Response Surface Modeling and Optimization of Remazol Brilliant Blue Reactive Dye Removal Using Periwinkle Shell-Based Activated Carbon

This work investigates both batch and optimization studies of adsorption of Remazol Brilliant Blue Reactive (RBBR) dye onto activated carbon prepared from periwinkle shells (PSAC). The effects of three preparation variables: CO2 activation temperature, CO2 activation time, and KOH: char impregnation ratio (IR) were studied using Response Surface Modeling (RSM). Based on the central composite design (CCD), a quadratic model and two-factor interaction models (2FI) were developed to correlate the three preparation variables to the two responses: RBBR dye removal and PSAC yield. The optimum conditions for preparing PSAC for adsorption of RBBR dye were found as follows: CO2 activation temperature of 811 degrees C, CO2 activation time of 1.7 h and IR of 2.95, which resulted in 82.76% of RBBR dye removal and 35.83% of PSAC yield. Experimental results obtained agreed satisfactorily well with the model predictions. The activated carbon prepared under optimum conditions was mesoporous with BET surface area of 1894 m(2)/g, total pore volume of 1.107 cm(3)/g and average pore diameter of 2.32 nm. The surface morphology and functional groups of PSAC were respectively determined from the scanning electron microscopy (SEM) and Fourier transform infrared analysis (FTIR).