Effects of system parameters and inorganic salts on the photodecolourisation of textile dye Reactive Blue 19 by UV/H2O2 process (original) (raw)
Related papers
Chemical Engineering Journal, 2010
In this work, the decolorization of C.I. Acid Blue 25 (AB25), a commercially important anthraquinonic dye, by direct UV irradiation alone and UV/H 2 O 2 and UV/Fe(II) processes was investigated. Experiments were conducted in batch mode using a low-pressure mercury lamp emitting mainly at 253.7 nm. For direct UV photolysis, the decolorization rate increased with decreasing pH and initial dye concentration. The decolorization of AB25 was investigated using UV irradiation in the presence of H 2 O 2 as function of hydrogen peroxide concentration, dye concentration and pH. Additionally, the effect of salts on the bleaching of this dye was also studied. Decolorization rate was increased in the presence of UV/H 2 O 2 compared to UV irradiation alone. The results showed that the bleaching increases as the initial H 2 O 2 concentration increased up to a certain limit at which hydrogen peroxide reduced the bleaching by scavenging the OH radicals. The bleaching of AB25 decreased when the dye concentration increased. Decolorization rate by means of Fe(II) homogeneous photocatalysis under UV irradiation was increased compared to direct UV irradiation alone. The best working condition was found for an initial Fe(II) concentration of 30 mg L −1 .
Al-Nahrain Journal for Engineering Sciences
In this study sunlight and UV radiation were used to compare the efficiency of decolorization of textile wastewater containing brilliant reactive red dye K-2BP (λmax = 534 nm) by the advanced oxidation process (AOP) using (H2O2/sunlight, H2O2/UV, H2O2/TiO2/sunlight, and H2O2/TiO2/UV). The results studied the effect of solution pH, applied H2O2 concentration, TiO2 concentration (nanoparticle), and initial dye concentration were studied. The experimental results showed that decolorization percentage with H2O2/sunlight and TiO2/H2O2/sunlight under the following conditions: - reaction time 150 of minutes, [ 500 ppm] H2O2, [100 ppm] TiO2, pH=3, initial dye concentration =15 ppm and at ambient temperature were 95.7% and 98.42% respectively. For the same conditions using H2O2/UV, H2O2/TiO2 /UV, the percentage of decolorization were 97.85% and 96.33% respectively. The results also indicated that the sunlight is more economic and cost-effective than UV radiation.
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.
Solar light induced and TiO 2 assisted degradation of textile dye reactive blue 4
Chemosphere, 2002
Aqueous solutions of reactive blue 4 textile dye are totally mineralised when irradiated with TiO 2 photocatalyst. A solution containing 4 Â 10 À4 M dye was completely degraded in 24 h irradiation time. The intensity of the solar light was measured using Lux meter. The results showed that the dye molecules were completely degraded to CO 2 , SO 2À 4 , NO À 3 , NH þ 4 and H 2 O under solar irradiation. The addition of hydrogen peroxide and potassium persulphate influenced the photodegradation efficiency. The rapidity of photodegradation of dye intermediates were observed in the presence of hydrogen peroxide than in its absence. The auxiliary chemicals such as sodium carbonate and sodium chloride substantially affected the photodegradation efficiency. High performance liquid chromatography and chemical oxygen demand were used to study the mineralisation and degradation of the dye respectively. It is concluded that solar light induced degradation of textile dye in wastewater is a viable technique for wastewater treatment. Ó
Degradation and toxicity depletion of RB19 anthraquinone dye in water by ozone-based technologies
Water science and technology : a journal of the International Association on Water Pollution Research, 2017
This research investigated the discoloration and mineralization of Reactive Blue 19 (RB19) anthraquinone dye by single ozonation, single UV radiation and ozonation jointed with UV radiation (O3/UV). The problem was approached from two points of view: with the objective of color removal or the mineralization of solution. In each case, the optimum operating conditions were different. Ozonation was the most effective treatment for color removal, while the combined O3/UV treatment was for mineralization. Major intermediates of the dye degradation were identified by gas chromatography/mass spectrometry and a degradation pathway was proposed. In addition, a clear decrease of the toxicity of the dye was achieved at the end of the experiments. The effect of initial dye concentration, pH, ozone dose, and UV radiation on the degradation of the dye and decrease of total organic carbon was investigated, in order to establish the optimal operating conditions to achieve discoloration, mineralizat...
