Adsorption of dyes on multifunctionalized nano-silica KCC-1

Abstract

In the last few decades, the adsorption technique has attracted tremendous attention as a promising methodology for removing toxic dye pollutants from aquatic environments. Nanoporous adsorbents are one of the most popular adsorbents for dye removal. With comparing two different adsorbents, two important factors, namely adsorption capacity and adsorption time are of particular importance; the higher the adsorption capacity and the shorter the adsorption time, the better and more effective is the adsorption performance. In this paper, a multifunctionalized micro-mesoporous nano-silica KCC-1 (MF-KCC-1) adsorbent bearing 1-methylimidazolium/tetrasulfide/amine groups is synthesized by a simple post-functionalization of the pure KCC-1 for adsorption of acid orange II (AO) and acid fuchsin (AF) from water. In order to investigate the feasible mechanisms involved in the adsorption process, isotherm and kinetic studies were conducted. Among the various isotherm and kinetic models, the Langmuir isotherm and pseudo-first-order kinetic models showed the best agreement with the experimental data. The MF-KCC-1 showed a high adsorption capacity (676.7 and 621.3 mg g−1 for AO and AF) and a short adsorption time (20 min) under constant conditions (pH=3.0, adsorbent dose=0.100 g L–1, solution volume=30 mL, temperature=298 K, shaking speed=180 rpm). The results obtained in this study reveal the positive effect of surface functional groups on the adsorption performance of MF-KCC-1 as a promising nanoadsorbent.