Advanced catalytic oxidation process based on a Ti-permanganate (Mn/Ti-H⁺) reaction for the treatment of dye wastewater

Abstract

This article discusses the titanium (Ti)-based permanganate advanced catalytic oxidation process (ACOP) for the possible recovery of thousands of tons of dye wastewater. The heterogeneous catalyst TiO 2 in the solid state employed in the liquid phase reaction mixture with dye and potassium permanganate was recovered and reused several times for reproducible results. The kinetics were examined at various operational parameters like the effect of dyes, the effect of oxidants, the amount of catalysts, and the effect of acids, temperature, and various organic and inorganic additives used in the textile industry. The kinetics of advanced oxidation and the mechanism of dye de-coloration and degradation were monitored using the Congo red (CR) dye as a model in an aqueous medium and then applied to other dyes and real dye wastewater samples. The color removal was up to 98%, with the removal efficiency being linear with the dose at a particular time. This method could exhibit the complete color removal of the dye wastewater, leading to mineralization coupled with a change in the oxidation state of Mn from +7 to +2. The method also improved the BOD/COD ratio, followed by an increase in the salinity of the recycled water. This indicated that this method can be used not only for the highly efficient decolorization of dye wastewater but also as a preliminary step for the utilization of the dye wastewater after its recycling. The newly developed system was proven to be very cost-effective and eco-friendly with low sludge quantity, which contained numerous nitrogenous compounds, and this was validated by FTIR and HPLC analyses; thus, the system may be used in treatment plants for the recovery of wastewater.

Chemical Degradation and Decolorization of Reactive Black B With an Inorganic Oxidant in Acidic Medium

“…It means that almost complete decolorization of dye was achieved at 318 K. These results showed low temperature inhibit the decolorization of dye, while higher temperature is favorable. The results are in consistent with the earlier work reported [25,33,41–47] …”

“…The high values of TDS reduces the penetration of solar radiation into the water causing decline in the photosynthesis process in marine life. [25,52] To overcome this problem, the oxidizing property of BrO 3…”

“…To remove the color of dye from water, the azo bond needs to be broken by an oxidant. [25,26] In the current probe the oxidizing characteristic of the acidified KBrO 3 was examined as a potential tool for the decolorization of dye in the industrial wastewater. To evaluate the efficacy of each parameter on the dye degradation, experiments were performed as a function of various parameters such as concentration of dye and oxidant, pH, temperature and ionic strength.…”

“…The FT‐IR spectra of original RB−B dye (Figure 12a) showed characteristic peaks at 3458.37 cm −1 (N−H stretching), 2924.09 cm −1 ( stretching vibrations of CH 2 ), 1635.64 cm −1 (C=C strech), 1525.69 cm −1 (N=N streching), 1109.07 cm −1 (S=O). The peak at 522.71 cm −1 was due to the C−H deformation of benzene ring [25,33,41] …”

“…The values of EC (Table 3) increases, which proved the decay of dye and hence ultimately decreasing the contamination of dye molecule. The high values of TDS reduces the penetration of solar radiation into the water causing decline in the photosynthesis process in marine life [25,52] . To overcome this problem, the oxidizing property of BrO 3 − was used to degrade dye causing decrease in the values of TDS [55] .…”