Use of TiO₂ photocatalyst supported on residues of polystyrene packaging and its applicability on the removal of food dyes

Abstract

This work proposes the use of plastic residues, more specifically polystyrene packaging, to support TiO, used as a photocatalyst in the degradation of erythrosine and Brilliant Blue food dyes. The scanning electron microscopy and Fourier transform infrared spectroscopy analyses exhibited the surface coating and the presence of TiO in the material, respectively. The UV/HO/TiO process was used in the preliminary study, given the high percentage of degradation, operational advantages and greater reductions in peaks related to the aromatic rings when compared to the other processes studied. For the factorial design, the highest efficiency was reached for 150 mg of TiO, a HO concentration of 11.2 mmol L and pH of 5.0. These conditions were used in the degradation kinetics, which was rapid during the first 30 min, with the concentration of dyes in the solution reaching values close to zero after 180 min. Based on the mechanism proposed, the pseudo-first order kinetic model presented the best adjustment to the experimental data. After treatment, the solution presented greater biodegradability and lower toxicity, verified by the lettuce seed germination test (Lactuca sativa). Thus, the UV/HO/TiO process showed great potential in the treatment of industrial effluents contaminated by these food dyes, as well as in reusing discarded polystyrene packaging to support the photocatalyst.

Titanium dioxide immobilization in recycled aluminum net for degradation of textile dye by Heterogeneous Photocatalysis trough neural networks

“…This behavior was expected, since without radiation source, it is not possible to generate the free radicals (OH•) responsible for the organic dyes degradation. The same behavior was observed by Santos et al (2018) and Nascimento Júnior et al (2018) in their photocatalytic studies with dyes. In Figure 3, the degradation behavior of the RGY dye is represented for different AOP as a function of the experiment time.…”

“…Oancea and Meltzer (2013) perceived that the influence of the H 2 O 2 amount applied for synthetic dyes removal obtained best degradation percentages for higher oxidant dosages. Also Pajootan et al 2017, Santos et al (2018) and Gupta et al (2011) observed in their works that the TiO 2 increase caused higher efficiency on synthetic dyes removal in aqueous solution.…”

“…The negative control did not present germination and there was a growth of 0.6 cm for the sample after photocatalytic treatment comparing to the not treated sample. In the work of Santos et al (2018), that studied the removal of the synthetic dyes bright blue and erythrosine (60 mg.L -1 ) with titanium dioxide, a length variation of 0.43 cm between the treated and not treated samples was observed.…”

Evaluation of combined radiation for the treatment of lamivudine and zidovudine via AOP

“…These were exposed to solutions with the pharmaceuticals contaminants before and after being treated by the photoperoxidation and photo-Fenton processes. The toxicity assessment followed the methodology described by Santos et al [44].…”

Composites based on poly(ethylene-co-vinyl acetate) and silver-calcined scallop shell powder: Mechanical, thermal, photocatalytic, and antibacterial properties

“…Photocatalytic materials decompose organic dyes in different mechanisms based on their chemical nature, where the reliable mechanisms are electrons and holes generated from photocatalyst or active free radicals by UV–visible light which are responsible for catalytic decomposition reactions. 14,15 The presence of transition metals enhances the charge transfer and increases the photochemical degradation process. Rauf et al revealed transition metals dopped TiO 2 photocatalytic materials for the removal of organic dyes in wastewater.…”