Removal Of Methyl Orange Research Articles

Photocatalytic removal of toxic dyes, liquorice and tetracycline wastewaters by a mesoporous photocatalyst under irradiation of different lamps and sunlight

Simple recyclable K5CoW12O40/TiO2 was synthesized and used to remove methyl orange, rhodamine B, direct red 16 and crystal violet toxic organic dyes, liquorice industrial wastewater and tetracycline (TC) as an antibiotic. Photoactivity of the catalyst was checked out under irradiation of various lamps (such as 18 W fluorescent, 300 W Xenon, LED and IR lamps). The best efficiency was obtained by fluorescent lamp at catalyst loading of 3 g/L, initial pH of 5, initial dye concentration of 5 ppm, complete degradation was achieved after 30 min contact time. Mechanistic investigation showed that·O2 radicals and h+ are majorly responsible for photodegradation in this process. Electrochemical investigation, Nyquist, Bode, Mott-Schottky, Tauc plots and photoluminescence proved that using this photocatalyst delay the electron-hole recombination, increase the lifetime of excited electron, extend light absorption to visible region and improve the light absorption capacity. This photocatalyst work well under winter sunlight. Also 97% and 84% dye removal was obtained for liquorice with 300 and 1000 COD at optimal condition. This catalyst showed similar activity for TC wastewater. Photocatalyst was characterized by FE-SEM, EDX, AFM, FT-IR, XRD, PL, DRS, EIS, BJH and BET.

Efficient Adsorption Removal of an Anionic Azo Dye by Lignocellulosic Waste Material and Sludge Recycling into Combustible Briquettes

In recent years, the removal of dyes has emerged as a significant problem that attracted several researchers. The search for green and eco-friendly adsorbents has been a never-ending task in environmental protection to overcome this issue. Herein, almond shells (AS) were used as an adsorbent to remove methyl orange (MO) from aqueous solutions. The AS was characterized using several techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Adsorption experiments were carried out under different pH, temperature, and AS particle size conditions. Kinetic and isothermal studies revealed that MO adsorption on the AS reached equilibrium at 90 min, following the pseudo-second-order (PSO) kinetic model. The Langmuir adsorption isotherm was found the suitable adsorption model for MO adsorption on AS, showing a maximum adsorption capacity of 15.63 mg/g. Thermodynamic parameters such as the change in standard enthalpy (ΔH°), the change in standard entropy (ΔS°), and the change in standard free energy (ΔG°) indicated that the MO dye adsorption process is non-spontaneous, endothermic, and physical, which was further confirmed from FTIR analysis of AS samples after adsorption. The contaminated sludge was converted into biochar by slow pyrolysis at a temperature of 400 °C for 2 h. Biochar has been exploited for the manufacture of combustible briquettes.

Y-Y microfluidic polymer/salt aqueous two-phase system for optimization of dye extraction: Evaluation of channel geometry

ABSTRACT This study’s main purpose is to investigate the effect of the channel inlet angle on extraction efficiency. Also, the potential of microfluidic polymer/salt aqueous two-phase systems (ATPS) for removing methyl orange (MO) dye has been investigated. The simultaneous influence of independent factors including channel inlet angle, initial dye concentration, flow rate, and pH on the extraction efficiency of MO were investigated. The channel inlet angles of 30°, 60°, and 90° were evaluated. By increasing the inlet angle from 30° to 60°, the extraction efficiency increased from 52.76 to 72.80% at the optimum point. The values obtained at the optimum point were in good agreement with the design equations’ predicted values. At the optimal point, a suitable angle of 60°, an initial concentration of 113.4 mg/L, a flow rate of 1 mL/h, and pH=7 were obtained, which according to the predicted equation, the efficiency reaches 73.27%. In microchannels with a channel inlet angle of 60°, due to having a suitable ratio of top and bottom phases in the outlet of the microchannel and also due to the proper contact of the two phases in the channel inlet (the highest mass transfer section), mass transfer rate and extraction efficiency were increased.

