Effective removal of arsenate from wastewater using aluminium enriched ferric oxide-hydroxide recovered from authentic acid mine drainage

JOURNAL OF HAZARDOUS MATERIALS

卷:414

Article

Muedi, K. L.¹  Brink, H. G.¹  Masindi, V²  Maree, J. P.³ 

[1] Univ Pretoria, Fac Engn Built Environm & Informat Technol, Dept Chem Engn, Private Bag X20, ZA-0028 Hatfield, South Africa

[2] Univ South Africa UNISA, Sch Agr & Environm Sci, Dept Environm Sci, POB 392, ZA-1710 Florida, South Africa

[3] ROC Water Technol, POB 70075, ZA-0041 Pretoria, South Africa

关键词: Acid mine drainage;    Arsenic;    Adsorption;    Aluminium;    Ferric oxide-hydroxide;   

DOI  :  10.1016/j.jhazmat.2021.125491

来源: Elsevier

【 摘 要 】

This 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 (Delta G degrees), negative enthalpy change (Delta H degrees), and positive entropy change (Delta S degrees) - 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.

【 授权许可】

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