Degradation Of Indigo Carmine Research Articles

Photocatalytic degradation of indigo carmine using Nd-doped TiO2-decorated graphene oxide nanocomposites

A series of neodymium-doped titanium dioxide (Nd–TiO2) decorated on graphene oxide (GO) were synthesized by sol–gel method. The structures, morphologies and optical properties of the nanocomposites (Nd–TiO2–GO) were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and ultraviolet–visible spectroscopy. The photocatalytic study of Nd–TiO2–GO nanocomposites was evaluated via the degradation of indigo carmine under simulated solar light. Results demonstrated that the photodegradation efficiency of indigo carmine solutions irradiated by solar simulated light for 3 h with the nanocomposites used as a catalyst reached a level of 92 % (0.6 % Nd). This high photocatalytic degradation of indigo carmine solutions by the Nd–TiO2–GO nanocomposites is ascribed to the spherical nanocrystalline size of TiO2.

Photocatalytic Degradation of Indigo Carmine Dye Using Hydrothermally Synthesized Anatase TiO2 Nanotubes under Ultraviolet Light Emitting Diode Irradiation

Anatase TiO2 nanotubes (ATNT) was synthesised by hydrothermal method using anatase TiO2 nanoparticles (AT) as precursor and calcined at two different temperatures (250 & 450 °C) for 2 h. The AT and synthesized ATNT photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurements, UV-vis diffuse reflectance and Fourier Transform Infra-red spectroscopy techniques for their structural, textural and electronic properties. The photocatalytic degradation of Indigo carmine (IC) dye aqueous solution has carried out using ATNT-250 and ATNT-450 photocatalysts under UVLED irradiation. The kinetic analysis has also revealed that the degradation of IC dye solution follows first order kinetic model. The overall study demonstrates the appropriate band gap of the photocatalysts used and the suitable irradiation source which could accelerate the rate of photocatalytic degradation. The band gap of the synthesised ATNT is not much affected due to the change in morphology from nanoparticle to nanotube. The results demonstrated that the irradiation of UV-LED could be utilised for the degradation of organic dyes

Synthesis of mesoporous TiO2 and its role as a photocatalyst in degradation of indigo carmine dye

A modified sol–gel route without the use of acid or base was used to synthesize mesoporous TiO2 catalyst which was characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force spectroscopy, optical absorption spectroscopy and Brunauer–Emmett–Teller adsorption isotherm technique. The synthesized mesoporous TiO2 is highly crystalline, pure and consisting of very high porosity and surface area 226.25 m2 g−1. The catalyst showed an excellent photocatalytic activity against the degradation of indigo carmine in the presence of visible light. It was found that 50 mL dye solution of 4 × 10−5 M concentration has been completely degraded and decolorized with optimum catalyst dose of 1.5 g/L in 180 min, acidic pH and at 25 ± 1 °C reaction temperature. The reaction kinetic was studied, and it was found that the indigo carmine dye photocatalytic degradation followed pseudo first-order reaction kinetics with rate constant, k of 0.007 min−1. Degradation of dye was confirmed by chemical oxygen demand analysis and UV–Vis spectrophotometry.

Degradation of Indigo Carmine Using Advanced Oxidation Processes: Synergy Effects and Toxicological Study

