Remediation of Textile Dyes Mixtures Using Tio2/Vis Photocatalysis and Fenton Fe2+/H2o2

Abstract

This study aimed to use the following treatment technology: TiO 2 photocatalysis and Fenton reaction for the remediation of mixture of textile dyes. For the photocatalytic treatment it was obtained a reduction in color of 80% and Chemical Oxygen Demand of 60% using for this 600 mg L

Cosmetic wastewater primary treatment by fenton process and final polishing adsorption

“…It is important to highlight that the presence of hydrolysed ferrous ions produces a series of complexes which plays the role of a flake-maker coagulants, which somehow enhances the removal efficiency in the turbidity and absorbance. This procedure demonstrates the dual ability of the Fenton process in acting as both chemical oxidation process and coagulation/flocculation process (MORAIS; BRITO, 2015).…”

“…According to Ragasson (2013), to achieve greater efficiency of Fenton's reagent, the typical ratio of [Fe+2] and [H2O2] must be in the range of 1:5 to 1:10. Nevertheless, it is known this ratio depends on the nature of the effluent and its organic load (ANDRADE et al, 2015;OLIVEIRA et al, 2015;FONTMORIN;SILLANPÄÄ, 2017). The relation between Fe2+ ions and hydrogen peroxide presented after Fenton process for cosmetic effluent, was 1: 7.06.…”

“…According to Andrade et al (2015), Wang et al (2016) and Ma & Xia (2009), Equation 1and 2 describes the interaction of ferrous ions acting as radicals scavenger (•OH/HO2•), when there is high iron concentration in the system, producing Fe3+ and OH-ions:…”

“…The excessive increase of Fe2+ ions in the system , also interfere in the turbidity removal, since Fe2+ ions undergo Fe3+ oxidation In this case, there is formation of iron hydroxides (Eq. 5-7), which may increase the turbidity of the system (MORAIS; BRITO, 2015).…”

“…However, the increase in dissolved oxygen concentration (7.57 mg L-1) may have occurred not only by the mineralization of organic compounds, but also by the generation of molecular oxygen in Fenton oxidation/reduction reactions during Fe2+ ion regeneration reactions (Eq. 20 and 21) (MORAIS; BRITO, 2015) and through intermediate species (Eq. 10 and 11) (PLIEGO et al, 2015).…”