Adsorption and purification of orthophosphate by calcium peroxide CaO2

Calcium peroxideCaO2 can adsorb and purify all kinds of phosphates in water, especially orthophosphates. Under normal circumstances, organophosphates are hydrolyzed to orthophosphate under acidic conditions. Using calcium peroxide CaO2 as a phosphorus removal option for natural water bodies with low pollution not only has the advantages of low cost, high efficiency and no secondary pollution, but also the treated water bodies can reach the III specified in the surface water environmental quality standard (GB3838-2010). Therefore, we briefly describe the removal effect of calcium peroxide CaO2 on orthophosphate.

1. The adsorption rate of calcium peroxide CaO2 increases with the increase of phosphate concentration in solution, and the adsorption equilibrium can be reached after about 240 seconds. Why is this so? The reason is that first of all, the higher the concentration of the solution, the more phosphorus is available for adsorption by the substrate;

Secondly, the concentration difference between the solution and the liquid film on the outer surface of the matrix will increase with the increase of the concentration of the solution, which leads to the increase of the driving force of phosphorus migration to the matrix. Therefore, the increase of the concentration of the solution is conducive to the increase of the adsorption amount of phosphorus by the matrix.

2. According to relevant data and experiments, calcium peroxide CaO2 in water is a self-exothermic process, and the maximum adsorption capacity of orthophosphate in the exothermic process is 381.7 mg/g.

3, in the case of high concentration of co-existing anions, the phosphorus removal adsorption of calcium peroxide CaO2 may be reduced by 15%. Therefore, the coexistence of anions should be reduced as much as possible in the process of calcium peroxide CaO2 phosphorus removal. This may be due to the competitive adsorption of adsorption sites between co-existing anions and phosphate ions, and the number of adsorption sites on the adsorbent is certain, and the co-existing anions occupy a part of the adsorption sites, resulting in a decrease in the number of available phosphate ion adsorption sites, inhibiting the generation of Ca-P, and thus reducing the phosphorus removal effect of CaO2.

4, calcium peroxide CaO2 at pH =8 phosphorus removal effect reached the best value. pH affects the adsorption capacity of the adsorbent by changing the surface charge characteristics, the dissociation state of the solute and the dissolution equilibrium.

In recent years, many lakes in our country have presented different levels of eutrophication. The deterioration of water quality and destruction of ecological structure have affected the ecological stability of lakes. Therefore, it is necessary to control or reduce the phosphorus concentration in such water bodies and improve their water quality. Calcium hydroxyl phosphate, the dephosphorization product of calcium peroxide CaO2, is a very stable, non-toxic, harmless and recyclable compound. Calcium peroxide CaO2 particles or pressed into a faceted form, using natural energy to circulate the water and flow through the phosphorus removal material, to achieve durable and efficient phosphorus removal.