The physicochemical degradation of Indigo Carmine (IC) dye in aqueous solution was performed using single and combined Advanced Oxidation Processes (AOP’s). Photocatalysis (TiO2-UV), Ozonation (O3) and Sonolysis (SN) were tested either in a standalone methodology or by combination of two simultaneous AOP’s. The dye conversion was followed by both measurements: 1) color removal determined by UV-VIS spectrometry and 2) organic and inorganic load determined by the chemical oxygen demand (COD). A complete and quick color disappearance of model water waste has been obtained by using combination of non-irradiated AOP’s, namely, O3/SN, which contrasts to the combination of irradiated photocatalysis with O3 or sonolysis. Color removal with simultaneous TiO2-UV/SN reached 77% while TiO2-UV/O3 reached 96% at similar reaction time. On the other hand, the standalone O3 yielded the highest color removal (94.4%) in 32 minutes whereas SN reached only 39.2% in 4 hours. The standalone light irradiated TiO2-UV reached 93.3% color re-moval in one hour of reaction time. These results indicated that non-irradiated (SN and O3) enhance synergistic effects that provoke structural changes in dye molecule without reaching total degradation. This is evidenced from FTIR of residuals from reaction mixture in which it has been observed the presence of organic molecules such as aromatics, sulfonic and amines refractory compounds that are mechanisti-cally possible to be found during IC degradation. Also, toxicity tests (MicroTox® Technique) were performed using commercially available bacteria culture before and after IC degradation for each AOP and their combination. Reduction of aqueous dye concentration decreased the level of toxicity of the treated water which is the main target of the AOP’s but the presence of the remaining recalcitrant compounds have also toxic effect.

ZnO and MgO nanoparticles: Synthesis and comparative study on their properties

We report the optical and structural properties of ZnO and MgO nanoparticles. The samples are obtained by a simple method using a new template of hexamethylene tetramine. The optical properties of the samples are studied by UV-visible spectroscopy. Their crystal structure and morphology are studied by XRD and scanning electron microscopy. The absorption spectra of MgO and ZnO show that the optical band gaps are 4.27 eV and 3.02 eV, respectively. In this investigation the photocatalytic degradation of indigo carmine (IC) in water is studied. The effects of some parameters such as pH, amount of catalyst, initial concentration of dye, are examined.

Biodecolorization and Bioremediation of Denim Industrial Wastewater by Adapted Bacterial Consortium Immobilized on Inert Polyurethane Foam (PUF) Matrix: A First Approach with Biobarrier Model.

The present experiments were studied on bioremediation of denim industry wastewater by using polyurethane foam (PU foam) immobilized bacterial cells. About 30 indigenous adapted bacterial strains were isolated from denim textile effluent out of which only four isolates were found to be efficient against crude indigo carmine degradation using broth decolorization method. The selected bacterial strains were identified as Actinomyces sp., (PK07), Pseudomonas sp., (PK18), Stenotrophomonas sp., (PK23) and Staphylococcus sp., (PK28) based on microscopic and biochemical characteristics. The bacterial immobilized cells have the highest number of viable cells (PK07, PK18, PK23 and PK28 appeared to be 1 x 10(8), 1 x 10(9), 1 x 10(6) and 1 x 10(7) CFU/ml respectively) and maximum attachment efficiency of 92% on PU foam. The complete degradation using a consortium of PU foam immobilized cells was achieved at pH 6, 27 degrees C, 100% of substrate concentration and allowed to develop biofilm for one day (1.5% W/V). In SEM analysis, it was found that immobilization of bacterial cells using PUF stably maintained the production of various extracellular enzymes at levels higher than achieved with suspended forms. Finally, isatin and anthranilic acid were found to be degradation products by NMR and TLC. The decolorized dye was not toxic to monkey kidney cell (HBL 100) at a concentration of 50 μl and 95% of cell viability was retained. A mathematical model that describes bacterial transport with biodegradation involves a set of coupled reaction equations with non-standard numerical approach based on the time step scheme.

Effective photocatalytic decolorization of indigo carmine dye in Moroccan natural phosphate–TiO2 aqueous suspensions

Heterogeneous photocatalysis is a significant green technology for application in water purification. In this study, the photocatalytic activity of NP–TiO2 based on Moroccan natural phosphate (NP) doped by titanium dioxide TiO2 was evaluated by photocatalytic decolorization of indigo carmine (IC) dye in aqueous solution as a model pollutant under UV light. The NP–TiO2 catalyst was characterized by XRD, FTIR and surface area. The effect of the calcination temperature of NP–TiO2, catalyst concentration, initial concentration of the IC, initial pH, initial hydrogen peroxide H2O2 concentration and coexisting ions on the photocatalytic decolorization of IC was investigated. The NP–TiO2 showed a significantly higher rate of degradation of IC, when compared to TiO2. After 125min of irradiation using a low intensity of UV-lamp (15W∗3 lamps=45W), 99% of IC solution (20mgL−1) was decolorized with 0.5gL−1 of the NP–TiO2 calcined at 600°C at pH=11. Therefore, this process can be developed as an economically feasible and environmentally friendly method to decolorize or treat dye wastewater using sunlight.