Degradation of Reactive Dyes by Photoactive Hydrogen Peroxide Oxidation with Ultraviolet Radiation
This work aimed at the discoloration of textile wastewater, containing the reactive dye Red Drimarene X-6BN 150, using UV irradiation in presence of hydrogen peroxide. The UV/H 2 O 2 oxidation process is a feasible and efficient alternative for wastewater treatment from recalcitrant compounds such as reactive dyes. The experiments were conducted using a 24 factorial design for evaluation of the influence of pH, H 2 O 2 , urea and NaCl concentrations in the efficiency of the discoloration process. The results were expressed in percentage of color removal from solution by measurement of absorbance. The H 2 O 2 /UV process was effective for reactive dye degradation, reaching 99% dye removal, in specific conditions. The H 2 O 2 concentration presented mainly significant positive influence on the process. Otherwise, the NaCl concentration had a negative effect in all experiments, decreasing the percentage of color removal from reactive dye. The pH and urea concentration didn't influe...
Decolourization of Simulated Dye Wastewater-RB19
Reactive Blue (RB 19), also known as Remazol brilliant blue, is a widely-used colorant in various textile applications. RB 19 is very resistant to chemical oxidation due to its aromatic anthraquinone structure highly stabilized by resonance. Its relatively low fixation efficiency (75-80%) attributed to the competition between the formation of the reactive form (vinyl sulfone) and the hydrolysis reaction, results in its prevalence in textile wastewater discharges. In this study, electro-Fenton (EF) process, a popular advanced oxidation process (AOP) was used to treat RB 19 dye-containing simulated wastewater. The electrochemical reactor (0.5 L) used in all experiments had parallel plate/mesh electrodes coated with metal oxides. Synthetic textile wastewater was prepared by dissolving RB 19 dye (300 ppm) in distilled water. The effects of pH, initial [Fe 2+ ], initial [H 2 O 2 ] and current on RB 19 decolorization efficiency were investigated. Removal of 100 percent RB 19 was achieved at pH 2, 0.71 mM initial [Fe 2+ ], 5 mM initial [H 2 O 2 ] and 1.86 A in 20 minutes. High decolorization efficiencies and absence of sludge during the treatment process render the electro-Fenton process a viable treatment option for dye wastewaters.
Degradation Characteristic of Monoazo, Diazo and Anthraquinone Dye by UV/H2O2 Process
In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H2O2 process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV/H2O2 experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV/H2O2 process is meaningful with respect to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H2O2 photolysis.
Photodegradation of aqueous solution of Mordant red17 (MR17) azo dye in UV/H 2 O 2 , advanced oxidation process was investigated in this study. Results show that MR17 dye decolorization rate was mainly effected by different parameters such as solution pH, H 2 O 2 concentration, initial dye concentrations and presence of different inorganic anions such as NO 3-, Cl-, CO 3 2-ions. The degradation percent of the dye decreased by the presence of inorganic anions in the order of CO 3 2-> Cl-> NO 3-ions. While increase the temperature of the solution medium from 283 to 318K led to increase the decolorization rate of MR17 dye from 0.048 to 0.164 min-1. The low value of the apparent activation energy E a (24.91 kJ mol-1) indicates that decoloriza-tion process of MR17 dye is achieved easily using H 2 O 2 /UV process. This results further proved by presence of 100% decolorization of MR17 dye in about 50 min and about 85.57% mineralization in a 3.0 h photoperiod.
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.