Preparation of raw Oyster Shell for removal of Toluidine Blue Dye in aqueous solution

Dye in the effluent is one of the global pollution problems due to its adverse effect on various forms of life. It is evident from previous researchers about the low-cost agricultural waste as an adsorbents have capabilities in removal of dye from an aqueous solution. In this study, the adsorption of Toluidine Blue (TB) dye from aqueous solution using raw oyster shell was investigated. Adsorption using raw oyster shell is environmental friendly, low cost and effective adsorbents in wastewater treatment. Adsorption studies were carried out to investigate the effect of various adsorption parameters which are adsorbent size, adsorbent dosage, initial dye concentration, contact time and pH. The optimum condition for adsorption of TB dye were obtained at 45 µm of adsorbent size with 3.5 g of adsorbent dosage and 30 mg/L initial dye concentration in 2 hour time at pH 10. The highest percentage of TB removal was 99.24% and the experimental data obtained were well fitted on Langmuir isotherm model. The maximum adsorption capacity was up to 1.2015 mg/g at R2 = 1 in which indicated that monolayer adsorption mechanism. Thus, this proved that raw oyster shells have the potential for TB dye removal from aqueous solution.