Removal of Congo Red Dye from Industrial Wastewater by Untreated Sawdust

Abstract

Dyes have widespread applications and exist in the effluents of various manufacturing and processing units; therefore, its discharge has a severe environmental impact. However, the complex aromatic molecular structures of dyes make them very stable, and as a result, more difficult to biodegrade. The objective of the present study is to explore the feasibility of using untreated sawdust in the removal of Congo Red dye from industrial wastewater. The adsorption study was carried out using different particle sizes of adsorbent (90 µm, 144 µm and 355 µm), different pH values ranging from 5.0 to 11.0 along with different adsorbent amounts from 2.0 to 8.0 g. Flow rate was also varied in the range of 0.3 to 0.7 mL/min. Optimization of volume required for saturation of untreated sawdust was investigated. Adsorption method showed the optimum removal of Congo Red dye under the following conditions: constant initial concentration of 10 mg/L dye solution, volume of 200.0 mL, flow rate 0.3 mL/min, adsorbent amount 8.0 g and particle size of 90 µm. This effective removal method may provide a promising solution of removal of Congo Red dyes from textile wastewater in Bangladesh as well as other countries of the world.