The Phosphorus Forms And The Adsorption Characteristics In Different Grain Size Sediment And Their Relation To The Nutrtional Status Of Yaohu Lake

On the basis of the early research for YaoHu eutrophication status and its pollution characteristics.First,the distribution characteristics of different nitrogen and phosphorus forms,and nitrogen and phosphorus adsorption thermodynamics behavior are investigated in the different grain size sediment.The relationship between the nutritional status in water and the main nitrogen and phosphorus forms in the different grain size sediment are researched.And the relationship between the nutritional status in water and the nitrogen and phosphorus adsorption parameters in the different grain size sediment are done.On this basis,Screening the optimal parameter index of grain size in sediment,nitrogen and phosphorus forms,nitrogen and phosphorus adsorption parameters.The optimal parameter indicators of the principal components are built using the principal component analysis.The total effects of the sediment nitrogen and phosphorus forms is further studied on the aquatic nutrition status.And a comprehensive indicator of the water nutritional status(this item called: comprehensive sediment factor)affected by sediment nitrogen and phosphorus forms is put forward.This provide theoretical support and decision-making basis for further research on the circulation mechanism of the interface between sediment and the water phosphorus and lake eutrophication mechanism in YaoHu.And its study methods has great value in academic and practice.Major conclusions were described as follows:1.The mass fraction of different grain size particle was in the order of silt and clay>fine sand>coarse sand.Silt and clay were found to be the major grain size composition in sediments,and its average mass fraction was 73.87%.And The sediments of fine sand and silt clay particle distribution have great difference in the lake;2.The content of TN,total transferable nitrogen,IEF-N,WAEF-N,SAEF-N,SOEF-N had the same change trend in different grain size for sediments at different sites.The rank order of transferable nitrogen forms was SOEF-N>IEF-N>SAEF-N>WAEF-N.The content of different nitrogen forms in different grain size for sediments at same sites was in the order of fine sand>coarse sand> silt and clay.With the change of sediment grain sizes from coarse to fine,the adsorption property of Fe/Al-P was enhanced.The relative ratio of various nitrogen factions in different grain size for sediments at different sites had the same change trend.The relative ratio of various nitrogen factions in different grain size for sediments at same sites was in the order of silt and clay>fine sand>coarse sand.With the change of sediment grain sizes from big to small,the contribution rate of grain size sediments on the total content ofnitrogen forms was big;3.The content of TP,Fe/Al-P,and OP had the same change trend in different grain size fraction sediments at different sites.The rank order of phosphorus forms was Fe/Al-P>OP.The maximum proportion of Fe/Al-P to TP was 66.71%,the minimum was 39.56%.The content of TP,Fe/Al-P,and OP in different grain size fraction sediments at same sites was in the order of fine sand>coarse sand> silt and clay.With the change of sediment grain sizes from coarse to fine,the adsorption property of Fe/Al-P was enhanced.The relative ratio of various phosphorus factions in different grain size fraction sediments at different sites had the same change trend.The relative ratio of various phosphorus factions were in the order of silt and clay>fine sand>coarse sand in different grain size for sediments at same sites.The maximum relative ratio of various phosphorus faction was 82.62% in silt and clay,the minimum was55.31%.With the change of sediment grain sizes from large to small,the contribution rate of grain size sediments on the total content of phosphorus forms was large;4.The rate,efficiency and maximum amount of sorption of ammonium on the different particle size faction sediments at different sites have similar trend.The size order were all fine sand>coarse sand> silt and clay.The adsorption of ammonia nitrogen on sediment mainly occurred within 0~2 h.The modified Elovich model was the optimal model for describing the sorption kinetics of ammonia nitrogen on sediment.The Henry model can well describe the results of the ammonium sorption isotherms at low initial concentration of ammonia nitrogen in different grain size sediments;The data of the ammonium sorption isotherms at high initial concentration can be fitted by the linear form of Langmuir model;The adsorption-desorption equilibrium concentration of ammonia nitrogen varied from 0.23mg/L~0.67mg/L in different grain size sediments,the maximal ammonium sorption capacity ranged from1227.10mg/kg~1372.98mg/kg.ENC0 were very significant positive correlation with NAN,and ENC0 depended on NAN.The maximum amount and efficiency of sorption of ammonium,ENC0,NAN had closely correlation with LOI,graded composition,TN and TP.5.The rate,efficiency and maximum amount of sorption of phosphorus on the different particle size faction sediments at different sites have similar trend.The size order were all fine sand>coarse sand> silt and clay.The adsorption of phosphorus on sediment mainly occurred within 0~10h.The modified Elovich model was the optimal model for describing the sorption kinetics of phosphorus on sediment.The Linear model can well describe the results of the phosphorus sorption isotherms at low initial concentration of phosphorus in different grain size sediments;The data of the phosphorus sorption isotherms at high initial concentration can be fitted by the linear form of Langmuir model;The adsorption-desorption equilibrium concentration of phosphorus varied from 0.16mg/L~0.30mg/L in different grain size sediments,the maximal phosphorus sorption capacity ranged from572.19mg/kg~705.20mg/kg.EPC0 were very significant positive correlation with NAP.The maximum amount and efficiency of sorption of phosphorus,EPC0,NAP had closely correlation with graded composition,TN,TP and OP.6.TN,IEF-N,SOEF-N of the different particle size faction sediments had positivecorrelation with TN and ammonium nitrogen of water in lake,respectively,and had a remarkable positive correlation with Chla;TP,Fe/Al-P and OP of the different grain size sediments had positive correlation with TP,Soluble phosphate and Chla of water in lake,respectively;NAN,ENC0,maximal ammonium sorption capacity of the different particle size faction sediments had a remarkable positive correlation with ammonium nitrogen and Chla in water;NAP,EPC0 of the different grain size sediments had a remarkable positive correlation with soluble phosphate in water;The maximal phosphorus sorption capacity had positive correlation with Chla of water in lake;The comprehensive sediment factors were TN?Fe/Al-P?SOEF-N?rate of ammonium nitrogen and TP.