Desorption of dye from activated carbon beds: effects of temperature, pH, and alcohol

• Published in: Water research (Oxford) Vol. 35; no. 17; pp. 4159 - 4165
• Main Authors: Chern, Jia-Ming, Wu, Chia-Yuan
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2001; Elsevier Science
• Subjects: activated carbon; Adsorption; adsorption isotherm; Alcohols - chemistry; Applied sciences; Charcoal - chemistry; Coloring Agents - chemistry; desorption curve; dye wastewater; Exact sciences and technology; Hydrogen-Ion Concentration; Industrial wastewaters; Models, Chemical; Pollution; Temperature; Wastewaters; Water Purification - methods; Water treatment and pollution; wave theory; dye wastewater; activated carbon; desorption curve; adsorption isotherm; wave theory; Adsorption; Organic dye; Industrial waste water; Activated carbon; Adsorption isotherm; Temperature effect; pH; Desorption; Physicochemical purification; Waste water purification; Experimental study; Textile industry
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/S0043-1354(01)00127-0

The adsorption isotherms of yellow and red dye solutions onto granular activated carbon at varying solution pHs (2–8), temperatures (15–50°C), and alcohol concentrations (0–20%) were experimentally determined by batch tests and the Tóth model was found to best fit the adsorption isotherm data for varying solution pHs, temperatures, and alcohol concentrations. The maximum adsorption capacity was found to decrease with increasing solution pH and alcohol concentration and could be predicted by the correlation equations obtained in this study. A correlation equation was also obtained to account for the effects of solution temperature on the adsorption equilibrium constant. The 25°C water was found to be a very poor regenerant for the carbon bed presaturated with the yellow dye compared with 20% alcohol solution. A simple equation was derived, based on non-linear wave propagation theory, to predict the desorption curves of activated carbon bed. Given presaturation concentration, bed density and void fraction, and adsorption isotherm, the wave propagation theory predicted the desorption curves quite satisfactorily.