VISIBLE-LIGHT PHOTOCATALYTIC REMOVAL OF DYES FROM TEXTILE EFFLUENTS

Abstract

Textile industries release dye-contaminated wastewater which is a dangerous environmental issue because synthetic dyes are highly stable, toxic, and non-biodegradable. A visible-light-active iron oxide (Fe₂O₃) photocatalyst was prepared in this research through a green, environmentally friendly, co-precipitation technique with the use of Azadirachta indica (neem) leaf extract as a natural reducing and stabilizing agent. The structure, morphology and optical characteristics of the prepared photocatalyst were analytically described by XRD, SEM and FTIR, UV-Vis spectroscopy, and showed the establishment of a crystalline phase of iron-oxide and surface functional groups that allow adsorption of the dyes and photocatalysis. Degradation of classic textile dyes was assessed under the irradiation of visible light to measure the photocatalytic performance of degrading the following dyes; Methylene Blue, Rhodamine B, and Congo Red. The findings revealed quick and effective dye degradation with the efficiencies of removal surpassing above 95% under the ideal of conditions, and according to pseudo-first-order kinetics. Radical scavenging studies indicated that the predominant reactive species was the superoxide radicals; the other reactive species that acted in the degradation process included hydroxyl radicals and photogenerated holes. The photocatalyst had high stability and reusability even after several cycles without much loss of activity. Notably, the workability of the system in terms of real textile wastewater was also tested, and the results of the experiment were almost 90 percent degradation efficiency with the complex effluent structure. The results indicate that green-synthesized Fe₂O₃ has a great potential to be used as an effective, sustainable, and cost-effective visible-light photocatalyst in the purification of textile wastewater.