Nitrogen and Phosphate Removal by Zeolite-Rare Earth Adsorbents

Zeolite modified by rare earth lanthanum compounds would be an excellent water purification agent that can simultaneously remove both nitrogen and phosphate in aqueous solution. In the context, a novel adsorbent was prepared by loading lanthanum chloride on the zeolite, and the the optimal sorbent was produced at 0.5% La³⁺ and pH value 10 in the solution. Remove ammonia nitrogen and phosphate synchronously tests result showed that the new sorbent is very effective for ammonia nitrogen and phosphate removal, and the best adsorption capacity is 25 mg/g and 50 mg/g respectively. Feeding into 10 mg/L NH₄ ⁺-N and 5 mg/L H₂PO₄ ^- in wastewater, the removal ratio will be over 80% and 90% respectively, and dynamics for the process is accordance to Freundlich adsorption model. The result suggests that the novel rare earth adsorbent will provide a new way for the treatment of ammonia nitrogen and phosphate in wastewater.