Efficiency of Meretrix Lamarckii activated carbon in malachite green dye removal

Dyestuff manufacturing and consuming industry has led to water pollution through their discharge of untreated wastewater. Presence of dyes in water bodies may cause carcinogenic, mutagenic and caused harm to the entire aquatic ecosystem. This research has carried out to examine the adsorption efficiency of activated carbons derived from waste Meretrix lamarckii (M. lamarckii) shells towards Malachite Green (MG) dye removal. Activation with hydrochloric acid (HCl) and potassium hydroxide (KOH) were used for the conversion of seashells into AC 1 and AC 2 respectively. Following that, batch adsorption studies were carried out at 30°C by using AC 1 and AC 2 to study the effect of contact time, pH, initial concentration of adsorbate and adsorbent dosage on dye removal percentage. The optimized contact time for AC 1 was 210 minutes, with best performance in pH 10 aqueous medium, 10 mg/L initial concentration of MG and optimum dosage of 1.0 g. Whereas for AC 2, the optimized contact time was shorter than AC 1, which was only 90 minutes to attain equilibrium state. The optimized pH and initial concentration of adsorbate was the same as AC 1. While optimized adsorbent dosage for AC 2 was lower than that of AC 1, which was 0.8 g. Based on the results obtained, AC 2 was found to be more effective in MG dye removal than AC 1. High efficiency of AC 2 was due to the presence of alkyl halide group and its larger total surface area. From the study, it can be concluded that M. lamarckii activated carbons possess high adsorption efficiency and potentially to become a new introduce adsorbent in wastewater treatment technology.