Removal of Colour from Textile Effluent by Adsorption Using Low Cost Adsorbents

Aims: The present study was aimed to investigate the adsorption capacity of Granular activated carbon (GAC) of coconut shell and coal ash for acidic dye.

Methodology: Acid orange 7 dye is used as an adsorbate for the present study. Operating parameters such as pH, effective dosage, and contact time were optimized by conducting batch experiment. Column studies were conducted in order to determine the saturation time by using column Break-through curve.

Results: Colour removal of about 94% and 85% were obtained at pH 6 for an adsorbent dosage of 1.5g /100ml of 50 mg/l and 100 mg/l dye concentration respectively for Granular activated carbon and Colour removal of about 80% and 75% were obtained at pH 6 for an adsorbent dosage of 1.5 g/100ml of 50 mg/l and 100 mg/l dye concentration respectively for Coal ash. GAC got saturated in 218 hours for 100 mg/l and coal ash got saturated in 96 hours for 100 mg/l respectively. Results obtained on industrial wastewater showed the results were in par with the synthetic sample.

Conclusion: From the batch and column studies it can be concluded that increase in adsorbent dosage increased the percentage removal of dyes and higher initial concentration resulted in shorter column saturation time respectively. Langmuir isotherm was found to be best fit for both the adsorbents.