Photocatalytic degradation of organic compounds by PbMoO4 synthesized by a microwave-assisted solvothermal method

The microwave-assisted solvothermal (PbMH) and conventional solvothermal (PbH) synthesis were successfully used to prepare PbMoO4 particles with different morphologies, crystallinity degree and particle size. The material was structurally characterized by X-ray diffraction (XRD), their morphologies were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The textural and optical properties were analyzed by adsorption–desorption N2 isotherms (BET), diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) measurements, respectively. The photocatalytic activity of PbMoO4 particles was evaluated by degradation of indigo carmine (IC), orange G (OG), tetracycline (TC), salicylic acid (SA) and ciprofloxacin (CIP) compounds in aqueous solution under UV–vis light irradiation. The PbMH sample showed the highest photocatalytic activity reaching half-life times (t1/2) of 6, 7, 18, 75 and 125min for TC, CIP, IC, SA and OG. Moreover, PbMoO4 samples were evaluated in the H2 production from aqueous solutions using ethanol as sacrificial agent. The results showed that the PbH sample has the highest photocatalytic activity for hydrogen generation probably attributed to its high crystallinity degree.

Degradation of organic dyes by Si/SiOx core-shell nanowires: Spontaneous generation of superoxides without light irradiation.

Recently, silicon nanowires (SiNWs) have been proven to be highly active in the photocatalysis of dye degradation. However, the unstable hydrogen-terminated surface and the need for constant light irradiation hinder their extensive use. In this work, a stable silica shell was intentionally formed on the surface of SiNWs to produce Si/SiOx core-shell silicon nanowires (S-SiNWs). Light-illuminated or not, S-SiNWs showed almost identical degradation ability for the degradation of indigo carmine (IC) in both conditions, which meant neither hydrogen termination nor light irradiation was a prerequisite for the degradation activity of S-SiNWs. UV/Vis spectroscopy and liquid chromatography/mass spectrometry showed that IC was converted into isatin sulfonic acid in this process. Quenching studies and electron paramagnetic resonance spectroscopy revealed that this bleaching ability was highly dependent on superoxides. A possible mechanism was accordingly suggested. In addition, the recently discovered reductase-like activity of SiNWs can be explained by the superoxides generation.

Indigo carmine degradation in the presence of maltose and ethanol

The majority of important reactions in beer are associated with the action of oxygen during malting and brewing. With respect to oxygen, beer is considered to possess a relatively strong reducing environment. The gradual reduction of oxygen gives rise to reactive oxygen species (ROS) capable of attacking beer components that are important to consumers. Indigo carmine (IC) bleaching was used to prove ROS formation formed by oxidation of beer energy sources such as maltose and ethanol. This paper examines oxygen radical oxidation of organic matter in the presence of the radical initiator potassium peroxodisulphate. A mixture of organic sources of energy such as maltose and ethanol, oxygen, radical initiator and cupric ions generates ROS formation in a broad range of concentrations even at room temperature. ROS irreversibly split blue dye IC into the colourless form and takes part in the radical transformation of organic matter, which is similar to its burning at low temperature or to radical oxidation of reducing agents. Other organic matter can suppress ROS formation and be incorporated into the radical chain of the pathway of its ‘cold burning’. Ethanol inhibited phenylalanine oxidation during its oxidative Maillard reaction. IC bleaching can serve as simple indicator of ROS generation in aerated food. Copyright © 2015 The Institute of Brewing & Distilling

Investigation of pulsed dielectric barrier discharge system on water treatment by liquid droplets in air

