Advanced chemical oxidation of reactive dyes in simulated dyehouse effluents by ferrioxalate-Fenton/UV-A and TiO2/UV-A processes (original) (raw)
Related papers
2000
Eective degradation of various mono-and bifunctional aminochlorotriazine reactive dyes in simulated dyehouse wastewater was achieved by the application of ferrioxalate-photo-Fenton [Fe(C 2 O 4) 3 3À /H 2 O 2 /UV-A; 300 nm>l>400 nm] and titanium dioxide-mediated heterogeneous photocatalytic (TiO 2 /UV-A) treatment processes. These so-called advanced oxidation processes were studied in a novel batch photoreactor that was irradiated by a solar simulating installation. Decolorization by the ferrioxalate-photo-Fenton oxidation process was found to proceed three times faster than the photocatalytic process, while the latter was more ecient in reducing the optical density at 280 nm wavelength (UV 280nm). Complete decolourization and partial mineralization with 17±23% total organic carbon (TOC) and 73± 86% UV 280nm removals were achieved by the ferrioxalate-Fenton/UV-A and TiO 2 /UV-A processes, respectively, within a 1-h treatment time. Emphasis was placed on the eect of dyehouse euent strength on decolourization kinetics, along with possible advantages of the ferrioxalate-Fenton/UV-A process over the conventional photo-Fenton (Fe 2+ /H 2 O 2 /UV-C) process. The results of these experiments showed that the more dilute the dyehouse euent the faster the decolourization rate. On the basis of spectrophotometric measurements, dye decomposition could be successfully ®tted to the empirical Langmuir±Hinshelwood kinetic model.
Photocatalytic Decomposition of Organic Dyes
Organic Pollutants in Wastewater I, 2018
Effluent detoxification and degradation kinetic of Acid Yellow 216 were investigated using Fenton and photo-Fenton processes. pH, contact time, Fe +2 concentration, H 2 O 2 concentration, dye initial concentration, and temperature were optimized. The decolorization (87%) was considerably higher under experimental conditions of 20 min irradiation, pH 3, 50 mg/L initial dye concentration, 1.5 mM Fe +2 , 5 mM H 2 O 2 and 40ºC temperature. However, in the photo-Fenton process dye degradation was achieved up to 98%. Among, first-order, second-order and Behnajady-Modirshahla-Ghanbery (BMG) kinetic models, BMG kinetic model fitted well to experimental data. Under optimized conditions, up to 83 and 94% degradation of textile effluents were achieved using Fenton and Photo-Fenton process along with 56 and 76% COD reduction, respectively.
Modeling dye degradation kinetic using dark- and photo-Fenton type processes
Chemical Engineering Journal, 2009
were applied for the treatment of model colored wastewater containing two reactive dyes, C.I. Reactive Blue 49 and C.I. Reactive Blue 137, and degradation kinetics were compared. Dye degradation was monitored by the means of UV/VIS, adsorbable organic halides (AOX) and total organic carbon (TOC) analysis, thus determining decolorization and dechlorination of triazine structure, as well as mineralization of model colored wastewater. Both dark-and photo-Fenton type processes were proven to be very efficient for color removal; ≥98% was achieved in all cases. Significant improvements in the mineralization of studied dyes were achieved by the assistance of UV light, as it was expected. It was demonstrated that the degradation kinetic of applied dyes depended on the presence of UV light, as well as type of iron catalyst and dye structure. On bases of the obtained experimental results, the mathematical models were developed describing dye degradation kinetics in all studied systems. Since UV light was used in order to enhance the efficiency of dark-Fenton type processes, mathematical model describing dye degradation by UV photolysis providing the values of quantum yields for each of the dye was developed and incorporated in model for photo-Fenton type processes. A sensitivity analysis for the evaluation of importance of each reaction used in mathematical models was also performed.
Chemical Industry, 2015
The effectivness of UV/H2O2 process, Fenton and photo-Fenton process at decolorization of commercially important textile dyes Reactive Orange 4 (RO4) and Reactive Blue 19 (RB19) was evaluated. The effect of operational condition such as initial pH, initial H2O2 concentration, initial Fe2+ concentration and initial dye concentration on decolorization of RO4 and RB19 was studied. The photo-Fenton process is found to be more efficient than UV/H2O2 and Fenton process for decolorization of simulated dye bath effluent and solutions of the dyes in water alone under optimum conditions. In simulated dye bath the removal efficiency was slightly lower than for the solutions of the dyes in water alone for both dyes types. The results revealed that the tested advanced oxidation processes were very effective for decolorization of RO4 and RB19 in aqueous solution.
Coloration Technology, 2004
The degradation of two commercial reactive dyes, CI Reactive Red 141 (homo‐bireactive) and CI Reactive Red 238 (hetero‐bireactive), using Fenton's reagent in the dark and under either artificial or solar irradiation, has been investigated. The main parameters that govern the complex reactive system, i.e. type of irradiation, temperature and initial concentrations of iron(II) and hydrogen peroxide, have been studied at pH 3. Temperature and the use of light have beneficial effects on the removal of colour, aromatic compounds, total organic carbon, acute toxicity, given as changes in EC50 values (against the marine photobacteria Vibrio fischeri) and changes in the biodegradability. The advanced oxidation processes used in this study have proven to be highly effective for the treatment of such types of reactive dyes and several advantages concerning the technique application arise from the study. The possibility of a combined advanced oxidation process‐biological treatment is propo...
