The Comparison of Photocatalytic Degradation and Decolorization Processes of Dyeing Effluents

Abstract

Treatment of dye effluents resulting from the industrial scale dyeing of cotton, polyacrylic fibres, leather, and flax fabrics by photocatalytic methods was investigated. Photocatalytic processes were initiated by UV-a light (λmax366 nm) and were conducted in the presence of TiO2, TiO2/FeCl3, or FeCl3as photocatalysts. It was found that the photocatalytic process carried out with TiO2and TiO2/FeCl3was the most effective method for decolorization of textile dyeing effluents and degradation of dyes, except for effluents containing very high concentrations of stable azo dyes. During the photocatalytic degradation of anionic dyes, a mixture of TiO2/FeCl3was more effective, while in the case of cationic dyes, more suitable seems to be TiO2alone.

A New Mechanism of the Selective Photodegradation of Antibiotics in the Catalytic System Containing TiO2 and the Inorganic Cations

“…Increasing or decreasing the pH resulted in strong inhibition of the reaction. Analogous results were described for other reactants degraded in the presence of TiO 2 /Fe 3+ [18,20,[30][31][32][33][34]. According to the majority of researchers, this effect is likely related to the presence of photochemically active Fe(OH) 2+ ions in the Fe 3+ -salt solution at pH~3.…”

Role of Platinum Deposited on TiO2in Photocatalytic Methanol Oxidation and Dehydrogenation Reactions

“…Different attempts have been performed to improve the efficiency of TiO 2 depressing the recombination process of the photoelectron-hole pairs. Some of them include the modification of TiO 2 surface with other semiconductors to alter the charge-transfer properties between TiO 2 and the surrounding environment [22,23], sensitizing TiO 2 with colored inorganic or organic compounds improving its optical absorption in the visible light region [24][25][26][27][28], bulk modification by cation and anion doping [29][30][31][32][33][34][35][36][37][38], and fabrication of TiO 2 surface from polyhedral to produce hallow TiO 2…”

Trimetallic composite nanofibers for antibacterial and photocatalytic dye degradation of mixed dye water

“…Only a few reports (Adamek et al 2013 ; Akerdi et al 2020 ; Chomkitichai et al 2019 ; Gupta et al 2015b ; Xie et al 2018 ) are available in the literature on mixed dye removal and most of these reports demonstrate the removal of two dyes that is different from the dyes studied in this work. As can be seen from Table 2 , researchers have tried SrTiO 3 (Xie et al 2018 ), multi-phase BiVO 4 (Chomkitichai et al 2019 ), graphene nanosheets (Gunture et al 2019 ), and CoFe 2 O 4 –RGO (Moitra et al 2016 ) photocatalyst for removal of a binary mixture of MB and RhB and/or in combination with other dyes.…”

“…source Dye mixture Dye removal capacity Refs. SrTiO 3 synthesized using sodium carboxymethylcellulose Mercury lamp 365 nm RhB–MB binary solution ~ 100% in 180 min Xie et al ( 2018 ) Ag + doped TiO 2 UV lamp (365 nm) Crystal Violet and Methyl Red > 99% on UV irradiation for 90 min Gupta et al ( 2006 ) TiO 2 UV-a lamps Azodyes effluent from industry 28%(340 nm), 40(430 nm), 58(540 nm), 84 (610 nm) Adamek et al ( 2013 ) Multi–phase BiVO 4 UV lamp (254 nm) MB and RhB 74% and 21% for catalyst (0.8 g/L) 60 min Chomkitichai et al ( 2019 ) GO-TiO 2 -graphite electrode 9 W UV lamp MB and AR14 86.74% (MB) and 82.48% (AR14) in 67 min at pH 10 Akerdi et al ( 2020 ) Graphene nanosheets Sun light CV, RhB and MB ~ 99.9% in 180 min(MB) 225 min (RhB and CV) Gunture et al ( 2019 ) CoFe 2 O 4 –RGO (25%) catalyst 100 W reading lamp Methyl orange, Methylene blue, Rhodamine B 99.9% removal in 120 min Moitra et al ( 2016 ) PMMA Ag/ZnO/TiO 2 nanofibers Sun light MB, Au, FB, Rh Each 3 ppm 81.2% 66.0% 74.4% in 150 min <...>…”