Removal of dyes from waste water using metal oxide based nanomaterials

Abstract

Treatment of dyes present in wastewater has become necessary from a toxicological and environmental viewpoint. Keeping in view the importance of nanotechnology for dealing with water pollution and the applicability of metal oxides nanomaterials (NMs) for the removal of contaminants in wastewater, the following work was undertaken. In this perspective, various metal oxides NMs viz. CuO, ZnO, and#945;-Bi2O3 and and#945;-Bi2O3-ZnO composite were fabricated by using different solution based synthetic routes. Further, the environmental remediation activities of as-fabricated NMs towards harmful dyes and pathogenic bacteria were studied. Owing to their morphology, smaller size and relatively high surface area, CuO NMs prepared by CPM method showed relatively higher adsorption efficiency for the removal of harmful dyes (BBR-250 and DR-81) and antibacterial activity (S. aureus). The as-synthesized CuO NMs were further used as a catalyst for degradation of Victoria Blue (VB) and DR-81 dyes and results demonstrated that the synergistic effect of CuO NMs and sonocatalysis was more effective in degrading both the dyes as compared to CuO NMs and photocatalysis. Similarly, with the aim to deal with dye pollution, and#945;-Bi2O3-ZnO nanocatalyst was fabricated with the objective to synergistically combine the strengths of both the semiconductors to promote greater separation of photo-induced charge carriers. The results revealed that the photocatalytic efficiency of and#945;-Bi2O3-ZnO composite was greater than pure and#945;-Bi2O3 and ZnO under UV irradiation exposure. In order to increase the industrial practicability and large-scale application of MOs NMs for environmental remediation ZnO, NMs were immobilized on natural fiber extracted from S. trifasciata plant by employing different fabrication methodologies. The research was directed towards the development of highly functionalized material thus paving the way to low-cost, high-performance devices for wastewater treatment beyond the range of conventional technology. newline