Facile Fabrication of Quaternary Ammonium Salt Modified Cotton Linter by Radiation Grafting and its Effective Removal of Methyl Orange: Batch and Dynamic Flow Mode Studies

Facile Fabrication of Quaternary Ammonium Salt Modified Cotton Linter by Radiation Grafting and its Effective Removal of Methyl Orange: Batch and Dynamic Flow Mode Studies

Kinetic and Equilibrium Studies of Methyl Orange Removal from Aqueous Solution by Adsorption on Activated Rubber Sawdust

This work investigates the removal of the methyl orange by adsorption using rubber saw dust activated carbon (RSDAC). The application of the adsorbent for methyl orange removal was observed to be influenced by the variation in these parameters like adsorbent dose, contact time and pH .The equilibrium data were analysed based on the Langmuir and Freundlich isotherms. Kinetic data were analysed using the pseudo –first order and pseudo –second order models. The maximum adsorption capacity is 111.11mg/g.

Graphitization of flax shive cellulose modified by citric acid: properties of magnetic composites and their dye adsorption capacity

Magnetic composites were synthesized in an inert medium within the temperature range T = 500–1000 °C by one-stage pyrolysis of microcrystalline flax shive cellulose modified by citric acid (MCCA) and homogeneously impregnated with Fe(NO3)3. Catalytic graphitization was studied by the thermogravimetric analysis method. The crystal structure, pore development, morphological structure and surface chemistry of carbon composites were characterized by the N2 adsorption-desorption, XRD, SEM and FTIR methods. The onset temperature of MCCA graphitization was found to be equal to 600 °C. The magnetic carbon materials were tested as adsorbents for removal of anionic methyl orange (MO) and cationic methylene blue (MB) dyes. The highest equilibrium adsorption capacity in MB and MO was found in the magnetic composites synthesized at 700 and 800 °C.

Investigating the photocatalytic role of Ag3PO4 and CdS composites based on CNTs to degrade methyl orange under visible light

AbstractWastewater treatment, if done at a high efficiency and a low price, can be widely used as a strategy to deal with water shortage to a great extent. Advanced oxidation process is one of the best methods of removing colour contaminants from water, and the photocatalytic process, which functions based on semiconductors, is known as an advanced oxidation method. In this research, Ag3PO4/CdS/CNT (Ag/Cd/CN) photocatalyst was prepared using a simple precipitation method with different ratios and Ag/Cd/CN (3:1:15 wt%) nanocomposite showed the best result, so it was finally used to remove methyl orange from water in visible light irradiation. The prepared photocatalyst was detected by fourier transform infrared spectroscopy and X‐ray diffraction spectroscopy analyses. In addition, the morphology of the prepared photocatalyst was investigated and it determined that cadmium sulphide and silver phosphate particles were spread evenly on carbon nanotubes. According to the results of diffuse reflectance spectra analysis, the band gap of the optimum photocatalyst declined from 2.38 eV to 1.97 eV, in comparison with silver phosphate, and the decrease in photoluminescence resulted in the nanocomposite particles being coupled successfully. The distribution of the particles' sizes was analysed by DLS. Furthermore, BET determined mesopores in the prepared nanocomposite. This experiment was designed by Design Expert 7, where the pH parameters, photocatalyst amount, and time were all optimized. As a result, 0.4 g/L of the photocatalyst, prepared in pH = 2.5 and in 60 min, managed to degrade methyl orange (MO) by 98%. The best result was obtained at 45 °C. The prepared photocatalyst showed high stability in dye removal after being used for five cycles. © 2022 Society of Chemical Industry (SCI).

Removal of toxic methyl orange by a cost-free and eco-friendly adsorbent: Mechanism, phytotoxicity, thermodynamics, and kinetics

