Study on simultaneous degradation of nitrogen and phosphorus in wastewater from sludge dewatering removal by mixing sodium and lanthanum modified zeolite

Abstract

This paper studied the adsorption of nitrogen and phosphorus in wastewater from sludge dewatering by sodium and lanthanum modified zeolite. Under the condition of initial concentration of 50mg/L, the dosage of 7.5g/L and reaction time of 3h, the removal rate of ammonium reached 92% by sodium zeolite; while the removal rate of phosphate reached 99% by lanthanum zeolite under the condition of initial concentration of phosphorus 60mg/L, the dosage of 10g/L and reaction time of 12h. Two kinds of modified zeolite were mixed to synchronously remove nitrogen and phosphorus from wastewater from sludge dewatering. The results showed that the removal of phosphate by lanthanum zeolite was motion influenced by the concentration of ammonium in the solution, and the existence of lanthanum zeolite was useful to promote the removal of ammonium. Otherwise, sodium zeolite did not have the ability to adsorb phosphate, and the capacity of ammonium adsorption decreased with the increase of phosphate concentration in the solution. When the mass mixing ratio of sodium zeolite and lanthanum zeolite was 4:6, the removal rates of ammonia nitrogen and phosphorus reached 89.6% and 97.5% respectively.