Decolorization of azo dyes Orange G using hydrodynamic cavitation coupled with heterogeneous Fenton process

Abstract

The present work demonstrates the application of the combination of hydrodynamic cavitation (HC) and the heterogeneous Fenton process (HF, Fe(0)/H2O2) for the decolorization of azo dye Orange G (OG). The effects of main affecting operation conditions such as the inlet fluid pressure, initial concentration of OG, H2O2 and zero valent iron (ZVI), the fixed position of ZVI, and medium pH on decolorization efficiency were discussed with guidelines for selection of optimum parameters. The results revealed that the acidic conditions are preferred for OG decolorizaiton. The decolorization rate increased with increasing H2O2 and ZVI concentration and decreased with increasing OG initial concentration. Besides, the decolorization rate was strongly dependent on the fixed position of ZVI. The analysis results of degradation products using liquid chromatography-ESI-TOF mass spectrometry revealed that the degradation mechanism of OG proceeds mainly via reductive cleavage of the azo linkage due to the attack of hydroxyl radical. The present work has conclusively established that the combination of HC and HF can be more energy efficient and gives higher decolorization rate of OG as compared with HC and HF alone.

Comparing geometric parameters of a hydrodynamic cavitation process treating pesticide effluent

“…Thus, in present case, inlet pressure of 5 bars exists for both plate configurations and degradation of CPF. Similar observations of optimum inlet pressure are seen in treatment of brewery spent wastewater [31]; degradation of organic wastewater [32]; decolorization of azo dyes [33].…”

Removal of crystal violet from aqueous solutions using functionalized cellulose microfibers: a beneficial use of cellulosic healthcare waste

“…It has also been widely used as a disinfectant and fungicide in aquaculture due to low cost and high effectiveness 5 . In recent years, various treatment technologies have been developed for dye removal from industrial wastewaters which are classified as chemical (ozonation 8 , chemical oxidation 9 , electrochemical 10 , photocatalytic degradation 11 ), physical (adsorption 12 , coagulation/flocculation 13 , ion exchange 14 , membrane filtration 15 ) and biological 16 treatments. The variety of synthetic dyes has been observed in effluents of some industries such as coloring, textile and tanning.…”

Comparison of Fenton and Photo-Fenton Processes for Removal of Linear Alkyle Benzene Sulfonate (Las) from Aqueous Solutions

“…Moreover, literature shows that Fenton has been utilized to treat azo dyes, phenols, nitrobenzene, COD, herbicides, and Di-(2-Ethylhexyl) phthalate (DEHP), as well as to reduce linear alkylbenzene sulfonate (LAS) in wastewater [38][39][40][41][42][43]. The photo-Fenton process also has been utilized to treat inorganic and organic components in synthetic or real aqueous solutions such as LAS, COD, Metoprolol, TOC, and pesticides [39,42,[44][45][46][47].…”