Cavalcanti costa otimização da fotodegradação de corantes têxteis usando catalisador proveniente de pilha alcalina pós-consumo

Abstract

Textile effluents pose a serious environmental threat due to the presence of synthetic dyes, many of which are toxic and can harm human health and aquatic biodiversity. Effective solutions are urgently needed, as conventional methods have limitations in dye removal. New methods, such as Advanced Oxidative Processes, appear more promising, particularly with the use of heterogeneous photocatalysis with alternative catalysts. Recent studies have demonstrated that the direct application of catalysts obtained from alkaline battery waste presents an innovative and effective solution for dye degradation while allowing for battery component recycling. In this perspective, this research conducted a scientific literature review on the topic and investigated the applicability of an alternative catalyst, named in this study as AK1045, produced from the electrolyte paste of post-consumer Panasonic Alkaline batteries, in the solar photodegradation of methylene blue and rubine GDN dyes. The study employed a Central Composite Design (CCD), which allowed an investigation into the influence of the independent variables pH and catalyst concentration on the degradation of these dyes. A bibliometric survey from 2014 to 2024 across the Web of Science, Scopus, and Science Direct databases resulted in an analysis of heterogeneous photocatalysis with catalysts derived from alkaline battery waste, based on a bibliographic portfolio of seven articles. Experimental results showed that the alternative catalyst achieved up to 64.33% removal of methylene blue and 86.91% of rubine GDN in aqueous solution, with maximum efficiencies reached at pH 7 and concentrations of 2 and 3.41 g/L, respectively. Statistical analysis revealed that pH and catalyst concentration were significant factors in dye degradation. Optimal degradation conditions were found to be pH 6.90 and 2.52 g/L for methylene blue, and pH 7.23 and 3.41 g/L for rubine GDN. The AK1045 catalyst maintained over 48.22% efficiency up to the second cycle in both cases. Regarding the color number (CN) removal efficiency, rubine GDN reached its maximum efficiency of 88% at 120 minutes, while methylene blue stabilized around 61% after 150 minutes. Through the calculation of the integrated spectral area, a reduction of 47.24% for methylene blue and 78.77% for rubine GDN was observed with the catalyst, indicating a significant area reduction. This demonstrates that the strategy of converting waste into resources not only helps mitigate the environmental impacts caused by these materials but also reduces operational costs in wastewater treatment, offering a sustainable and efficient alternative for treating these effluents.