In this study, binary system dye removal by electrocoagulation (EC) process using aluminum electrode was studied in a batch electrochemical reactor. Acid Black 52 and Acid Yellow 220 were used as model dyes. The effect of operating parameters such as conductivity, current density, initial dye concentration and pH on the electrocoagulation process was studied and the electrical energy consumption was calculated. Also the wool dyeing process has been performed and the dye removal from real colored wastewater by the electrocoagulation process has been studied. It was found that the increasing of the current density up to 40A/m2 had increased the dye removal efficiency and the optimum pH for EC process was 5. The increasing of electrolyte concentration from 0 to 8g/L had a negligible effect on the color removal but it has decreased the electrical energy consumption. Data for single and binary systems of dye removal and the results for the synthetic solutions and the real colored wastewater were too close and it can be concluded that the electrocoagulation process is an effective method to remove dyes from colored wastewaters.
No abstract is provided for this article.
Cobalt ferrite (CF) nanoparticle was synthesized and modified by (3-aminopropyl) trimethoxy silane. Polyoxometalate (H3PW12O40) was immobilized on the modified cobalt ferrite (MCF) nanoparticle. The immobilized polyoxometalate onto the modified cobalt ferrite (IPMCF) nanoparticle was used as an environmentally friendly magnetic catalyst for photocatalytic dye degradation. The synthesized IPMCF was characterized using FTIR, SEM, AFM and XRD. Acid Orange 95, Acid Red 18, and Direct Red 81 were used as model dyes. The effect of catalyst dosage, dye concentration and salt on dye degradation was studied. Dye degradation increases by catalyst dosage. The results showed that decolorization followed by zero-order kinetic model.
The photocatalytic degradation of two reactive dyes has been investigated by UV/TiO2/H2O2 using an immobilized TiO2 photocatalytic reactor. Reactive Blue 8 (RB 8) and Reactive Blue 220 (RB 220) textile dyes were used as model compounds. Photocatalytic degradation processes were performed using a 5-L solution containing dyes. The initial concentrations of dyes were 50 mg/L. The radiation source was two 15 W UV-C lamps. A batch mode immersion photocatalytic reactor was utilized. UV–vis and ion chromatography (IC) analyses were employed to obtain the details of the photodegradation of the selected dyes. Colored synthetic waters were completely decolorized in relatively short time after UV irradiation in the presence of various concentrations of hydrogen peroxide. Formate, acetate, oxalate, and glyoxylate anions were detected as dominant aliphatic intermediates where they were further oxidized slowly to CO2. The UV/TiO2/H2O2 process was able to oxidize the dyes with partial mineralization of carbon, nitrogen, and sulfur heteroatoms into CO2, NO− 3, and SO2− 4, respectively. Kinetics analysis indicates that the photocatalytic decolorization rates of the dye can be approximated by a pseudo-first-order model. The UV/TiO2/H2O2 process proved to be capable of decolorization and mineralization of the reactive dyes (RB 8 and RB 220).
In this paper, the use of tamarind hull biosorbent ( Tamarindus indica ) has been investigated to remove cationic dyes from textile eflluent. Basic Violet 6 and Basic Red 18 were used as cationic dye models. The surface characteristics of tamarind hull were investigated using Fourier Transform–infrared and scanning electron microscopy. The influence of process variables such as adsorbent dosage, initial dye concentration and pH were studied. The presence of fuctional groups such as hydroxy and amine groups onto the tamarind hull surface were proved by Fourier Transform–infrared analysis. Data were evaluated for compliance with the Langmuir and Freundlich isotherm models. The results indicated that the data for adsorption of Basic Violet 6 and Basic Red 18 onto tamarind hull fitted well with the Freundlich isotherm model. Also, the adsorption kinetics of Basic Violet 6 and Basic Red 18 on biosorbent was studied. The rates of sorption were found to conform to pseudo‐second‐order kinetics with good correlation. Results indicated that tamarind hull could be used as a biosorbent to remove cationic organics from contaminated watercourses.
No abstract is provided for this article.
No abstract is provided for this article.
In this study, dye removal from synthetic colored wastewater using electrocoagulation process was studied. Acid Red 73 was used as model dye compound. The effects of operational parameters, such as current density, reaction time, initial dye concentration, electrolyte concentration, initial pH, and polyaluminum chloride (as a coagulant), on dye removal were investigated. The cost of wastewater treatment at optimal condition was investigated. The results showed that electrocoagulation process was able to remove 99% dye and 88% chemical oxygen demand. Using polyaluminum chloride as a coagulant had significant impact on improving process efficiency, time, and cost reduction. It can be concluded that electrocoagulation was a very effective and fast method to remove acid dye from colored wastewater.
