Incorporation of activated carbon into red mud/fly ash-containing 3D-printed alkali-activated materials for enhanced acid mine drainage remediation

abstract

Alkali-activated materials have emerged as highly effective sorbents for metal removal, due to their zeolitic-like structure, intrinsic porosity and ion exchange properties. Combined with the sorbent benchmark activated carbon, these capabilities can be further enhanced. In this study, activated carbon was integrated for the first time into 3D-printed waste-based alkali-activated materials (incorporating biomass fly ash and red mud), and investigated their potential for treating real acid mine drainage waters. Activated carbon loadings of 10, 20, and 30 wt% were incorporated into a fly ash, red mud and metakaolin composition with a weight ratio of 30:40:30. The ink formulations were optimised by fine-tuning the liquid-to-solid ratio to ensure printability. As activated carbon content increased, the specific surface area of the materials improved significantly, from 40 to 95 m2/g. Incorporating 30 wt% of activated carbon notably enhanced the removal efficiency of target cations in a fixedbed continuous flow process. After 8 h of contact time, the removal rates for Fe, Cu, Zn, Mn, Ni, and Pb increased from 99 %, 55 %, 27 %, 38 %, 13 %, and 95 % (structure without activated carbon) to 99 %, 90 %, 82 %, 80 %, 69 %, and 96 % (structure with 30 wt% of activated carbon), respectively. This approach demonstrates the potential of combining a well-established sorbent, such as activated carbon, with waste-derived alkali-activated materials to significantly enhance the remediation of acid mine drainage, a critical global source of environmental pollution.

keywords

HEAVY-METALS; ADSORPTION; GEOPOLYMER; REMOVAL; METAKAOLIN; PERFORMANCE; WATERS; IONS

subject category

Engineering

authors

Almeida, MM; Gonçalves, NPF; Gameiro, T; Labrincha, JA; Novais, RM

Groups

G1 - Porous Materials and Nanosystems
G4 - Renewable Materials and Circular Economy

Projects

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Multifunctional bAuXite Inorganic polyMers for acid mine drainage treatment from PortUguese Mines (MAXIMUM)

3D Printed Fouling-Resistant Photoactive Membranes for Wastewater Treatment (PURAQUA)

acknowledgements

This work was developed within the scope of the project CICECOAveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020) , UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) , financed by National funds through the FCT/MCTES (PIDDAC) ; and FCT project MAXIMUM (PTDC-CTM-CTM-2205-2020, DOI 10.54499/PTDC/CTMCTM/2205/2020) . MA (2024.01820.BD) and NG acknowledge the funding from FCT and the European Union's Horizon Europe research and innovation programme under the Marie Sklodowska-Curie Actions PF grant agreement No 101065059 and FCT 2022.06593.CEECIND/CP1720/CT0024 (DOI 10.54499/2022.06593.CEECIND/CP1720/CT0024) . The support from Empresa de Desenvolvimento Mineiro (Portugal) and Dra. Catarina Diamantino in the AMD sampling acknowledged.r CP1720/CT0024 (DOI 10.54499/2022.06593.CEECIND/CP1720/CT0024) . The support from Empresa de Desenvolvimento Mineiro (Portugal) and Dra. Catarina Diamantino in the AMD sampling acknowledged.