Abstract
In this study, carrot juice pulp (CJP) and pomegranate peel (PP) biomass wastes were used as alternative pre-cursors for producing high surface area activated carbon (referred to as CJPPPAC) using microwave radiation assisted with ZnCl2 activation. The CJPPPAC has a large surface area (SA = 1202.2 m2/g), according to the Brunauer-Emmett-Teller analysis, and a mesoporous structure (average pore diameter of 3.0 nm). The adsorption characteristics of CJPPPAC were studied for the removal of a model of cationic dye (crystal violet; CV). The numerical desirability function of the Box-Behnken design (BBD) was used to optimize important adsorption variables (A: CJPPPAC dose (0.02-0.08 g); B: pH (4-10); C: time (2-6); and D: initial CV concentration (20-80 mg/L). The dye adsorption kinetics profile followed a pseudo-second-order (PSO) model, whilst the equilibrium adsorption was described by the Freundlich model. The maximum adsorption capacity (qmax) of CJPPPAC for the CV dye was identified to be 211.8 mg/g. The adsorption mechanism of CV dye onto the CJPPPAC surface occurs by a variety of mechanisms including electrostatic forces, pore diffusion, 7C-7C stacking, and H-bonding. This work illustrates the applicability of CJP and PP as biomass precursors for the efficient production of CJPPPAC and its utility for wastewater treatment.