No abstract

The use of low-cost, locally available, highly efficiencient and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from the Annona squmosa seed for the removal of methyl red (MR) dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH and contact time were investigated and optimal experimental conditions were ascertained. The results showed that as the amount of the adsorbent increased, the percentage of dye removal increased accordingly. Optimum pH value for dye adsorption was 4.0. Maximum dye was sequestered within 50 min of the start of every experiment. The adsorption of methyl red followed the pseudo-second-order rate equation and fits the Langmuir, Freundlich, Dubinin-Radushekevich (D-R) and Tempkin equations well. The maximum removal of MR was obtained at pH 4 as 82.81% for adsorbent dose of 0.2 g/ 50 mL and 25 mg L −1 initial dye concentration at room temperature. Furthermore, adsorption kinetics of MR was studied and the rate of adsorption was found to conform to pseudo-second-order kinetics with a good correlation (R 2 > 0.99) with intraparticle diffusion as one of the rate determining steps. Activated carbon developed from the Annona squmosa seed can be an attractive option for dye removal from diluted industrial effluents since test reaction made on simulated dyeing wastewater showed better removal percentage of MR.

No abstract

Carbon prepared from the epicarp of Ricinus communis was used to remove a textile dye (methylene blue (MB)) from an aqueous solution by adsorption technique under varying conditions of agitation time, dye concentration, adsorbent dose and pH. Adsorption depended on solution pH, dye concentration, carbon concentration and contact time. Adsorption followed both Langmuir and Freundlich isotherm models. The adsorption capacity was found to be 62.5 mg/g at a neutral pH of 7 for the adsorbent size of 125-250 µm at room temperature (32±2• C). The kinetics of adsorption of MB obeys Pseudo-first order. The results in this study indicated that activated carbon from Ricinus communis was an attractive candidate for removing cationic dyes from the dye wastewater.

No abstract