Optimization of activation process of nanoclay for removal of Reactive Navy Blue SP- BR dye using centeral composite design experiment

Activated and modified nanoclay is widely applied as adsorbent for removal of organic contaminants in soil, water and air [1]. In this work, Montmorillonite K10 nanoclay was activated by sulfuric acid and modified by cetyltrimethylammonium bromide (CTAB). The adsorption of Reactive Navy Blue SP-BR on prepared nanoclay was investigated through a batch process. In the present study central composite design, which is a widely used form of Response Surface Methodology (RSM), was employed for optimization of activation process. Also, the effect of the activation parameters (acid concentration (mol L-1), temperature (°C) and contact time (h)) was investigated. Experimental data were analyzed using Minitab 15 software. Predicted values of decolorization efficiency were found to be in good agreement with experimental values (R2= 0.9688 and Adj–R2= 0.9408, respectively). Optimization results showed that maximum decolorization efficiency was achieved at the optimum conditions of activation: temperature 50 °C, acid concentration 3.5 mol L-1 and contact time 2.5 h. The activated and modified nanoclays were analyzed by Fourier Transform Infrared (FT−IR) spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques.