Electrochemical regeneration of carbendazim-loaded granular activated carbon

ABSTRACT

This study explores the use of in situ electrochemical process to regenerate granular activated carbon (GAC) loaded with carbendazim (CBZ) and simultaneously oxidize the contaminant. The experiment optimized the flow rate ($\mathit{Q}$), current density ($\mathit{j}$), cathodic or anodic chamber, and electrolyte type to achieve the best results. The study found that using GAC in the cathodic chamber and NaCl as a supporting electrolyte, with a $\mathit{j}$ = 0.5 mA cm⁻², and $\mathit{Q}$ = 100 L h⁻¹, led to a 64% regeneration with an energy consumption of 0.15 kWh kg⁻¹, which is at least 16× lower than those found in the literature for electrochemical, microwave and thermal processes. Consecutive regeneration tests revealed a decrease in GAC adsorptive capacity over time due to blockage by transformation products, and mainly by oxidation-induced changes in pore structure, as confirmed in dissolved organic carbon (DOC), scanning electron microscopy (SEM), and surface area results. The results also showed that in all tested conditions, residual CBZ was not found in the electrolyte solution. Overall, electrochemical regeneration proved to be an energy-efficient method for extending the lifespan of GAC and minimizing disposal in landfills.

KEYWORDS:

• Carbendazim
• granular activated carbon
• electrochemical regeneration
• regeneration mechanism

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Correction

Acknowledgments

The authors thank CAPES, CNPq, FAPERGS and FINEP for their financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article was originally published with errors, which have now been corrected in the online version. Please see Correction (http://dx.doi.org/10.1080/01496395.2024.2349145)

Additional information

Funding

The work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS) and Financiadora de Estudos e Projetos (FINEP).