Muedi, Khathutshelo LilithBrink, Hendrik GideonMasindi, V.Maree, J.P.2022-11-012021-07Muedi, K.L., Brink, H.G., Masindi, V. &, Maree, J.P. 2021, 'Effective removal of arsenate from wastewater using aluminium enriched ferric oxide-hydroxide recovered from authentic acid mine drainage', Journal of Hazardous Materials, vol. 414, art. 125491, pp. 1-18, doi : 10.1016/j.jhazmat.2021.125491.0304-3894 (print)1873-3336 (online)10.1016/j.jhazmat.2021.125491https://repository.up.ac.za/handle/2263/88031This study explored an eco-friendly approach for the synthesis of novel aluminium enriched ferric oxide-hydroxide (Fe/AlO(OH)) from authentic acid mine drainage (AMD). The synthesized Fe/AlO(OH) was subsequently tested for arsenate removal capabilities. Fe/AlO(OH) was synthesized from bona fide AMD via selective precipitation, thermal activation, and vibratory ball milling. One-factor-at-a-time (OFAAT) method was used to optimize operational parameters, which include adsorbent dosage, concentration, pH, agitation time, and temperature. Optimized conditions were observed to be 150 ppm of As(V), Solid: Liquid ratio – 1 g: 250 mL, contact time of 60 min, and ambient temperature and pH. Limited temperature and pH effects on adsorption were observed. Equilibrium data fits using Langmuir-, Freundlich-, Two surface Langmuir-, Dubinin-Radushkevich-, and Dubinin-Astokov isotherm models showed highly favorable adsorption conditions, the highest known maximum adsorption capacity for As(V) of 102–129 mg g−1, and coupled physisorption/diffusion limited adsorption. Thermodynamic analysis showed positive Gibbs free energy (ΔG°), negative enthalpy change (ΔH°), and positive entropy change (ΔS°) – likely a result of an inner sphere complexation of the As(V) with the Fe/Al surface. Considering the obtained results, valorization of AMD for the synthesis of Fe/AlO(OH) was viable and effective. This initiative could potentially minimize the footprints of AMD and arsenic pollution.en© 2021 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Journal of Hazardous Materials. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Journal of Hazardous Materials, vol. 414, art. 125491, pp. 1-18, 2021. doi : 10.1016/j.jhazmat.2021.125491.Acid mine drainage (AMD)ArsenicAdsorptionAluminiumFerric oxide-hydroxide (Fe/AlO(OH)One-factor-at-a-time (OFAAT)Postprint Article