Work

Sequential Fenton–ozonation treatment of textile wastewater: treatment performance and operational trade-offs

Year: 2026

Type: article

Abstract: Textile wastewater is a complex industrial effluent containing organic pollutants, colour, suspended solids, dissolved salts, surfactants, and recalcitrant compounds. This study evaluated sequential Fenton oxidation followed by ozonation for the treatment of textile wastewater collected from the influent of a full-scale textile common effluent treatment plant, with chloride and alkalinity concentrations of 1660 and 644 mg L⁻¹ , respectively. Triplicate 1-L batch Fenton experiments evaluated pH (3.0–7.6), Fe²⁺ concentration (100–300 mg L⁻¹), H₂O₂ dosage (350–1750 mg L⁻¹), and reaction time (30–150 min). The Fenton-treated wastewater was ozonated at O₃ production rates of 0.25–1.25 g h⁻¹ for 10–60 min. Performance was assessed using chemical oxygen demand (COD), biochemical oxygen demand (BOD), total organic carbon (TOC), colour, turbidity, total suspended solids (TSS), PO₄³ ⁻–P, oxidant efficiency, estimated ozone transfer, and recovered dry solids. The selected Fenton conditions of pH 3, 200 mg L⁻¹ Fe²⁺, 1750 mg L⁻¹ H₂O₂, and 60 min achieved removals of 73.19% COD, 69.01% BOD, 81.53% TOC, 93.63% colour, 67.39% turbidity, 75.16% TSS, and 98.81% PO₄³ ⁻–P. Oxidant efficiency decreased from 1.29 to 0.33 mg COD removed per mg H₂O₂ as the dosage increased from 350 to 1750 mg L⁻¹ . Ozonation at 1.25 g h⁻¹ for 60 min reduced COD, BOD, and TOC to 75.42, 45.80, and 44.86 mg L⁻¹ and colour to 8.00 Pt–Co units, corresponding to overall removals of 90.68%, 80.12%, 88.34%, and 99.37%, respectively. Dry Fenton sludge (0.71 g L⁻¹) and additional post-ozonation solids (0.17 g L⁻¹) were recovered. Overall, the sequential process effectively combined Fenton-based primary treatment with ozone polishing, achieving substantial improvements in final effluent quality and providing practical insight into the balance between treatment performance, reagent use, ozone exposure, and operational requirements.

Source: Desalination and Water Treatment

DOI: 10.1016/j.dwt.2026.102001