Basic dye (methylene blue) removal from simulated wastewater by adsorption sawdust: a timber using Indian Rosewood industry waste

Dyes are usually present in trace quantities in the treated effluents of many industries. The effectiveness of adsorption for dye removal from wastewaters has made it an ideal alternative to other expensive treatment methods. This study investigates the potential use of Indian Rosewood (Dalbergia sissoo) sawdust, pretreated with formaldehyde and sulphuric acid, for the removal of methylene blue dye from simulated wastewater. The effects of different system variables, viz., adsorbent dosage, initial dye concentration, pH and contact time were studied. The results showed that as the amount of the adsorbent was increased, the percentage of dye removal increased accordingly. Higher adsorption percentages were observed at lower concentrations of methylene blue. Optimum pH value for dye adsorption was determined as 7.0 for both the adsorbents. Maximum dye was sequestered within 30 min after the beginning for every experiment. The adsorption of methylene blue followed a first order rate equation and fit the Lagergren equation well. Similar experiments were carried out with commercially available activated carbon to compare the results. Sulphuric acid treated sawdust or formaldehyde treated sawdust of Indian Rosewood can be attractive options for dye removal from dilute industrial effluents. (C) 2004 Elsevier Ltd. All rights reserved.