Optimization of preparation conditions for mangosteen peel-based activated carbons for the removal of Remazol Brilliant Blue R using response surface methodology

This study investigates the optimal conditions for preparation of activated carbons from mangosteen peel (MP) for removal of Remazol Brilliant Blue R (RBBR) reactive dye from aqueous solution. The MP activated carbon was prepared using physiochemical activation method which consisted of potassium hydroxide (KOH) treatment and carbon dioxide (CO2) gasification. Central composite design (CCD) was used to determine the effects of the three preparation variables; CO2 activation temperature, CO2 activation time and KOH impregnation ratio (IR) on RBBR percentage removal and activated carbon yield. Based on the CCD, a quadratic model and a two-factor interaction (2FI) model were respectively developed for RBBR percentage removal and carbon yield. The significant factors on each experimental design response were identified from the analysis of variance (ANOVA). The optimum conditions for MP activated carbon preparation were obtained by using activation temperature of 828 °C, activation time of 1 h and IR of 3.0, which resulted in 80.35% of RBBR removal and 20.76% of activated carbon yield.