Electrochemical Removal of Phosphate Ions from Treated Wastewater

The objective of this work was to investigate electrochemical removal of phosphate from secondary treatment effluent containing calcium and magnesium hardness. Phosphate and hardness removal were carried out using a recently developed technique based on an electrochemical cation exchange membrane system (ECM system). The ECM system overcomes major drawbacks of the current electrochemical technology, notably high electrode area requirements. The parameters investigated were the effects of current density and pH on the phosphate precipitation rate and on the fractional phosphate removal. The effect of presence or absence of phosphate ion on the coprecipitation of calcium carbonate and magnesium hydroxide was also studied. Results indicate the feasibility of viable electrochemical phosphate removal by the convenient ECM technique.