The application of non-thermal plasma excited by strong electric fields is becoming a key technology for water treatment because of the efficient generation of oxidants, such as hydroxyl radicals, and no secondary pollution. In this paper, a water treatment system mainly consisting of a pulsed power generator and a dielectric barrier discharge reactor was constructed. The reactor consists of five rows of staggered positive and negative electrodes and separating plates. Wastewater dropped into the discharge area from the tiny holes in the separating plates. Degradation of indigo carmine solution was attempted by this system. The effects of discharge time, discharge voltage, frequency, initial pH value, and H2O2 were studied. The degradation rate came to 100% in 8 minutes at the voltage of 30 kV and frequency of 200 Hz under the initial concentration of 450 mg/L. The energy cost of the degradation of indigo carmine reached 80 g/kWh.

The abatement of indigo carmine using active chlorine electrogenerated on ternary Sb2O5-doped Ti/RuO2-ZrO2 anodes in a filter-press FM01-LC reactor

Dimensionally Stable Anodes (DSA) of Sb2O5-doped Ti/RuO2-ZrO2 are prepared by the Pechini method to perform the degradation of indigo carmine (IC) under conditions similar to textile wastewater effluents. XRD results along with Rietveld refinement reveal that the co-deposited phases on the DSA exhibit a tetragonal crystal structure (P4/mmm) for RuO2 and monoclinic structure (P2/m) for ZrO2. Degradation tests conducted in solutions containing 0.64mM IC and 0.05M NaCl using a filter-press reactor (FM01-LC) show that the degradation rate is faster and more efficient at 200Am−2 with a flow rate of 5Lmin−1, although the energy consumption is moderately higher. Under this condition, the pollutant is efficiently removed, and converted to aliphatic acid compounds of low molecular weight, as indicated by 90 % Chemical Oxygen Demand (COD), 22 % Total Organic Carbon (TOC) elimination, along with an Average Oxidation State (AOS) value equal to 3.0. The energy consumptions revealed that it is feasible to carry out the IC degradation under reasonable operating costs. Topological and Natural Bond Orbital (NBO) analyses are computed using density functional theory (DFT), and combined with experimental results to propose a reaction pathway for IC abatement.

A novel TiO2/autoclaved cellular concrete composite: From a precast building material to a new floating photocatalyst for degradation of organic water contaminants

This paper describes the preparation, characterization and photocatalytic properties of the novel floating composite, consisting of TiO2 supported on autoclaved cellular concrete (ACC). The material was characterized using photoelectron spectroscopy excited by X-rays, scanning electron microscopy (SEM), as well as electronic and atomic absorption spectroscopy. BET (Brunauer, Emmett, Teller) measurements determined the composite surface area. The photocatalytic activity of the novel floating material, upon exposure to UV radiation, was tested for the degradation of indigo carmine, chosen as a model substrate. The performance of three distinct systems, TiO2/ACC/UV, TiO2-P25/UV and UV (photolysis), in the oxidation of indigo carmine was studied utilizing liquid chromatography coupled to mass spectrometry (HPLC–MS). The results indicated that whereas the TiO2-P25/UV and UV systems displayed degradation rates of roughly 60%, TiO2/ACC/UV is by far the most efficient system with removal rates of about 100%, after 350min of exposure. The novel photocatalytic system also yielded higher mineralization rates in comparison to photolysis. We have also studied the photodegradation of diclofenac (a pharmaceutical compound) and atrazine (a pesticide), induced by the same catalyst. Finally, the toxicities of the reaction aliquots were determined against brine shrimp (Artemia salina). Therefore, the novel TiO2/ACC floating composite presents promising potential to act as a photocatalyst to degrade a number of organic contaminants in water.