This article describes the adsorptive removal of acute toxic methyl orange (MO) dye using natural jackfruit leaves powder (JLP) adsorbent without any chemical modification. The adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope equipped with X-ray energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and point of zero charge (pHZPC) Analyses. Under the optimized condition, the highest removal efficiency of MO dye was found to be 78.10%. The adsorption kinetic models ensued pseudo-second order kinetics (R2 > 0.99) and mixed diffusion process (bulk and intra-particle diffusion). The Langmuir model was well fitted (R2 > 0.99) compared to other isotherms and indicated exothermic monolayer adsorption. The study of thermodynamic parameters revealed that the adsorption was spontaneous, physisorption, and exothermic in nature. Phytotoxicity trials on pea (Pisum sativum) seeds showed 0%, 76%, 82%, and 100% germination in experimental MO dye, treated dye, dye-loaded JLP adsorbent, and freshwater respectively, confirmed the nontoxic nature of treated dye as well as dye-loaded JLP adsorbent. Overall, simple preparation, abundant, cost-free, efficient, and environmentally benign nature make JLP a promising adsorbent for the remediation of harmful MO and other dyes contained wastewater.

Enhancing the optical properties of immobilized TiO2/polyaniline bilayer photocatalyst for methyl orange decolorization

Several strategies had been employed to enhance the photocatalytic efficiency of titanium (IV) oxide/polyaniline (TiO2/PANI). In this particular study, ferric (Fe3+) ion was incorporated on the PANI sub-layer backbone instead of TiO2 purposely to improve the removal of methyl orange (MO) dye during the photocatalysis by means of optical properties. The framework of present work involves three stages of preparation which was synthesis of PANI crosslinked with polyvinyl alcohol-glutaraldehyde, doping with Fe3+ ion before coating with TiO2 to form a bilayer photocatalyst. The adhesive and Fe3+ ion solution were added via in-situ and ex-situ of PANI polymerization, respectively. The Fe3+-PANI-polyvinyl alcohol-glutaraldehyde (Fe-PPG) composite solution was then immobilized on the glass support using a facile brushing technique. The presence of Fe3+ ion enhanced the electron-hole separation as well as visible light response of the PPG when coupled with TiO2 in the form of layer by layer assemblage. The properties of light harvesting of the bilayer assemblage were then improved by simple photo-etching under light irradiation which produced more porous TiO2 layer on the sub-layer adsorbent. The thickness increased proportionally with loading in which the best loading of TiO2 on top of Fe-PPG was found to be 1.3 mg cm−2 whereas the photocatalytic-adsorption removal was the highest when MO solution was adjusted to pH 6. The mineralization of MO was also faster when TiO2-Fe-PPG was used to treat the dye as compared to single TiO2 layer. With robust mechanical strength and excellent photocatalytic activity, TiO2/Fe-PPG can possibly find its potential application in the real wastewater treatment plant.

Controllable synthesis of Co–Al layered double hydroxides with different anionic intercalation layers for the efficient removal of methyl orange

ABSTRACT In order to investigate the effect of the types of interlayer anions on the adsorption performance of LDHs, herein, we synthesized three cobalt-aluminum layered double hydroxides (CoAl-LDHs) with different interlayer anions (NO3 –/Cl–/CO3 2–). The experimental results demonstrate that the CoAl-LDH (Cl–) exhibited high adsorption capacity of 1372.1 mg/g at room temperature and the fastest adsorption rate on methyl orange (MO), mainly attributed to the excellent ion exchange capacity and high specific surface area and pore volume. Furthermore, the ion exchange driven by electrostatic interaction, hydrogen bonding, and surface complexation might be the main mechanisms for MO adsorption on CoAl-LDH (Cl–) and CoAl-LDH (NO3 –). However, the MO adsorption on CoAl-LDH (CO3 2–) was strongly pH-dependent and the optimal pH value was about 3.5. Additionally, the supramolecular structure of CoAl-LDHs-MO was formed through electrostatic interaction, hydrogen bonding, and surface complexation between the host hydroxide layers and the guest MO– after adsorption equilibrium. An in-depth understanding of the differences in the adsorption performance of three anion-intercalated CoAl-LDHs will provide opportunities for further improvement of the adsorption capacity and exhibit a bright future for the design and optimization of efficient nano-adsorbents shortly.

