In order to study the characteristics of suspended particulate matter(SPM)in the pre-dam and its potential impact on water quality,we investigated the spatial distribution of SPM and nutrients contents in overlying water in the upstream,midstream and downstream areas of the Dapu Harbor pre-dam system in Lake Changdang in low(December,2022),medium(April,2023)and high flow season(August,2023).We also conducted an in-situ experiment to explore the interception mechanism in pre-dam system in high flow season.The results showed that about 46.42％of NH4+-N,51.59％of TN and 36.83％TP were removed from overlying water through the pre-dam system,which play an import role on pollutes reduction.It should be noted that SPM sizes had significant effects on TOC(P=0.018)and TN concentration(P=0.011)and carbon and nitrogen contents in SPM increased with the increase of SMP sizes in surface layer of water column.The in-situ experiment revealed that TN and TP content were 2.33～5.25times and 4.53～5.72times higher in captured SPM from the surface and bottom layers of water column than in the free water body,respectively,and N and P concentrations in the water column were negatively correlated with the TN and TP concentrations in SPM,respectively.These data demonstrate that SPM as carrier can adsorb and transport pollutes,and SPM has a great influence on pollutes transformation through adsorption and precipitation.This study provided sound data that pre-dam system can improve water quality through SPM removal,especially for the treatment of high turbid water in inlet rivers of lake.
维普
万方数据