PREPARATION OF Ca-P ZEOLITE FROM PAPER SLUDGE ASH VIA ACID LEACHING FOR SIMLTANEOUS REMOVAL OF NH4+ and PO43-

摘要

This study aimed to investigate the preparation of Ca-P zeolites from paper sludge ash (PSA) via acid leaching in order to remove both of NH4+and PO43-for water purification. PSA typically has a low Si abundance and significant Ca content, due to the presence of calcite fillers. Acid leaching with HCl was used to reduce the Ca content so that zeolite-P (Na-P) zeolitic product with a high cation exchange capacity (CEC) could be synthesized through reaction with 2.5 M NaOH solution at 80 ℃, and Ca-P zeolitic products were prepared by ion exchange treatment with extracted Ca solution via acid leaching. The product with high CEC capacity including Na-P can be synthesized from the ash leached with 3 M HCl solution, and high Ca content can be extracted into the leachant via acid leaching. By ion exchange with the solution, which is obtained by neutralization of leachant with NaOH, Ca-P zeolites could be prepared and can remove NH4+and PO43-from aqueous solution, simultaneously. The product with simultaneous removal ability of NH4+and PO43-from aqueous solution was prepared from PSA via acid leaching process, which is preferable for application in water purification.