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环境科学 2008
Influencing Factors of Calcite Active Barrier System to Control Phosphorus Release from Sediments
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Abstract:
Influencing factors of calcite active barrier system to control phosphorus release from sediments were researched,including barrier thickness,Ca~(2 ) of overlying water,temperature,calcite's grain size and artificial aeration.The results show that the calcite barrier can effectively control phosphorus release from sediments under anaerobic conditions,and its efficiency was influenced by barrier thickness,Ca~(2 ) concentration of overlying water,temperature,calcite's grain size and artificial aeration.The efficiency of calcite barrier to control phosphorus release from sediments will increase with the increment of Ca~(2 ) concentration of overlying water and barrier thickness.Application of 12.7(kg/m~2) calcite active barrier system resulted in 56% reduction of phosphorus flux from sediment for 72 days;however 99% reduction was obtained by 38.2(kg/m~2) calcite active barrier system.When the Ca~(2 ) concentration of overlying water increased from 1 (mmol/L) to 5 (mmol/L),the phosphorus concentration was reduced by about 36% in the 72~(th) day.In comparison to low temperature,high temperature was disbennifit to control phosphorus release from sediments by a thin calcite barrier.The smaller the grain sizes of calcite,the more efficient the calcite barrier.The ammonia and phosphorus release rate from sediments under calcite barrier will be decreased by aeration.