Fenton oxidation of cork cooking wastewater—overall kinetic analysis

• Published in: Water research (Oxford) Vol. 37; no. 13; pp. 3061 - 3069
• Main Authors: Guedes, Anabela M.F.M., Madeira, Luis M.P., Boaventura, Rui A.R., Costa, Carlos A.V.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2003; Elsevier Science
• Subjects: Applied sciences; Cork cooking wastewater; Exact sciences and technology; Fenton's reagent; Hot Temperature; hydrogen peroxide; Hydrogen Peroxide - chemistry; Industrial Waste; Industrial wastewaters; Iron - chemistry; Kinetics; Oxidants - chemistry; Oxidation; Oxidation-Reduction; Phellodendron; Pollution; Waste Disposal, Fluid - methods; Wastewaters; Water Purification - methods; Water treatment and pollution; Portugal; Europe; Cork cooking wastewater; Oxidation; Kinetics; Fenton's reagent; Manufacturing industries; Industrial waste water; Cork; Fenton reaction; Physicochemical purification; Chemical degradation; Waste water purification; Operating conditions
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/S0043-1354(03)00178-7

In the present work, the possibility of using chemical oxidation through Fenton's reagent for the pre-treatment of cork cooking wastewaters was exploited. Aiming both the selection of the best operating conditions (pH, Fe 2+:H 2O 2 ratio and initial H 2O 2 concentration) and the evaluation of the overall reaction kinetics, trials were performed in a batch reactor. Operating at pH=3.2, H 2O 2 concentration=10.6 g/L and Fe 2+:H 2O 2 ratio=1:5 (by weight), about 66.4% of total organic carbon (TOC), 87.3% of chemical oxygen demand (COD) and 70.2% of biochemical oxygen demand (BOD 5) were removed and an increase of the BOD 5/COD ratio from 0.27 to 0.63 was achieved. In the temperature range 20–50°C, the best performance was obtained at 30°C. The kinetic study was undertaken at different initial TOC concentrations and temperatures. Overall kinetics can be described by a second-order followed by a zero-order rate equation and the apparent kinetic constants at 30°C are k=2.3×10 −4 L/mg min and k 0=26.0 mg/L min, respectively. The experiments performed at different temperatures confirmed the global kinetic model and allowed to calculate the global activation energy for the second-order reaction (70.7 kJ/mol).