Preparation and Utilization of Corncob Activated Carbon for Dyes Removal from Aqueous Solutions: Batch and Continuous Study

Abstract

Commercial activated carbon and produced corncob activated carbon were used for the adsorption of methylene blue dye from aqueous solution using batch and continuous processes. Batch processes were conducted to study the effects of solution pH, contact time, adsorbent dose, agitation speed and initial dye concentration. The optimum values for methylene blue dye adsorption were: solution pHs of 6 and 7, contact times of 8 and 5 hr., adsorbent dosages of 1.5, and 0.5 gm, agitation speeds of 200 and 250 rpm and initial dye concentration of 50 mg/l calculated by commercial activated carbon and corncob activated carbon respectively. Two isotherm models, Freundlich and Langmuir fitted with the experimental data found from batch processes, the Langmuir model fitted well than the Freundlich, with maximum adsorption capacities of 16.21 and 30.95 mg/g and R2 of 0.952 and 0.992 predicted by commercial activated carbon and corncob activated carbon respectively. Radial and vertical flow regime reactors were conducted in column tests for the two adsorbent materials at different three flow rates (0.2, 0.3 and 0.4 L/min) and initial dye concentrations 15 mg/l, the same volume of (775 ml) from adsorbent materials used for both radial and vertical reactors to make a comparison between the capacity of the adsorbent materials each with another and between the performance of radial and vertical flow regime reactors configurations on breakthrough curves behavior. Radial flow regime reactor showed good results in comparison with vertical flow regime reactor.