Degradation of aqueous Acid Red 183 textile dye and acid dye-bath effluent by Fenton-like and Photo-Fenton-like advanced oxidation processes

The present experimental study aimed at investigating color and organic carbon (TOC, COD) removal from the chromium(III)-complex azo dye Acid Red 183 and a simulated acid dye-bath effluent using Fenton-like and Photo-Fenton-like processes. In the case of Acid Red 183 dye, the Fenton-like reagent was capable of 98% color and 56% TOC removal, after 40 min treatment under optimized working conditions (pH_o 2.8; Fe³⁺_,o 3 mmol L ^-1; H₂O_2,o 30 mmol L^-1 for 100 mg L^-1 dye), whereas UV-A assisted Fenton-like treatment proceeded significantly faster. At pH_o 2.8, Fe³⁺_,o 0.3 mmol L^-1 and H₂O_2,o 30 mmol L^-1, 48% color and 14% TOC removal rates were achieved after 20 min of Photo-Fenton-like oxidation of 100 mg L^-1 aqueous Acid Red 183, instead of only 23% color and 6% TOC removals obtained by the dark Fenton-like treatment for the same reaction period. For the simulated acid dye-bath effluent subjected to Fenton-like treatment at varying Fe³⁺ concentrations, 86-97% color removal accompanied with 47% COD abatement were obtained under the working conditions of pH_o 3; Fe³⁺_,o 5 mmol L ^-1 and H₂O_2,o 30 mmol L^-1.