Improvement in adsorption of Hg2+ from aqueous media using sodium-type fine zeolite grains.

Abstract

To increase the adsorption capability of Hg2+ from aqueous media, we prepared sodium-type fine zeolite grains with various particle sizes (denoted as ZE1, ZE2 and ZE3). The particle sizes of ZE1, ZE2 and ZE3 were 16.363 ± 0.365, 1.454 ± 0.357 and 0.607 ± 0.377 μm, respectively. Moreover, the CEC, specific surface area and pore volume were in the order ZE1 (42 mmol/g and 23.5 m2/g) < ZE2 (72 mmol/g and 67.1 m2/g) < ZE3 (135 mmol/g and 176.6 m2/g). Subsequently, the Hg2+ adsorption capability was investigated. The performance of tested agents on Hg2+ adsorbed was in the order ZE1 (5.0 mg/g) < ZE2 (9.4 mg/g) < ZE3 (20.2 mg/g). It was concluded that fine crystalline zeolite was important in enhancing the adsorption capability of Hg2+. In addition, the mechanism of adsorption of Hg2+ on the ZE samples was evaluated. Our results suggested that Hg2+ was exchanged with sodium ions in the interlayers of ZE samples with correlation coefficients of 0.966-0.979. Our findings revealed that these ZE samples constitute potential agents for the adsorption of Hg2+ from aqueous media.