Development of Bacterial Augmented Floating Treatment Wetlands System (FTWs) for Eco-Friendly Degradation of Malachite Green Dye in Water

Abstract

Industrial revolution has intensified water pollution due to the indiscriminate discharge of untreated industrial effluents into water bodies, posing a serious threat to the whole ecosystem. Recently, the floating treatment wetlands system (FTWs) technique has been used as one of the most innovative, cost-effective and environment-friendly option for wastewater treatment. The present study is aimed at investigating the Malachite green (MG) dye decolorizing potential of Eichhornia crassipes (water hyacinth) through the development of a bacterial augmented FTWs. To an artificial FTWs, vegetated with E. crassipes and bioaugmented with Pseudomonas putida and Pseudomonas sp., synthetically prepared MG dye enriched wastewater was added. Among all the treatments developed, floating wetlands treatment T2 (consisting of dye, E. crassipes and Pseudomonas putida) performed the best in decolorizing the dye and in reducing values of electrical conductivity (EC), pH and total dissolved solids (TDS) of the treated water. Bacterial inoculation proved fruitful in assisting the increased MG dye decolorization in partnership with E. crassipes and also helped in aquatic plant growth promotion. MG dye toxicity effects were studied through phytotoxicity assay using FTWs treated water on Pisum sativum seeds, and satisfactory results were obtained. From experimental results, it can be seen that Eichhornia crassipes with bacterial inoculation have a strong ability to degrade and decolorize MG dye in textile effluents. We conclude that the plant-microbial assisted FTWs technique can be a unique approach to remediate the textile dye effluents before their release into water bodies.