Efficiency comparison of ozonation, photolysis, photocatalysis and photoelectrocatalysis methods in real textile wastewater decolorization

Abstract

Treatment of real effluents from industries using AOPs stands to be an imperative task of crucial importance yet quite huge a challenge largely given the nature of complexity of these wastewaters. The present work sought to develop a versatile system aimed at the treatment of real wastewater using a bubbling annular reactor, which enables us to test the efficiency of photolysis; photocatalysis, photoelectrocatalysis and direct ozonation using oxygen or ozone as gas flow. A TiO2 nanotubes electrode was used as photocatalyst in photocatalytic and photoelectrocatalytic measurements with and without coupling with ozonation under pH 3.0 and pH 8.0 leading to 50% of color removal after 60 min reaction. However, the results indicated 90% of color removal upon the bubbling of ozone after 15 min of treatment. A synergistic effect was observed in all experiments using the AOPs in the presence of ozone under both pH values. Interestingly though, 85% of decolorization was obtained through direct ozonation without any change in the effluent following 10 min of treatment. The results were discussed in terms of electric energy per order and were compared to those reported previously. For real textile wastewater, ozonation appears to be a promising candidate for full-scale effluent decolorization.

Probing the activities of UV and visible-light absorbing photocatalyst powders using a resazurin-based photocatalyst activity indicator ink (Rz Paii )

“…If the excitation light does comprise a significant level of photons of wavelengths which will be strongly absorbed by the dye, then a non-photocatalytic, dye-bleaching processes, such as dye photolysis [9,10], or dye-photosensitisation [8,11,12], can be very effective in bleaching the dye.…”

Evaluate the Performance of Fenton Process for the Removal of Methylene Blue from Aqueous Solution: Experimental, Neural Network Modeling and Optimization

“…Because of the circular structure of colored compounds, the potential for biodegradability and the toxicity of some dyestuffs, aerobic biological treatment has a limited effect on the removal of dye in these wastewater, and in anaerobic conditions, it can also be revived to dangerous intermediates such as aromatic amines . Considering the drafted strict rules regarding the evacuation of wastewater from textile units, it is important to achieve the standard of discharge by employing cost effective and cost effective methods . Among the methods used to treat hazardous waste from effluent since 1990 are advanced oxidation processes (AOPs), such as the Fenton process.…”

Tratamiento De Aguas Residuales De La Industria Textil Mediante Coagulación Química Acoplada a Procesos Fenton Intensificados Con Ultrasonido De Baja Frecuencia

“…De 100 a 200 L de agua son necesarios para producir un kilogramo de productos textiles (Carvalho et al 2016). El agua residual resultante está altamente contaminada debido a la presencia de colorantes, surfactantes, sales inorgánicas y distintos compuestos químicos empleados en el proceso productivo (Buscio et al 2015).…”