Highly stable natural zeolite/montmorillonite hybrid microspheres with green preparation process for efficient adsorption of ammonia nitrogen in wastewater

Adsorption technology has attracted increasing attention for the remediation of ammonia nitrogen pollutions from landfill leachate. However, developing effective adsorbing materials with low cost, outstanding activities and long-term stabilities in the aqueous environment remains a significant challenge. Zeolite with high ability of cation exchange is significantly preferable for the removal of ammonia nitrogen. Herein, a novel polyvinyl alcohol (PVA) thin membrane modified natural zeolite and Na-montmorillonite (Na-Mt) hybrid microspheres (denoted as PVA-(zeolite/Na-Mt)) adsorbent is successfully synthesized by a facile granulation and impregnation method. The adsorption experiments reveal that the multicomponent PVA-(zeolite/Na-Mt) microspheres show higher removal efficiency (98.16%) for ammonia nitrogen within 40 h even at a wide pH (3.0-11.0) and temperature (10-30 degrees C) range. Meanwhile, the spent PVA-(zeolite/Na-Mt) microspheres with high stability in aqueous environment for more than 20 days originates from the modification of the PVA molecule and enhanced adsorption performance that is beneficial for practical applications in the wastewater remediation field.