Optimized preparation for bimodal porous carbon from lentil processing waste by microwave-assisted K 2 CO 3 activation: Spectroscopic characterization and dye decolorization activity

This paper describes lab-scale experiments for producing optimal activated carbon (LWAC)with bimodal porous (mixed micro-mesoporous)texture under optimized conditions from lentil processing waste (LW)by microwave-assisted K 2 CO 3 activation. The influences of various operating parameters were evaluated including impregnation ratio (IR), carbonization temperature (CT)and carbonization time (Ct). The BET surface area (S BET )and total pore volume (V T )were chosen as main criteria in optimization. The optimized parameters were IR ratio of 3:1, CT of 800 °C and Ct of 1 h. The physicochemical properties of LW and LWAC were identified with diverse analytical techniques. LWAC possessed high S BET of 1875 m 2 /g and large V T of 0.995 cm 3 /g. The LWAC was then tested for its feasibility as cationic (Methylene blue (MB))and anionic (Methyl orange (MO))dyes adsorbent. It was found that LWAC has an adsorption capacity of 625 mg/g for MB and 476 mg/g for MO at 30 °C