Removal of rhodamine dye from aqueous solution using Gulmohar tree fruit activated carbon

摘要

Rhodamine B (Basic Dye) was selected as the test dye for the evaluation of the adsorption capacity of activated carbon prepared from the fruits of Gulmohar tree. Batch-mode adsorption studies were carried out by varying different parameters such as agitation time, initial dye concentration, carbon dose, particle size and pH. Desorption studies mainly carried out to elucidate the mechanism of adsorption. The time required to attain equilibrium was found to be within 75 min for all the concentrations studied (10 to 40 mg/L). The adsorption followed both Langmuir and Freundlich isotherms. The adsorption capacity was found to be 31.847 mg/g of Gulmohar tree Fruit Carbon (GTFC)at an initial pH of 5+0.2 at room temperature (30 ±2°C) for the particle size of 125-250 urn. The complete removal of the dye from 20 and 30mg/L aqueous solution was possible with 6 and 10g of the activated carbon respectively. The percent removal was increased with decrease in the particle size of the adsorbent. The influence of pH on dye removal was insignificant and a portion of the dye from the carbon was recovered in basic medium.