Details

Autor(en) / Beteiligte

• Gonçalves, Nuno P.F.
• Almeida, Mariana M.
• Labrincha, João A.
• Novais, Rui M.

Titel

Effective acid mine drainage remediation in fixed bed column using porous red mud/fly ash-containing geopolymer spheres

Ist Teil von

• The Science of the total environment, 2024-08, Vol.940, p.173633, Article 173633

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Acid mine drainage (AMD) poses a significant threat to water quality worldwide, being amongst the most problematic environmental concerns of the millennium. This work reports for the first time the remediation of real AMD, from a Portuguese abandoned mine, in fixed bed column using porous red mud/fly ash-based geopolymeric spheres. Porous waste-based spheres (2.6 ± 0.2 mm) were obtained by a suspension-solidification method through the addition of optimum foaming agent dosage. The sorbent capacity in removing cations from AMD was evaluated by targeting selected hazardous elements: Zn, Cu, Co, Pb and Ni, based on their occurrence in the effluent and potential hazard. The spheres exhibited a dual mechanism of action, simultaneously neutralizing the acidic sample while removing cations through adsorption achieving removal efficiencies between 51 % and 80 %. Other elements present in high levels, such as iron were efficiently removed (>96 %). The role of precipitation, due to the pH neutralization, and adsorption was determined. The sorbent regeneration and reusability were evaluated for up to five cycles. Moreover, the effectiveness of waste-based geopolymers treating distinct AMD waters due to seasonal variations was also evaluated, further demonstrating the effectiveness of the proposed strategy to address environmental concerns stemming from mining activities. [Display omitted] •Red mud/fly ash-based porous spheres were prepared by suspension-solidification method.•Spheres were investigated for the treatment of acid mine drainage water samples.•A synergistic effect of pH neutralization and adsorption was demonstrated.•The role of precipitation and adsorption in cations removal was assessed.•Regeneration and reusability for consecutive treatment cycles were evaluated.