Mesoporous silica functionalized with thiol groups and sulfonic acid groups for removal of organic and inorganic pollutants from wastewater

Abstract

Functionalization of mesoporous silica by covalent bonding of organic moieties on or within silica walls has received great attention in terms of the application of such materials in the field of adsorption. In this study, I have synthesized the mesoporous silica functionalized with thiol groups (MS-TG) by means of a simple method, involving co-condensation of TEOS and MPTMS in the presence of copolymers, P123. Also, mesoporous silica containing sulfonic acid groups (MS-SAG) was synthesized through the oxidation process of MS-TG. To compare their removal efficiency, the synthesized adsorbents were applied to remove three basic dyes and heavy metals from wastewater. Obviously, for all basic dyes, MS-SAG has a much larger adsorption capacity than conventional adsorbents including the MS-TG. And both adsorbents, MS-TG and MS-SAG, exhibited very good adsorption for lead and copper ions. The maximum adsorption capacities of MS-SAG for Pb(II)ion(71.43 mg/g) and Cu(II)ion(41.67 mg/g) were higher than those of MS-TG for Pb(II)ion(31.25 mg/g) and Cu(II)ion(35.71 mg/g), respectively. In addition, the influences of the pH, contact time, and competitive ions on the adsorption behavior were also discussed.