Harnessing Pseudomonas aeruginosa for Bioremediation: Comparative Study on the Removal of Indigo Carmine and Safranine-T Textile Dyes

Abstract

Dyes are a major source of contamination in industrial wastewater, posing significant challenges for effective remediation due to their structural resilience, low biodegradability, recalcitrant behavior, and toxic properties. Given the limitations of conventional treatment methods, recent research has increasingly focused on developing innovative, sustainable, and environmentally friendly solutions to address this pressing issue. This study investigates the potential of Pseudomonas aeruginosa in biological remediation by comparing two textile dyes: the anionic indigo carmine (IC) and the cationic safranine-T (ST). The influence of different initial dye concentrations (50, 100, 150, and 500 mg L^–1), agitation rates (static vs 125 rpm), and growth medium concentrations (25 vs 50 g L^–1) was also assessed. It was found that P. aeruginosa achieved >96% decolorization of IC within 8 h under agitation, with a decolorization rate of 60.27 mg L^–1 h^–1. In contrast, ST showed limited removal (77.2%) only in the lowest dye concentration and highest medium concentration. Agitation consistently enhanced dye removal, with IC likely metabolized as an energy source, while ST removal was attributed to biosorption. Second-order kinetic models best described the decolorization process. These findings highlight the potential of P. aeruginosa as biological resources for efficient, sustainable wastewater treatment, offering a viable alternative to conventional methods and contributing to environmental sustainability. Further optimization of process conditions could broaden its application in industrial effluent management.