An immobilized composite photocatalyst, titania (TiO2) nanoparticle/activated carbon (AC), was prepared and its photocatalytic activity on the degradation of textile dyes was tested. AC was prepared using Canola hull. Basic Red 18 (BR18) and Basic Red 46 (BR46) were used as model dyes. Fourier transform infrared (FTIR), wavelength dispersive X-ray spectroscopy (WDX), scanning electron microscopy (SEM), UV–vis spectrophotometry, chemical oxygen demand (COD) and ion chromatography (IC) analyses were employed. The effects of reaction parameters such as weight percent (wt.%) of activated carbon, pH, dye concentration and anions (NO3 −, Cl−, SO4 2−, HCO3 − and CO3 2−) were investigated on dye degradation. Data showed that dyes were decolorized and degraded using novel immobilized composite photocatalyst. Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates where, they were further oxidized slowly to CO2. Nitrate, chloride and sulfate anions were detected as the photocatalytic mineralization products of dyes. Results show that novel immobilized composite photocatalyst with 2wt.% of AC is the most effective novel immobilized composite photocatalyst to degrade of textile dyes.
In this study, the photocatalytic ozonation of Reactive Red 2 (RR2) and Reactive Red 120 (RR120) in aqueous solutions under UV irradiation was investigated using ZnO as a photocatalyst. The effect of operating parameters such as catalyst dosage, pH, initial dye concentration and salt on the decolorization was studied. UV/vis spectrophotometric was used to assess dye decolorization. The results showed that the best pH value and ZnO dosage were 3 and 15 mmol/l, respectively. The dye decolorization enhanced with decreasing initial dye concentration. Sodium sulfate had no significant effect on dye decolorization process but sodium bicarbonate and sodium carbonate increased decolorization time. The results shown that the photocatalytic ozonation process was an effective method to degrade reactive dyes.
Herein, MIL-53(Al)@TiO2 photocatalyst with high photocatalytic performance in the presence of visible light was favorably fabricated using a solvothermal method. Characterization of MIL-53(Al)@TiO2 was carried out by Fourier transform infrared (FTIR), X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the ultraviolet visible diffused reflectance spectra (DRS), and energy-dispersive X-ray (EDX) analyses, and its photocatalytic activity for the degradation of methylene blue (MB) dye was investigated. Compared with MIL-53(Al) and TiO2, the photocatalytic activity of MIL-53(Al)@TiO2 composite under visible light irradiation was improved. This improvement is attributed to the strategy used in composite synthesis without blocked of any hole by TiO2 nanoparticles. The synthesized MIL-53(Al)@TiO2 nanocomposite degraded 95% of the MB in 240 min without any electron acceptor, while the decolorization of dye by MIL-53(Al) and TiO2 was 51% and 79%, respectively. The data also indicated that the dye degradation by MIL-53(Al)@TiO2 followed first-order kinetic with high correlation coefficient (0.9927).
No abstract is provided for this article.
The effect of chain length compatibility on corrosion the inhibition effect of mixed inhibitor systems of cationic gemini surfactant, l,4-butan-bis (dodecyl dimethyl ammonium bromide) (designated as 12-4-12) with nonionic co-surfactants, C7OH (1-heptanol), C12OH (1-dodecanol) and C15OH (1-pentadecanol), on low carbon steel in acid medium was studied using weight loss, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. The data demonstrated that the corrosion rate decreased by increasing surfactant concentration. In addition, less chain length difference causes more compatibility and inhibition on behavior of surfactant and co-surfactant mixture. Inhibition efficiency for C12OH + gemini surfactant was increased compared to the other mixtures explored.
This paper presents a numerical finite volume model for simulation of decolorization and mineralization of dyes by nanophotocatalysis using immobilized titania. Three textile dyes, Remazol Red RB (RR), Remazol Brilliant Blue BB (RBB) and Cibacron Blue TGRE (CB), were used as model compounds. UV–vis, ion chromatography (IC) and chemical oxygen demand (COD) analyses were employed to obtain the details of the photocatalytic degradation of dyes. Numerical finite volume model was used to solve the mathematical equation describing decolorization process. The results showed that the dyes were decolorized and mineralized. The model predictions were compared to those results obtained from experimental tests and close agreement was achieved.