Solar Energy, 2004
The degradation of different commercial reactive dyes: a monoreactive dye (Procion Red H-E7B), an hetero-bireactive dye (Red Cibacron FN-R) and a Standard Trichromatic System, by using solar light assisted Fenton and photo-Fenton reaction is investigated. The reaction efficiencies have been compared with the ones obtained for the same system in the dark or under the assistance of an artificial light source. The use of solar light is clearly beneficial for the removal of color, aromatic compounds (UV 254 ), total organic carbon (TOC), and the increase of the BOD 5 /COD ratio. The possibility of a combined advanced oxidation process (AOP)/biological treatment based on the use of sunlight is suggested.
International Journal of Environmental Research and Public Health, 2019
The fungal metabolite 3-hydroxyanthranilic acid (3-HAA) was used as a redox mediator with the aim of increasing dye degradation by Fenton oxidative processes (Fe2+/H2O2, Fe3+/H2O2). Its Fe3+-reducing activity can enhance the generation of reactive oxygen species as HO● radicals. Initially, the influence of 3-HAA on decolorization kinetics of five dyes (methylene blue, chromotrope 2R, methyl orange, phenol red, and safranin T) was investigated using decolorization data from a previous work conducted by the present research group. Fe3+-containing reaction data were well fitted with first-order and mainly second-order kinetic models, whereas the BMG (Behnajady, Modirshahla and Ghanbary) model obtained optimal fit to Fe2+. Improvements in kinetic parameters (i.e., apparent rate constants and maximum oxidation capacity) were observed with the addition of 3-HAA. In another set of experiments, a decrease in apparent activation energy was observed due to introducing 3-HAA into reactions con...
Degradation of Reactive Dyes Using Advanced Oxidation Method
CLEAN – Soil, Air, Water, 2015
In this study, the photo‐Fenton process was used to identify degradation conditions of Reactive Blue 19 (RB19) and Reactive Red 21 (RR21). The effects of pH, initial H2O2 and FeSO4 concentrations, time, and UV light intensity in determining the degradation rate were studied. The optimal conditions for the degradation of 0.156 mmol L−1 RB19 and 0.036 mmol L−1 RR21 in water were found to be: pH 4, 0.1 mL 30% H2O2 for RB19 and RR21, 0.2 mL 0.5% FeSO4 for RB19 and 0.1 mL 0.5% FeSO4 for RR21, 20 mL volume, and a temperature of 20°C. Optimal conditions were applied to synthetic dye wastewater using small amounts of H2O2 in 1 L for degradation. The degree of degradation efficiency of synthetic wastewater by the photo‐Fenton process was found to be >95% within 10 min.
Decolorization kinetics of Procion H-exl dyes from textile dyeing using Fenton-like reactions
Journal of Hazardous Materials, 2006
The decolorization kinetics of three commercially used Procion H-exl dyes was studied using a Fenton-like reagent. The effect of the major system parameters (pH, concentration of H2O2 and Fe3+ and initial dye concentration) on the kinetics was determined. For comparison, the effect of the use of UV irradiated Fenton-like reagent and of Fenton reagent on the kinetics was also examined. In addition, mineralization rates and the biodegradability improvement as well as the effect of the addition of Cl−, CO32− or HCO3− on the decolorization rates was studied. The reactions were carried out in a 300 ml stirred cylindrical reactor with the capability of UV irradiation. The dye half-life time goes through a minimum with respect to the solution pH between 3 and 4. It also exhibits a broad minimum with respect to Fe3+ and H2O2 at molar ratios of H2O2/Fe3+ from about 100 to 10. The addition of CO32− and HCO3− substantially reduces the decolorization rates, while this effect is significantly less pronounced with Cl−. At an optimum range of parameters, the mineralization rate (TOC reduction) is very slow for the Fenton-like process (TOC decrease from an initial 49.5 to 41.1 mg/l after 30 min and to only 35.2 mg/l after 600 min), but it increases significantly for the photo-Fenton-like process (to TOC values of 39.7 and 11.4 mg/l, respectively). The biodegradability, as expressed by the BOD/COD ratio, increases significantly from an initial value of 0.11–0.55 for the Fenton-like and to 0.72 for the photo-Fenton-like processes.
Photocatalytic Decolourization of Textile Effluent Containing Reactive Red 120 Dye with UV/TIO2
American Journal of Engineering and Applied Sciences, 2013
The efficiency of degradation of an aqueous solution of reactive red 120 dye using Advanced Oxidation Process (AOP) was evaluated. A low pressure UV lamp and a combination of UV/TiO 2 were tested using ten different dye concentrations (50-500 mg/L) at several retention times (5.2-60 min) a pH of 10.5. The effect of acidic pH (pH = 3) on dye removal efficiency and the Chemical Oxygen Demand (COD) of the treated effluents were also investigated. When the alkaline (pH = 10.5) reactive red 120 dye solutions were treated using a low pressure (380 nm intensity) UV lamp, a maximum degradation efficiency of 27.01% was obtained for the least concentrated dye (50 mg/L) solution and only a degradation efficiency of 0.33% was obtained for the most concentrated (500 mg/L) dye solution. When the alkaline (pH = 10.5) reactive red 120 solutions were exposed to a combination of UV/TiO 2 , a maximum degradation efficiency of 46.70% was obtained for the lease concentrated (50 mg/L) dye solution after 60 min and only a degradation efficiency of 2.84% was obtained for the most concentrated (500 mg/L) dye solution after 60 min. When the pH of the reactive red 120 dye solution was reduced to 3, a degradation efficiency of 56.45% was obtained for the least concentrated (50 mg/L) dye solution at 60 min and a degradation efficiency of 14.94% was obtained for the most concentrated (500 mg/L) dye solution at 60 min. However, the increase in degradation efficiency obtained in this study does not justify the cost of chemicals added to adjust the pH to 3 before treatment and then to 7 before final disposal. Also, the addition of chemicals (to adjust the pH) increases the COD of the dye solution thereby necessitating a further costly treatment.