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An accurate and simple indirect spectrophotometric method has been created for the microdetermination of Methyldopa (MDP) and Dopamine hydrochloride (DA) in acidic media. The method was based on the catalytic oxidation reaction between Orang-G and N-bromosuccinimide in an acidic medium which could be used to create an indirect spectrophotometric method for the micro determination of dopamine hydrochloride and methyldopa in pure form and pharmaceutical formulations. The molar absorptivity and Sandell index of MDP and DA were (4.9×104,3.7×104 ) l.mol-1.cm-1 and (0.0048,0.0051) ng/cm² respectively. The correlation coefficient values were 0.9936,0.9966 with a recovery rate of 99.5% and 99.93%. In addition, the limit of detection (LOD) and limit of quantification (LOQ) were 0.24,0.1788, and 0.727,0.5418 µg\mL. The recommended method was effectively applied for the determination of Dopamine hydrochloride and methyldopa in commercial formulation. No interference was experimentally noticed from common pharmaceutical formulation adjuvants. Statistical evaluation of the results with the standard addition method showed an excellent agreement and showed no significant variance in terms of accuracy and precision. [ABSTRACT FROM AUTHOR]

There has been immense development in the production and use of recyclable materials for dye degradation which are advancing in a wide perspective to minimise the environmental impacts. Therefore, an efficient, eco-friendly, magnetically separable and recyclable catalyst is being reported that has the potential to remove dyes [Tropeolin000, Congo red and Orange G] from wastewater. The catalyst has a backbone containing Zinc, Cobalt and Iron in the ratio Zn0.5Co0.5Fe2O4 with a coating of polyaniline that enhances its dye degradation capability. These synthesised PANi-coated ferrites have been characterised by FTIR, XRD, SEM and EDX techniques, and the photocatalytic activity has been explored using UV–Vis spectrophotometer at ambient conditions. A dye removal efficiency of as high as more than 99.9% has been reported for dye Orange G and above 90% for Tropeolin000. The mechanistic pathway that can be involved in the dye degradation has also been discussed. [ABSTRACT FROM AUTHOR]

The sequestration of orange G (OG) and indigo carmine (IC) dye by utilizing novel incense stick (IS) ash adsorbent was examined in the current study. The dye uptake capacity of the adsorbent was explored through several batch experiments. The efficiency of the adsorbent was studied by different factors viz. adsorbent dose, agitation time, pH, temperature, and dye concentration. The study of the kinetic model described that the pseudo-second-order model was more effective for orange G and indigo carmine dye removal. Adsorption equilibrium was examined by the Langmuir and Freundlich model. The data obtained from the isotherm study for both dyes were well described and fitted to the Langmuir model. The incense stick ash adsorbent material was characterized by SEM, EDAX, BET, and FTIR techniques. The porosity of the adsorbent surface is described by the BET surface area of 6.934 m2/g and the micropore surface area of 4.550 m2/g. At a dye concentration of 50 mg/L and adsorbent dosage of 200 mg, the maximum dye uptake for orange G and indigo carmine was found 26.10 mg/g and 20.53 mg/g, respectively. For OG dye, the values of the thermodynamic parameters ∆H0 and ∆S0 were 40.99 kJ/mol and 0.015 kJ/mol, and for IC dye, 58.81 kJ/mol and 0.191 kJ/mol respectively. Regeneration performance of the used adsorbent was investigated by alkaline treatment. In comparison to the IC dye, the OG dye desorbs at a greater rate of 42.56%. According to this study, using incense stick ash to remove textile dyes would be a cost-effective and environmentally friendly green alternative. [ABSTRACT FROM AUTHOR]

This study explores the valorization of tea leaf waste by extracting polyphenols through reflux extraction, subsequently using them to synthesize zero-valent iron nanoparticles (nZVI). The in situ generated nanoparticles, when combined with fixed amounts of hydrogen peroxide, facilitated the removal of various dyes (methylene blue, methyl orange, and orange G) via a hetero-catalytic Fenton process. The iron nanoparticles were thoroughly characterized by gas adsorption of N2 at 77 K, scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM), FT-IR spectroscopy, X-ray diffraction (XRD), and thermal analysis, including thermogravimetric analysis (TG) and temperature-programmed reduction (TPR). A statistical design of experiments and response surface methodology were employed to analyze the influence of polyphenol, Fe(III), and H2O2 concentrations on dye removal efficiency. The results demonstrated that optimizing the operational conditions could achieve 100% dye removal efficiency. This study highlights the potential of nZVI synthesized through eco-friendly methods as a promising solution for water decontamination involving diverse model dyes, thus contributing to sustainable waste management and environmental protection. [ABSTRACT FROM AUTHOR]

As an azo dye, OG has toxic and harmful effects on ecosystems. Therefore, there is an urgent need to develop a green, environmentally friendly, and efficient catalyst to activate peroxymonosulfate (PMS) for the degradation of OG. In this study, the catalysts MIL-101(Fe) and NH2-MIL-101(Fe) were prepared using a solvothermal method to carry out degradation experiments. They were characterized by means of XRD, SEM, XPS, and FT-IR, and the results showed that the catalysts were successfully prepared. Then, a catalyst/PMS system was constructed, and the effects of different reaction systems, initial pH, temperature, catalyst dosing, PMS concentration, and the anion effect on the degradation of OG were investigated. Under specific conditions (100 mL OG solution with a concentration of 50 mg/L, pH = 7.3, temperature = 25 °C, 1 mL PMS solution with a concentration of 100 mmol/L, and a catalyst dosage of 0.02 g), the degradation of OG with MIL-101(Fe) was only 36.6% within 60 min; as a comparison, NH2-MIL-101(Fe) could reach up to 97.9%, with a reaction constant k value of 0.07245 min−1. The NH2-MIL-101 (Fe)/PMS reaction system was able to achieve efficient degradation of OG at different pH values (pH = 3~9). The degradation mechanism was analyzed using free-radical quenching tests. The free-radical quenching tests showed that SO4•−, •OH, and 1O2 were the main active species during the degradation of OG. [ABSTRACT FROM AUTHOR]

