KMnO₄ Modified Carbon Prepared from Waste of Pineapple Leaf Fiber Production Processing for Removal of Ferric Ion from Aqueous Solution

KMnO₄ modified carbon materials from waste of pineapple leaf fiber production processing were prepared and characterized. The effects of % weight of KMnO₄ (0-5 %wt) and carbonization temperature (500-700°C) were studied by SEM-EDS, XRD, FTIR and BET. The KMnO₄ modified waste carbon was used for Fe³⁺ removal from aqueous solutions. The effects of KMnO₄ modification, contact time, pH and loading were evaluated. The Langmuir isotherm and Freundlich isotherm were also used for evaluation of Fe³⁺ adsorption by KMnO₄ modified waste carbon. The results show that MnO₂ deposited on the surface of KMnO₄ modified waste carbon with some heterogeneity. The OH, CO and MnO groups are major functional groups on the surface of KMnO₄ modified carbon. The BET surface area and total pore volume of modified waste carbon is increased with increasing weight % of KMnO₄ and carbonization temperature, while the average pore size follows an inverse trend. The Fe³⁺ adsorption on modified waste carbon reaches equilibrium within 60 min. The amount of Fe³⁺ adsorbed on the modified waste carbon increases with increasing pH, reaches maximum at pH of about 4.7 and then sharply decreases at pH above 7. Both Langmuir and Freundlich isotherms were fitted for data a Fe³⁺ adsorption on modified waste carbon with 25.25 mg g^-1 as theoretical maximum adsorption capacity.