Arsenic Adsorption on Bauxite Mineral Using Batch Equilibrium Test

Abstract

Problem statement: Study suggested a solution to remove arsenic contamination from contaminated water. Approach: Bauxite, which is a mineral, was proposed as natural remediation material used in this study. Bauxite was collected from Johor mining company in Teluk Ramunia, Johor Bharu, Malaysia. Batch equilibrium test was performed in accordance to different initial concentrations, shaking time and different initial pH values. Results: Results showed that mineral bauxite has high Cation Exchange Capacity (CEC) and Specific Surface Area (SSA), with the values range from 23.9-32.6 meq/100 g and 18.5-22.09 m^₂ g^_-1, respectively. Sample of bauxite mineral is slightly acidic with pH values ranging from 5.06-5.35. Percentage of organic matter and carbonate content in bauxite are very low with the values of 3.78-4.57 and 2.435-2.5% respectively. For batch adsorption, results showed that bauxite has high adsorption capacity for arsenic and it can remove more than 99% of arsenic from contaminated water. The highest amount of arsenic adsorbed (q) was 4996.6 mg kg^_-1 in 500 ppm of arsenic concentration after 48 h of the test in pH 7.6. The lowest was 4554.7 mg kg^_-1 in 500 ppm of arsenic at 24 h of shaking time in pH 10. Conclusion: Results indicated that bauxite can be used as a natural material for the removal of arsenic from contaminated water.