Preparation of raw Oyster shell for removal of Coomassie Brilliant Blue R-250 Dye from aqueous solution

The removal of dye from textile wastewater effluent has become an important process nowadays. Industrial wastewater contains synthetic dyes which are hazardous to the environment, hence the dyes must be treated from water bodies. In this research, oyster shell was used as a raw adsorbent in the removal of Coomassie Brilliant Blue R-250 (CBB) dye by using the adsorption method in order to reduce the amount of waste oyster shells in waters and landfills which can cause pollution. Various parameters were investigated and optimised such as adsorbent size, adsorbent dosage, initial dye concentration, contact time and pH to study the potential of oyster shell as an adsorbent. The optimum value obtained was 75 µm of adsorbent size with 2.3 g of adsorbent dosage at 50 mg/L concentration of CBB dye. Optimum contact time of the dye adsorption was determined at 9 hours and the most effective condition for CBB dye removal was at pH 2. The removal efficiency was achieved at 99.64%. The experiment data were studied by using Langmuir adsorption isotherm and Freundlich adsorption isotherm. The best fit model obtained for the adsorption of CBB dye was Langmuir adsorption isotherm with R2 = 0.9995. Thus, this study was provided an economical and environment friendly dye removal process for wastewater treatment.