Light driven Aspergillus niger-ZnS nanobiohybrids for degradation of methyl orange

Inorganic-microbial hybrid systems have potential to be sustainable, efficient and versatile chemical synthesis platforms by integrating the light-harvesting properties of semiconductors with microbial cells. Here, we demonstrate light-driven photocatalytic semiconducting Aspergillus niger cells-ZnS nanoparticles for enhanced removal of the dye methyl orange. Chemically synthesized ZnS nanoparticles exhibited a zinc blende pattern in X-ray diffraction, had a dimension of 20–90 nm with a band gap (Ebg) of 3.4 eV at 1.83 × 1018 photons/second. Biologically synthesized ZnS nanoparticles of 40–90 nm showed a hexagonal pattern in the X-ray powder diffraction spectra with an Ebg 3.7 eV at 1.68 × 1018 photons/second. At a methyl orange (MO) concentration of 100 mg/L, dosage of 0.5 × 105 mol catalyst and pH 4, a 97.5% and 98% removal efficiency of MO was achieved in 90 min and 60 min for, respectively, chemically and biologically synthesized ZnS nanobiohybrids in the presence of UV-A light. The major degradation products of photocatalysis for chemically synthesized ZnS nanobiohybrids were naphtholate (C10H7O m/z 143) and hydroquinone (C9H5m/z 113). For the biologically synthesized ZnS nanobiohybrids, the degradation products were hydroquinone (C9H5m/z 113) and 2-phenylphenol (C12H10O m/z 170).

Catalytic degradation of MO and MB dyes under solar and UV light irradiation using ZnO fabricated using Syzygium Cumini leaf extract

Abstract Zinc oxide nanoparticles (ZnO NPs) were fabricated using Syzygium cumini leave extract as a reducing and capping agent. The ZnO NPs were characterized using various techniques including scanning electron microscopy, UV-Visible and energy dispersive X-ray (EDX) techniques. The ZnO nanoparticles size was in 0.2–1 µm range and spherical in shape. Photocatalytic efficiency of ZnO NPs for the removal of MB (methylene blue) and MO (methyl orange) was investigated under solar and UV light expire. Photocatalytic efficiency of ZnO NPs was promising, which was found to be high under UV irradiation versus solar light. The ZnO NPs was confirmed as appropriate photocatalytic agent with significant potential for the removal of dye from wastewater.

Removal of methyl orange using combined ZnO/Fe2O3/ZnO-Zn composite coated to the aluminium foil in the presence of simulated solar radiation.

In this paper, the optimal preparative conditions (current density, deposition temperature, calcination temperature) for the original electrochemical synthesis of ZnO-Zn coating on aluminum foil support (ZnAF) were examined and determined the application for the removal of methyl orange (MO). Optimal application conditions for removing MO (volume and concentration of a treated solution) were also determined. In the following, four immobilized ZnO/Fe2O3 photocatalysts with different molar ratios of Zn to Fe (0.42, 0.84, 1.68, and 3.36) were synthesized via the chemical precipitation method on optimized electrochemically synthesized ZnAF support. Characterization studies of synthesized materials included SEM-EDS and Raman scattering analyses. The efficiency of these catalysts for MO removal in the presence/absence of simulated solar radiation (SSR) was investigated. The adsorption isotherms were investigated, and the results show that the adsorption data were best fitted with the Freundlich adsorption isotherm model. Assessment of the thermodynamic parameters showed that although the adsorption process was weakly endothermic over the range of temperatures studied, the relatively high entropy change gave an overall negative change in Gibbs free energy making the processes spontaneous. In the presence of SSR, the optimal molar ratio of Zn to Fe was determined to be 1.68. The possibility of potential reusing the catalyst was examined six times in a row. The possibility for multiple uses of suspension, which is used for immobilization, was also examined. It was also determined that the application of the 1.68Zn/Fe/ZnAF/H2O2/SSR system after the dye removal generates hydrogen at a rate of 186.5μmolg-1 after 6h. Furthermore, in the presence of SSR and using a suspended form of catalyst, the removal efficiency was 1.6 times higher than the efficiency achieved with immobilized ZnO/Fe2O3 catalyst. Using the HPLC method for 1.68Zn/Fe/ZnAF/SSR system, five primary intermediates were found to be formed. The applicability of ZnO/Fe2O3/ZnAF for removal of other dyes was also examined.