Enhanced visible-light photocatalytic activity of multi-elements-doped ZrO2 for degradation of indigo carmine

In this study, C,N,S-doped ZrO2 and a series of Eu doped C,N,S-ZrO2 photocatalysts were synthesized by a coprecipitation method using thiourea as the source of C, N and S and Eu(NO3)·6H2O as source of Eu. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy, scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). Indigo carmine (IC) was chosen as a model for organic pollutants and used to evaluate the photocatalytic performance of the photocatalysts under simulated solar light. Commercial ZrO2 was used as a reference material. XRD and Raman results indicated the formation of both tetragonal and monoclinic phase ZrO2 with particle size ranging from 8-30 nm. Multi-element doping had a great influence on the optical responses manifested as red shift in the absorption edge. The highest photocatalytic activity towards IC was observed for the Eu,C,N,S-doped ZrO2 (0.6 mol.% Eu) sample (k=1.09×10−2 min−1). The commercial ZrO2 showed the lowest photodegradation activity (k=5.83×10−4 min−1). The results showed that the control of Eu doping in the C,N,S-ZrO2 was very important in reducing electron-hole recombination. The synergistic effect of Eu, C, N, and S in the ZrO2 matrix led to enhanced utilization of simulated solar energy for the degradation of IC through narrowing of bandgaps.

Palladium-decorated zinc sulfide/reduced graphene oxide nanocomposites for enhanced visible light-driven photodegradation of indigo carmine

The removal of toxic organic pollutants from wastewater using reduced graphene oxide (rGO) based photocatalysts has dominated recent scientific research. As a result numerous nanomaterials have been studied and used for wastewater remediation. ZnS has been widely studied due to its versatile application in photocatalysis. This study presents the synthesis of a series of Pd-decorated ZnS/rGO nanocomposites by a coprecipitation method. The materials were characterized using Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM)–EDS, UV/visible spectrophotometry, and BET surface area analysis. Indigo carmine (IC) dye (20ppm) was chosen as a model for organic pollutants and was used to evaluate the photocatalytic performance of the Pd–ZnS/rGO nanocomposites under simulated solar light with varying concentrations of Pd in the host material. Pd–ZnS/rGO showed significant visible light induced photocatalytic activity towards the degradation of IC. Highest photocatalytic activity was observed for the 1.0% Pd–ZnS/rGO sample (k=2.19×10−2min−1).

Gd,C,N,S Multi-doped ZrO2 for Photocatalytic Degradation of Indigo Carmine Dye from Synthetic Water under Simulated Solar Light

C, N,S-tridoped ZrO2 and Gd, C, N, S-muti-element-doped ZrO2 were synthesized by homogeneous co-precipitation method with different Gd/Zr ratios. The materials were characterized using Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersed X-ray spectroscopy (SEM-EDX) and UV/Visible spectrometry. UV/Vis diffuse reflectance spectroscopy was employed to estimate band gap energies. Indigo carmine (IC) dye (20ppm) was chosen as a model for organic pollutants and was used to evaluate the photocatalytic performance of the photocatalysts under simulated solar light. The Gd-doped C,N,S-ZrO2 showed significant visible light induced photocatalytic activity towards the degradation of IC. Highest photocatalytic activity was observed for the 0.6% Gd-doped C,N,S-ZrO2 sample (k=1.46 x 10-2 min-1). The high photocatalytic performance is due to small crystalline size, strong visible light absorption and narrow band gap.

Solar CPC Pilot Plant Photocatalytic Degradation of Indigo Carmine Dye in Waters and Wastewaters Using Supported-TiO2: Influence of Photodegradation Parameters

The photocatalytic degradation of indigo carmine (IC) dye in the presence of titanium dioxide under different conditions was reported. Several factors which interfere with the photodegradation efficiency as catalyst concentration, pH, initial concentration of dye, presence of inorganic anions, temperature, and the addition of hydrogen peroxide were studied under artificial irradiation with a 125 W mercury vapor lamp. Additionally, the catalyst supported on glass spheres was used for the photocatalytic degradation of the dye present in several types of waters in a CPC solar pilot plant. The photocatalytic products, carboxylic acids, andSO42-andNH4+were followed during IC mineralization. Formate, acetate, and oxalate were detected in real MWWTP secondary effluent. The mineralization efficiency was of 42 and 21% using in suspension and supported TiO2, respectively. In order to evaluate biological effects,Eisenia andreiearthworms were used as a model organism. No significant difference (P>0.05) of weight was observed in the earthworm submitted to different concentrations of IC and its photoproducts. The photocatalytic degradation of IC on TiO2supported on glass spheres suffered strong influence of the water matrix; nevertheless the method has the enormous advantage that it eliminates the need for the final catalyst removal step, reducing therefore the cost of treatment.

