Adsorption of synthetic dyed wastewater using activated carbon from rice husk

The purpose of this study was to remove dyes from synthetic dyed wastewater using activated carbon derived from rice husk. The initial dye concentration was 45 mg/L. The batch adsorption worked best in an acidic medium of pH 2, adsorbent dosage of 13 g/L and agitation speed of 100 rpm with maximum dye removal of 80% after 10 min. The maximum adsorption capacity of the absorbent was found to be 2.0 mg/g with a final dye concentration of 10.8 mg/L. The adsorption was found to be a non-spontaneous, endothermic chemisorption process with less disorder which best fitted the Temkin model and followed pseudo-second order. For column adsorption, the highest qo corresponds to 12.8 mg/g and the maximum dye removal was above 99.5%. Some of the experimental deductions were confirmed by gas-phase computations [B3LYP/6-31G(d)].