Performance Study Of Phosphate Removal With Zinc Oxide And Zinc Oxide Modified Quartz Sand

In recent years, zinc oxide has received widespread attention because of its properties of environment-friendly, large specific surface areas, adsorption properties and catalytic properties. Granular quartz sand with porous structure, low cost, easy recycling and water treatment filter is also widely used. The report on zinc oxide adsorbed phosphorus has been not seen commonly, and this paper intends to study the loading of zinc oxide onto surface of granular quartz sand to prepare zinc oxide modified quartz sand, and investigate phosphate removal performance of both zinc oxide and zinc oxide modified quartz sand to enhance both in the field of water treatment.In this paper, zinc oxide and zinc oxide modified quartz sand, which were synthesized by the thermal decomposition method, were used to study the optimum conditions of phosphorus removal; investigate the regeneration ability of zinc oxide modified quartz sand.Through this paper, we can get the following conclusions:Zinc oxide has a good phosphate removal ability in water and wastewater. Zinc oxide, at the conditions of adsorbent mass of0.01g/25mL and phosphate concentration of1mg P/L,5mg P/L,10mg P/L, had the phosphate removal efficiency of100%,100%,90%in3h, respectively. Thermodynamic analysis showed that phosphorus adsorption onto zinc oxide was a spontaneous process, and elevating temperature could be enhanced adsorption removal efficiency The maxmium phosphate adsorption capacity was168.4mg/g, which obtained from the fitting of Langmiur model. Initial solution pH had a significant effect on phosphate removal efficency, which decreased with pH increasing. And the pHpzc of ZnO was8.4through the pH-drfit method. The adsorption process can be divided into two stages:fast and slow stage.The adsorption experiments showed that non-modified quartz sand had almost no ability to remove phosphorus. After surface modification with zinc oxide, there is a greater change on phosphate removal capacity, and its static adsorption capacity of0.714mg P/g. Initial phosphorus solution pH values had a great effect on phosphorus removal and in the acid condition ZnO modified quartz sand had a higher removal efficiency. The recycling experiments showed that ZnO modified quartz sand could achieve removal efficiency of60%with recyling times of three. The dynamic removal experiments showed that column test had two stages based on the phosphorus concentrations of fitrate:phosphorus removal in high efficiency and phosphorus removal in low efficiency.