Cinnamon nanocellulose as a novel catalyst to remove methyl orange from aqueous solution

In this research, cinnamon nanocellulose was used to remove methyl orange (MO) from aqueous solution. For this purpose, microcellulose was initially prepared by crushing cinnamon and boiling it in an organic solvent. Controlled acid hydrolysis and base treatment of microcellulose led to nanocellulose production. The prepared nanocellulose was characterized by Scanning Electron Microscope (SEM), X-ray Diffraction (XRD),-Fourier Transform Infrared Spectroscopy (FT-IR), Dynamic Light Scattering (DLS) and Brunauer-Emmett-Teller (BET) surface area analysis. The average diameter of nanocellulose was 50 nm. Then, the synthesized nanocellulose was used in the MO decolorization process. The first and final concentrations of MO were measured by a UV–Visible spectrophotometer in the presence of cinnamon, microcellulose and nanocellulose. To obtain high decolorization efficiency, the effects of probable effective parameters such as the amount of nanocellulose, solution temperature, time, and H2O2 addition were also investigated; the parameters were also studied and optimized using Box Behnken Design (BBD) to derive response surface equations. The overall results showed that the highest amount of decolorization was obtained using 50 mg of nanocellulose at the solution temperature of 90 °C in 60 min. The analysis of separated nanocellulose after decolorization using FT-IR, SEM, EDAX approved the morphological and structural stability during the process. As well as the nanocellulose can be used for 6 repeated cycles.

Novel Ternary CuO–CeO2/g-C3N4 Heterogeneous Catalyst for Removing Methyl Orange Dye via Photo-Assisted Fenton-like Reaction

Novel Ternary CuO–CeO2/g-C3N4 Heterogeneous Catalyst for Removing Methyl Orange Dye via Photo-Assisted Fenton-like Reaction

Visible-light-driven double-shell SnIn4S8/TiO2 heterostructure with enhanced photocatalytic activity for MO removal and Cr(VI) cleanup

Construction and design the various heterojunction structures are effective and promising strategies to improve the photocatalytic performances of semiconductors. In this work, a novel visible-light-driven SnIn4S8 nanosheet/TiO2 hollow sphere (SISTOHS) heterojunction with the intimate contact structure was successfully constructed by the facile hydrothermal process. The as-prepared SISTOHS heterostructures displayed outstanding photocatalytic removal activities of methyl orange (MO) and Cr (VI). The optimized sample SISTOHS2 presented the highest photodegradation efficiency of MO (90.08%) and photoreduction efficiency of Cr (VI) (94.44%) within 60 min. Significantly, the rate constants of photodegradation for MO and photoreduction for Cr (VI) over SISTOHS2 were 15.03 and 28.39 folds as high as those of TiO2 hollow spheres, 2.37 and 4.02 folds as high as those of SnIn4S8 nanosheets, respectively. Through the systemic characterizations, the improvement of photocatalytic performance could be not only contributed to the intimate contact double-shell interface introduced a strong interaction between SnIn4S8 and TiO2 to accelerate the separation and migration of charge carriers, but also the increased visible light harvesting ability and abundant reactive sites ensuring the excellent photoactivity. The photocatalytic mechanism of typical type-II heterojunction was discussed in-depth. This work will provide a favorable theoretical and practical experience of designing TiO2 related photocatalyst for wastewater purification.

Fabrication of Zn-Ti layered double oxide nanosheets with ZnO/ZnTiO3 heterojunction for enhanced photocatalytic degradation of MO, RhB and MB

Zn-Ti layered double oxide (LDO) nanosheets were synthesized by a simple co-precipitation-calcination process for the enhanced photocatalytic degradation of methyl orange (MO), rhodamine B (RhB) and methylene blue (MB). ZnTi-LDOs nanosheets present higher photocatalytic efficiency for MO, RhB and MB removal, which is 5.4, 4.4 and 6.7 times of that of Zn-Ti layered double hydroxide (LDH), respectively. The photocatalytic activity of synthesized ZnTi-LDOs is greatly affected by the mole ratio of Zn/Ti, calcination temperature and pH value. It is found that the formation of ZnO/ZnTiO3 heterojunction in ZnTi-LDOs could effectively accelerate the rapid separation of charge carriers, and thus enhance the photocatalytic activity via enlarging the photoresponse range. The possible charge transfer mechanism for photocatalytic degradation of organic dyes by ZnTi-LDOs was proposed based on the active species test and UV–Vis diffuse reflectance spectra. The results of active species trapping experiments showed that ‧OH, ‧O2−, h+, e− all had effect on the degradation of RhB, and ‧OH played a major role. This study provides a new insight for the photocatalytic degradation of organic pollutants from wastewater by ZnTi-LDOs.

