suggested that the＂active region＂of DIP regeneration went deeply into sediment with the appearance of Chironomus plumosus and Corbicula fluminea. Meanwhile,the existence of Corbicula fluminea and algae further reduced DIP in the interstitial water. That was because the released NH4Cl-P was transferred to phosphorus in overlying water and Fe / Al-P. With the increase of disturbance factors,the transformation ratio from NH4Cl-P to Fe / Al-P also increased gradually（ from 44% to 59%）.