SIMULTANEOUS RECOVERY OF PHOSPHORUS AND POTASSIUM FROM LIVESTOCK WASTEWATER BY AN ELECTROLYTIC CRYSTALLIZATION METHOD

Abstract

 An electrolytic crystallization reactor was installed at a small-scale pig farm. Using the effluent from the activated sludge process treating the actual livestock wastewater, the continuous pilot-scale experiments were carried out to evaluate nutrients removal efficiencies of the electrolyzer. It could be confirmed from the experiments that crystalline substance was generated around the cathode through the electrolysis and thereby effluent concentrations of nutritive salts were decreased. The nutrient removal rate was changed depending on the influent load of nutritive salts, applied electric current and interval of polarity reversal. The crystalline substance recovered contained phosphorus, potassium, magnesium and calcium in large quantities. The results suggested that hydroxyapatite (HAp) and magnesium phosphate (MP) might be simultaneously formed through the electrolysis.