“ OPTIMISATION OF SULFURIC ACID CONCENTRATION FOR ENHANCED FE2+ ION REMOVAL USING ACTIVATED CHARCOAL FROM BOILED PEANUT SHELLS: CHARACTERISATION AND PERFORMANCE EVALUATION ” (2024) Lingkar: Journal of Environmental Engineering, 5(1), pp. 10–18. Available at: https://journal.ar-raniry.ac.id/index.php/lingkar/article/view/5080 (Accessed: 18 October 2026).