The effect of alkalinity of water on the phosphorus removal by the crystallization method were studied using the batch and column systems. Contact time in the batch experiments were from 1 to 25 hours, and length of the column experiments were for 68 days. Seed materials used for the experiments were prepared from phosphate rock.
According to the results of the batch experiments, it was found that the rate of phosphorus removal decreased as the alkalinity of water increased. In case of the column experiments efficiency of phosphorus removal was largely affected by the operating conditions such as pH and calcium ion concentration. The seed materials used for the column experiments were analyzed by X-ray powder diffraction method. It was found that the amount of calcite crystal in the seed materials was varied by the alkalinity and pH of water.

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