Removal of diazo and triphenylmethane dyes from aqueous solutions through an adsorption process

✍ Scribed by M Sankar; G Sekaran; S Sadulla; T Ramasami

• Publisher: Wiley (John Wiley & Sons)
• Year: 1999
• Tongue: English
• Weight: 195 KB
• Volume: 74
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(199904)74:4<337::aid-jctb39>3.0.co;2-u

✦ Synopsis

Direct Red 31, Acid Black 1 and Acid Green 16 belonging to diazo and triphenylmethane classiücation of dye chemicals are widely used during the manufacture of leather. The spent dyestuþ s in wastewater escape biological treatment owing to their poor biodegradability. An adsorption procedure was used in this study for the removal of dyes from aqueous solution using Rice Bran-based Activated Carbon (RBAC). The molecular weight of the dye chemicals, the mass of RBAC and the diameter of RBAC particle had positive eþ ects on the rate of adsorption. Initial concentration of dye chemicals, pH of the dye solution and temperature of adsorption showed a negative impact on adsorption. The enthalpies of adsorption for Direct Red 31, Acid Black 1 and Acid Green 16 were Ô32.1, Ô23.4 and Ô21.7 KJ mol-1 respectively, indicating the adsorption was an exothermic physical process. The entropies of adsorption for Direct Red 31, Acid Black 1 and Acid Green 16 were Ô96.94, Ô59.92 and Ô26.96 J K-1 mol-1 respectively, suggesting that RBAC favours the adsorption process.