Nutrients Removal from Swine Wastewater by Natural Na-type Mordenite

Taking Na-type mordenite as the experimental material, batch experiments were carried out to investigate the influence of mordenite dosage, reaction time, pH, Ca²⁺ concentration and Mg²⁺ concentration on simultaneous removals of nitrogen and phosphorus from actual swine wastewater. It showed that under the conditions of mordenite dosage of 300 mg/L, pH of 8.0~9.0 and adsorption duration of 4 h, the removal efficiencies of high-concentration ammonia and phosphate by mordenite could reach 92% and 86%, respectively. With the increase of pH, the removal efficiency of ammonia and phosphate increased firstly and then decreased. However, the removal efficiency of ammonia reached the highest value around 90% at pH of 8.0, with phosphorus removal efficiency reaching the highest value of 85% at pH of 9.0. The effect of Ca²⁺ concentration on ammonia removal was not obvious, but was significant for phosphate removal. At P: Ca molar ratio of 1:6 and pH of 9.0, the removal efficiency of phosphate could reach 88%. The effect of Mg²⁺ concentration was significant for ammonia and phosphate removal. At P:Mg molar ratio of 1:4 and pH of 10.0, the removal efficiencies of ammonia and phosphate could reach 93% and 91%, respectively.