The Preparation Of Diatomite/Zeolites Composite Absorbent And Its Study On The Simultaneous Removal Of Ammonium And Phosphate

Through compounded, the diatomite/zeolite powder adsorption materials anddiatomite/zeolite particle adsorption materials were prepared in this paper, useddiatomite and zeolite as raw materials. The optimum preparation process conditionswere determined by the studies of mixing ratio, roasting temperature and roastingtime, and in these conditions, compound adsorption materials were obtained, withhigh nitrogen and phosphorus removal rate. The effects of wastewater in differentsituations to nitrogen and phosphorus removal rate were also discussed. On the basisof a series of static adsorption experiments, the nitrogen and phosphorus adsorptionmechanism of the compound materials in wastewater was studied. The X-raydiffraction (XRD), scanning electron microscopy (SEM), Fourier transform infraredspectroscopy (FTIR), density and particle size analytical technique were used tocharacterize the adsorption materials.The experimental results showed that:(1) The optimum preparation process conditions for powder adsorption materialswas a mixing ratio of5:5, a roasting temperature of600℃,a roasting time of90min;the optimum preparation process conditions for particle adsorption materials was amixing ratio of6:4, a roasting temperature of700℃,a roasting time of90min,15%additive.(2) The optimum conditions that the powder adsorption materials removednitrogen and phosphorus in wastewater were pH=7, the initial concentration of NH4+was40mg/L, the initial concentration of P was5mg/L, the adsorption time of240min, the usage of adsorption materials was20g/L; the optimum conditions that theparticle adsorption materials removed nitrogen and phosphorus in wastewater werepH=7, the initial concentration of NH4+was50mg/L, the initial concentration of Pwas40mg/L, the adsorption time of360min, the usage of adsorption materials was50g/L.(3) Being regenerated and reused for five times, the particle adsorption materialsof regeneration still had good adsorption ratio. The phosphorus removal ability couldreach99%that of the fresh adsorption materials, it was nearly recovered completely. (4) The dynamic adsorption experiments results showed that the pseudo secondorder reaction would describe the nitrogen and phosphorus adsorption process ofpowder and particle adsorption materials more accurately; the thermodynamicsindicated that powder adsorption materials and particle adsorption materials ofnitrogen and phosphorus adsorption were of the endothermic reaction; in the processof isothermal adsorption test, powder materials of phosphorus adsorption conformedto the Langmuir equation, particle adsorption materials for nitrogen and phosphorusadsorption were suitable for Freundlish equation.(5) The characterizations of compound adsorption materials showed thatdiatomite and zeolite have well composite effects.