Optimization of process variables by response surfacemethodology for malachite green dye removal using lime peelactivated carbon

This study investigates the adsorptive removalof malachite green (MG) dye from aqueous solutions usingchemically modified lime-peel-based activated carbon(LPAC). The adsorbent prepared was characterized usingFTIR, SEM, Proximate analysis and BET techniques, re-spectively. Central composite design (CCD) in responsesurface methodology (RSM) was used to optimize the ad-sorption process. The effects of three variables: activationtemperature, activation time and chemical impregnationratio (IR) using KOH and their effects on percentage of dyeremoval and LPAC yield were investigated. Based on CCDdesign, quadratic models and two factor interactions (2FI)were developed correlating the adsorption variables to thetwo responses. Analysis of variance (ANOVA) was used tojudge the adequacy of the model. The optimum conditionsof MG dye removal using LPAC are: activation tem-perature (796°C), activation time (1.0 h) and impregnationratio (2.6), respectively. The percentage of MG dye re-moval obtained was 94.68 % resulting in 17.88 % LPACyield. The percentage of error between predicted and ex-perimental results for the removal of MG dye is 0.4 %.Model prediction was in good agreement with ex-perimental results and LPAC was found to be effective inremoving MG dye from aqueous solutio