Effect of the coexistence of SO32- and PO43- on the adsorption performance of zeolite-loaded FeOOH@ZnO for S2.

ABSTRACT

The present study deals with the synthesis of zeolite-loaded FeOOH@ZnO by hydrothermal method and investigates the effects of coexisting SO32- and PO43- ions in the aqueous solution on the adsorption performance for S2-. The results showed that the HNO3-modified zeolite loaded with FeOOH@ZnO (FeOOH@ZnO/HZ) resulted in a maximum S2- removal rate of ≈98%. The adsorbent's performance on removing S2- was significantly enhanced, compared with NaOH and ZnCl2-modified zeolites loaded with FeOOH@ZnO, and the adsorption was proved to be a heat-absorbing process. When SO32- and PO43- coexisted with S2-, SO32- and PO43- had a significant influence on the adsorption properties of FeOOH@ZnO/HZ. When three ions of S2-, SO32- and PO43- were present simultaneously, the adsorption performance of FeOOH@ZnO/HZ on S2- was further, and the removal rate dropped to about 80%. Moreover, FeOOH@ZnO/HZ also adsorbed PO43- and SO32- in the system containing multiple ions, but the adsorption rates of PO43- and SO32- were much lower than S2-. This indicated that the adsorption of S2- in the presence of FeOOH@ZnO/HZ dominates under competitive conditions.