Cobalt-doped ZnS-reduced graphene oxide nanocomposite as an advanced photocatalytic material

The removal of toxic organic pollutants from wastewater by graphene-based photocatalysts has dominated recent scientific research. As a result numerous nanomaterials have been studied and used for water remediation. ZnS has been widely studied due to its versatile application in photocatalysis. This study presents the synthesis of Co-doped graphene–ZnS nanocomposite by co-precipitation method. The materials were characterized by X-ray diffraction , Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller surface area analysis. UV/Vis diffuse reflectance spectroscopy was employed to estimate band gap energies. Laboratory experiments with indigo carmine (IC) dye was chosen as a model for organic pollutants and was used to evaluate the photocatalytic performance of Co-doped ZnS–rGO nanocomposite under visible light. The Co-doped ZnS–rGO showed significant visible light induced photocatalytic activity towards the degradation of IC. Highest photocatalytic activity was observed for the 0.3 % Co-doped ZnS–rGO sample (k = 3.1 × 10−2 min−1).

A comparative study on properties of synthesized MgO with different templates

Magnesium oxide powders have been prepared by simple method using different templates as Hexamine (T1), alkylate-hexamine salt (T2) and alkylate–dihexamine salt (T3). The annealed products were systematically investigated by using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and UV–Visible absorption. It was found that the formation of nanoparticle could involved the role of performed “nucleus” and used template to control the growth rate of nucleuses. The results were shown that different templates affect on the size and species of particles. In this study, the crystallite size of the MgO products were in a range from 4 to 7nm. The optical band gap of MgO nanoparticles was in the range 4.27–4.77eV. The morphology of MgO was nanospheres or nanokongelemere-like. In this investigation photocatalytic degradation of Indigo carmine (IC) in water was studied. The effects of some parameters such as pH, amount of catalyst, initial concentration of dye were examined.

Degradation of Indigo Carmine and Reactive Black 5 Dyes with Sb2O5-Doped Ti/RuO2-ZrO2 DSA in a Parallel-Plate Flow Reactor Via Active Chlorine

Wastewater from the textile industry is highly colored and of a complex and variable nature. The substantial amount of dyestuffs used in the dyeing stage of textile manufacturing processes represents an increasing environmental danger due to their refractory nature [1]. The treatment of textile wastewater by conventional methods such as biological and chemical processes or their combination are in common practice but have several drawbacks, e. g. inefficient color removal and/or the formation of toxic by-products [2]. On the other hand, electrochemical oxidation is a very promissory process for refractory pollutants degradation since no chemical reagents are needed and no secondary wastes are formed.In the present study, electrochemical degradation experiments were conducted to degrade a textile dyes namely indigo carmine (IC) and reactive black 5 (RB). A FM01-LC reactor was used to investigate the effect of various operating parameters using a dimensionally stable anode (DSA, Sb2O5-doped Ti/RuO2-ZrO2). The oxidation of IC and RB takes place in the bulk solution with electrolytically generated active chlorine (chlorine, hypochlorite ion and hypochlorous acid). Figure 1 shows the normalized color decay. For the indigo carmine decolorization occurs in 80 min, whereas for the reactive black it takes 2 h. The difference in the time of decolorization is due to the structure of each dye the structure of reactive black 5 is larger than that of indigo carmine.[1] Balcioglu I.A., Arslan I. and Sacan T. Homogenous and heterogenous advances oxidation of two commercial reactive dyes, Environment technology, 22 (2001), pp. 813-822.[2] Rajkumar D., Joo Song B. and Guk Kim J., Electrochemical degradation of Reactive Blue 19 in chloride medium for the treatment of textile dyeing wastewater with identification of intermediate compounds, Dyes and Pigments, 72 (2007), pp. 1-7.