Chemically Modified Biochar Produced from Conocarpus Wastes: An Efficient Sorbent for Fe(II) Removal from Acidic Aqueous Solutions.

Fe(II) removal from acidic aqueous solutions using Conocarpus sp. biochar or chemically modified biochar prepared by synthesizing Mg(OH)2 on biochar surface as well as their comparison with zeolite sorbent (natural clinoptilolite) was investigated. Batch experiments were conducted as a function of initial pH of 2-5, contact time of 5-180 minutes and initial concentration of 10-200 mg l-1 (0.18-3.58 mmol l-1). The sorption data indicated that the pseudo-second-order kinetic model was the best model to simulate adsorption of Fe(II) onto the all sorbents and could generally be described by the Freundlich model. The higher sorption capacities for Fe(II) ions were generally pronounced for chemically modified biochar (84.6-99.8%) followed by biochar (38.3-97.6%) than those that were achieved by zeolite (12.3-95.5%). Thus, remediating acidic wastewater contaminated with Fe(II) might be possible using Conocarpus biochar, especially the chemically modified biochar. [ABSTRACT FROM AUTHOR]