Activated Carbon as an Adsorbent: A Review

Activated carbon is highly porous with a large surface area for activity, thus making it highly adsorption efficient, and is usually derived from waste products. The proximate and ultimate analysis of agricultural waste material and chemical compositions such as hemicelluloses, cellulose, and lignin contents were also discussed. The authors reviewed chemical activators such as alkali hydroxides, KOH, phosphoric acid, zinc chloride, potassium carbonate, and NaOH used to produce activated carbon. A detailed explanation of the characterization techniques (SEM, FTIR, EDAX, BET, XRD etc.) for precursors and activated carbons are discussed. The effect of various parameters on adsorption efficiency of activated carbon is discussed. Wastewater containing different toxic dye contaminants causes serious environmental problems. Removal of various pollutants (SO2, NO2, H2S, CO2 etc.) using activated carbon were reviewed. In addition, the equilibrium adsorption data were fitted to Isotherm models for the determination of constants correlated to the adsorption phenomena was reviewed.