Synthesis and Characterization of an α-Fe2O3-Decorated g-C3N4 Heterostructure for the Photocatalytic Removal of MO.

This study describes the preparation of graphitic carbon nitride (g-C3N4), hematite (α-Fe2O3), and their g-C3N4/α-Fe2O3 heterostructure for the photocatalytic removal of methyl orange (MO) under visible light illumination. The facile hydrothermal approach was utilized for the preparation of the nanomaterials. Powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), and Brunauer–Emmett–Teller (BET) were carried out to study the physiochemical and optoelectronic properties of all the synthesized photocatalysts. Based on the X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse reflectance (DRS) results, an energy level diagram vs. SHE was established. The acquired results indicated that the nanocomposite exhibited a type-II heterojunction and degraded the MO dye by 97%. The degradation ability of the nanocomposite was higher than that of pristine g-C3N4 (41%) and α-Fe2O3 (30%) photocatalysts under 300 min of light irradiation. The formation of a type-II heterostructure with desirable band alignment and band edge positions for efficient interfacial charge carrier separation along with a larger specific surface area was collectively responsible for the higher photocatalytic efficiency of the g-C3N4/α-Fe2O3 nanocomposite. The mechanism of the nanocomposite was also studied through results obtained from UV-vis and XPS analyses. A reactive species trapping experiment confirmed the involvement of the superoxide radical anion (O2•−) as the key reactive oxygen species for MO removal. The degradation kinetics were also monitored, and the reaction was observed to be pseudo-first order. Moreover, the sustainability of the photocatalyst was also investigated.

Heterogeneous Photo-Fenton Removal of Methyl Orange Using the Sludge Generated in Dyeing Wastewater as Catalysts

The disposal process of iron-containing sludge often leads to secondary pollution. Pyrolysis of sludge appears to be less polluting than conventional methods. Herein, the heterogeneous photo-Fenton catalysts were prepared using sludge generated in the dyeing wastewater through a simple one-step pyrolysis route. The catalysts were characterized by XRD, FT-IR, XPS, EDS, BET, and SEM. The batch experiments for methyl orange (MO) degradation were performed to evaluate the efficiency and stability of the catalysts. Among the catalysts prepared, FeCN-300 exhibited the best degradation efficiency with 92% removal of the pollutant and good stability, with approximately 90% removal of the pollutant after five cycles. The •OH was identified as the dominant reactive species. This work provides a reasonable resource utilization of iron-containing sludge.

Green approach for fabrication of graphene from polyethylene terephthalate (PET) bottle waste as reactive material for dyes removal from aqueous solution: Batch and continuous study

This study is concerned with the synthesis of graphene from PET waste bottles as raw material and investigates the possibility of using it as an inexpensive and active material for the removal of methylene blue (MB) and methyl orange (MO) from aqueous solution. The synthesis process was achieved in a green way through the manufacture of a stainless steel autoclave that reduces the emission of toxic gases and accelerates the pyrolysis process. The synthesized graphene is characterized by FTIR, SEM, TEM, EDX, XRD, and surface area. Many factors that affect dyes removal percent were studied such as contact time, initial pH of the solution, agitation speed, initial concentration, and sorbent dosage. The sorption isotherm and kinetics study were described using two isotherm models (Langmuir and Freundlich) and two kinetic models (pseudo-first-order and pseudo-second-order), while the column experimental data were fitted with four breakthrough curve models (Thomas-BDST, Bohart–Adams, Yan, and Clark). The experimental results proved that the prepared graphene can be a promising reactive material for the removal of dyes (MB and MO) from aqueous solutions.