Abstract: Submersed plant Potamogeton crispus was used to construct a holistic system connecting the shallow layer to the deep layer of water.When sandy water flows through the shallow layer to the deep one,effect of P.crispus on concentration of suspended mud and sand(MS) in different depth layers and sedimentation of MS.Results show that P.crispus reduced content of MS,and the longer they stayed with the flow,the greater the effect.The average settlement of MS in P.crispus system was 65.7 g·m^-2,39.4% higher than in CK.MS sorption on the surface of P.crispus is a dynamic process of "adsorption-settlement-adsorption" ranging from 3.26 to 5.69 g·kg^-1,which was related to biomass per unit area of P.crispus.Therefore,submerged plant P.crispus may play an important role in self-purification of water bodies in winter.

Key words: suspended sediment, Potamogeton crispus, sedimentation, adsorption, hydraulic retention time