Research Of Quantitative Relationship And Flux Changes Between Particle Phosphorus And Suspended Sediment In Middle Reaches Of Yangtze River

Three Gorges Reservoir is a remarkable outstanding hydraulic project all around theworld, there are lots of researches on suspended sediment environmental effects in themiddle reaches of the Yangtze River. Based on previous researches, through a serials ofcompleted interior dynamic adsorption experiments, this paper analyzes the size of themiddle reaches of the Yangtze River suspended sediment, suspended sedimentconcentration and phosphorus concentration influence on the sediment particles adsorbedphosphorus and systematic analysis of changes in midstream particulate phosphorus ofYangtze River over the next20years, meanwhile, pointing out the impact of the nutrienttransport on the Yangtze River ecological environment in the Three Gorges reservoir.The main contents and conclusion include the following aspects:（1） By summarizing the status of the middle reaches of the Yangtze River spatialand temporal distribution of suspended sediment and particulate phosphorus, the resultsshow, since the operation of Three Gorges Reservoir, suspended sediment and particulatephosphorus fluxes have reduced greatly from Yichang to Hankou. And vary seasonally,its transportation through the wet period accounted for over80%of the year. but it’s alower peak in recent decades.（2） The middle reaches of the Yangtze River through sediment and particulatephosphorus indoor adsorption experiments reveal the total amount of adsorption andadsorption capacity per unit mass of sediment with suspended sediment concentrationrule, sediment grain size, phosphate concentration and temperature. The results show, thetotal amount of adsorption increases with the initial concentration of phosphorus andsediment concentration increases; While Unit mass of sediment adsorption capacityincreases with the sediment concentration and particle size decreases, And increases withtemperature and initial phosphorus concentration increase; The maximum adsorptioncapacity to be determined.（3） Freundlich adsorption isotherm and Langmuir isotherm are expressed thatsediment phosphorus adsorption equilibrium distribution of phosphorus in therelationship between water and sediment, Both of the fitting results meet the accuracy requirements respectively, while Langmuir model water phase only consider twovariables, sediment concentration and equilibrium phosphorus concentration, and whichis more convenient for the latter to fit.（4） Based on the measured data, calibration and validation of the middle reaches ofthe Yangtze River particulate phosphorus and suspended sediment quantitativerelationship, Cs=k*S^1-n*C_w(1+k’*S^-n*C_w)，, According to the equation, themiddle reaches of the Yangtze River for the next,20years particulate phosphorus fluxchanges were predicted. Which shows that the middle Yangtze particulate phosphorusflux building a database less than the previous levels in20years, resulting in lack of damwater phosphorus, which to some extent will inhibit the grow of four major Chinesecarps and other aquatic organisms.（5） The prospect of the Quantitative relationship of the temperature and particle sizewith sediment adsorption capacity, also the impact of cross-strait sewage, rural non-pointsource pollution.