Water pollution by the textile industry is an emerging issue. Textile industry is the major industrial sector which contributes to water pollution. Textile industry releases a huge amount of unfixed dyes in wastewater effluents. About 20% of the dye production all over the world is discharged as waste in industrial effluents by textile industry. These dyes are highly stable and colored substances which disturb the aqueous ecosystem significantly. Therefore, there is a need for methods to remove organic dyes from textile industrial effluents. Photo catalysis and catalytic wet oxidation are best practices for degradation of dyes in wastewater. In photo catalysis, the dye molecules can be completely degraded into inorganic non-toxic compounds by irradiation of the dye solution under visible or ultraviolet light in the presence of semiconductor metal-oxide photo catalysts. In catalytic wet oxidation, various metal-based catalysts in supported or unsupported form can be used as heterogeneous catalysts for degradation of dyes in the presence of oxygen or hydrogen peroxide. These processes have several preferences like easy separation of the catalyst from reaction mixture and recycling of the catalyst.
Part of the book: Photochemistry and Photophysics
Water pollution is one the fundamental problems that have got the serious concerns of the researchers. Water poluution arises due to a number of reasons including domestic, industrial, agricultural, scinec and technology. The textile industry is the main industry that releases the dyes contaminated wastewater to the environment. A varities of protocols have been attempeted for the removal of dyes from aqueous body. Photocatalysis is one of the effective techniques which offer opportunities to overcome the aqueous pollution caused by rapid industrialization and urbanization. The semiconductor metal oxides used as photocatalysts are capable to provide a sustainable and clean ecosystem due to the tunable physiochemical characteristics of semiconductor metal oxides. Titanium dioxide (TiO2) is one of the metal oxides that can be effectively employed as a photocatalyst in the abatement of aqueous pollution due to organic compounds. The catalytic performance of titanium dioxide depends on several parameters like its crystallinity, surface area, and morphology. Titanium dioxide has shown good performance in the different photocatalytic systems, however, the characteristics like wide band gap and low conductivity limit the photocatalytic performance of titanium dioxide. Various attempts have been made to improve the photocatalytic performance of titanium dioxide. Herein, we summarize the various attempts to improve the photocatalytic performance of titanium dioxide in the abatement of aqueous pollution. The attempts made for the improvement of photocatalytic performance of titanium dioxide include modifications in composition, doping of other metal, and formation of heterojunctions with other metal oxides.
Part of the book: Titanium Dioxide