Characterization of both anionic and cationic surfactant-modified natural zeolite and its application for removal of metal-ions from aqueous medium

Abstract

Natural zeolite from Nor Koghb deposit (Armenia) was modified by anionic surfactant sodium dodecyl sulfate and cationic surfactant cetyltrimethylammonium bromide; and the modified samples were used for the removal of metal-ions from aqueous medium. The surface and textural characteristics of both natural and modified zeolites were studied by nitrogen adsorption/desorption isotherms and FTIR methods. The specific surface area, microporous surface area, volume of macro- and microporous both for natural and surfactant-modified zeolites were determined. It was shown that the surfactant-modified zeolites are effective adsorbents for the removal of metal-ions from aqueous medium. It was established that the optimal conditions of Co2+, Ni2+, Fe2+, Cu2+, Zn2+, Mn2+, and Pb2+ metal-ions adsorption are as follows: mMe2+=50 mg/l, Vsolution=500 ml, mSMZ=0.7 g, pH=6.5, T=298 K. Under these conditions, it is possible to remove the 88.27% Co2+, 87.54% Fe2+, 81.37% Ni2+, 76.49% Cu2+, 58.79% Zn2+, 29.32% Mn 2+, 23.49% Pb2+ and 75% Cr(VI) from single-component system. In the multi-component system, the effectiveness of metal-ions removal is lower. From presented study, it is allowed that due to the low cost, industrial quantities availability of the natural Armenian zeolite and the high efficiency of their surfactant-modified samples as metal-ions removal sorbents, as well as easy and non-valuable process of modification, they can find wide application as effective adsorbents for purification of wastewaters.