Preparation Oyster Powder Ceramsite By Shell Of Oyster And Application On Biologicall Aerated Filter Proces

With the improvement of the marine aquaculture industry and people’s attention onhealth, the demands of oyster were growing, which attendanted oyster shells piledproblems had become increasingly serious. Oyster shells were used as main rawmaterial to preparate Oyster Powder Ceramsite (OPC) in the paper, the influence ofmaterial ratio and calcination temperature on OPC’s properties were researched.Compressive strength, water absorption and other methodes were tested to determinethe optimal conditions for preparing OPC. Biological Aerated Filter (BAF) wasdesigned, which was used BioliteTM(BO), OPC, and Mixed Packing (OPC: BO=1:3,MP) as filter to treat aquaculture wastewater and dyeing wastewater. In addition,phosphorus adsorption properties of BAF were also studied.BAF was designed and used oyster shells as filler, when ammonia concentrationwas14-45mg L-1, ammonia concentration in effluent was approximately1mg L-1,ammonia removal of oyster shell BAF was good, removal rate of CODMnwas about90%. The mass loss of oyster shell was lost during operation, the amount of ammonianitrogen removal and filter loss had a linear relationship.Ratio of raw materials and the firing temperature has an important effect on theperformance of the OPC. The optimum preparation conditions of OPC were: oystershells, clay and silicate was4:2:1(mass ratio), calcination temperature was450℃,the compressive strength was2.73MP、specific surface area was4.97m2g-1, porositywas41.32%, silt content was0.71%, broken rate and the sum of the wear rate was2.03%, the index meet the demand of CJ/T299-2008, Therefore, it was the bestcondition for preparation of OPC.BO, OPC and MP were used for BAF filter to treat mariculture wastewater,respectively. When the ammonia concentration in the range of14-30mg L-1,ammonia concentration in effluent of MP BAF was about1mg L-1, the removal rateof CODMnof three BAFs was all above90%. When the ammonia nitrogen in influentwas43-45mg L-1, ammonia removal rate of BO, OPC and MP BAF was9.75%,97.80%,42.92%, respectively, the removal OPC effect of ammonia was the best, but removal of CODMndropped to68%. This is because OPC could release some calciumto buffer pH, which could ensure the progress of nitration reaction smoothly. The lossof MP, OPC and ammonia removal had a linear relationship.MP BAF was used to treat dyeing wastewater. Treatment for the removal ofturbidity and color were excellent, and when changing the influent dye concentration,turbidity and color subject to little effect.Phosphorus adsorption characteristics of OPC was studied, when oyster shellpowder, clay and Na2SiO39H2O was7:2:1(mass ratio), calcination temperature was450℃, phosphorus adsorption of prepared OPC was0.155mg g-1, OPC had a goodadsorption performance on phosphorus. The adsorption of phosphorus accorded withlangmuir isotherm adsorption model.