Attempting to reduce issues with dumping and water pollution, bio-based membrane material (MB1000), based on bentonite was elaborated for application in tangential ultrafiltration. For this, morphological properties, textural properties, and chemical structure of the elaborated membrane material were established using Fourier transform infrared spectroscopy, X-ray diffraction, and Brunauer–Emmett–Teller analyses. Water permeability, chemical resistance, as well as point of zero charge of the membrane material were also investigated. The studied membrane material has a mesoporous structure, with a pore size of 7.20 nm and a water permeability of 318.06 L/h.m2.bar. The effect of transmembrane material pressure, pH solution, and concentration on Orange G (OG) and Rhodamine B (RB) dye rejection efficiency was examined and hence optimized. Besides, a mixture of RB and OG dyes was tested for membrane material ultrafiltration in a simultaneous system (RB/OG). Remarkably, an enhancement of the rejection results was noticed for the two dyes (ROG = 94.33%, RRB = 89.38%) resulting from a synergic effect of hydrogen bonding as well as electrostatic interactions generated from functional groups of the molecules dyes. HIGHLIGHTS Elaboration of low-cost and soft bio-based membrane using natural clay.; Membrane ultrafiltration of Orange G (OG) and Rhodamine B (RB).; Membrane ultrafiltration of OG/RB blend.; Synergy in the ultrafiltration of the blend OG/RB and.; Improvement of the rejection percent of OG and RB in the blend compared to the single systems.;

SBA‐15/polypyrrole composite was synthesized by polymerizing pyrrole in the presence of SBA‐15. The samples were characterized using the following techniques: low‐angle XRD, wide‐angle XRD, FTIR, FESEM, TGA, HRTEM, and BET. From the low‐angle XRD analysis, it confirms the formation of a mesoporous hexagonal structure (p6 mm). From the HRTEM image, an orderly arrangement of mesopores is evident. Using adsorption techniques, our objective is to remove sunset yellow, indigo carmine, titan yellow, and orange G dye from aqueous solutions with SBA‐15/polypyrrole composite. The removal efficiency for all the dyes was greater than 90 %. The isotherm was verified to follow the Langmuir isotherm model. The maximum adsorption capacities for sunset yellow, indigo carmine, titan yellow, and Orange G were found to be 78.74 mg/g, 83.33 mg/g, 78.74 mg/g, and 106.38 mg/g, respectively. The adsorption kinetics followed a pseudo‐second‐order model, and the R2 value was greater than 0.99 for all the dyes. The thermodynamic parameters of ΔG°, ΔS°, and ΔH° showed negative values, indicating that the adsorption was spontaneous, decreased entropy, and was exothermic. The recycling of the SBA‐15/polypyrrole composite resulted in a 90 % removal efficiency for three cycles. Therefore, the present adsorbent could be applied to treat industrial effluents that contain these dyes. [ABSTRACT FROM AUTHOR]

In the present study, an azo dye decolourising bacterium, Pseudomonas aeruginosa; JKAK, was isolated and characterised based on morphological, biochemical and 16S rDNA sequence analysis. The strain decolourised 99.12% of 200 mg/L Orange G dye in just 16 h. JKAK also decolourised up to 800 mg/L of the dye by 76.78% in 24 h. The optimum pH and temperature for decolourisation were 8.5 and 40°C, respectively. Also, this strain could decolourise over 90% of the dye in presence of 30 g/L NaCl in less than 20 h. Furthermore, it could decolourise 92.1%, 91.7% and 34.6% of the dye, after 20, 28 and 52 h in the presence of Lead, Zinc and Cobalt ions, respectively. Consortium of JKAK with previously isolated strains of bacteria AK1, AK2 and VKY1 decolourised the dye completely in 12 h. The cell-free extract of JKAK showed azoreductase activity of 0.9 µmoles/min/mg protein. The HPLC and LCMS analysis of the decolourised medium indicated the presence of azo bond breakage products 8-amino-6-hydroxynaphthaline-1,3-disulfonate and aniline. About 42% reduction in phytotoxicity was observed in the decolourised samples. Overall, due to the high decolourising capacity over a wide range of conditions, this strain could be effectively applied for the treatment of textile effluents. [ABSTRACT FROM AUTHOR]

Zero-valent copper (ZVC) activated hydrogen peroxide (H 2 O 2) was widely used to degrade various organic pollutants due to its excellent degradation performance. However, under acidic condition, the low efficiency inhibited the pollutants degradation efficiency. In this study, the supplement of ferric ion (Fe(III)) markedly improved the orange G degradation in the ZVC/H 2 O 2 system. Various reactive species such as hydroxyl radical (•OH) and Fe(Ⅳ) were identified, besides the contribution rate of the reactive species could be adjusted by changing the reaction parameters. During the degradation of orange G, ZVC furnished Cu(I) by hydrogen erosion and the reaction with O 2 and H 2 O 2 , and then ZVC and Cu(I) boosted Fe(III)/Fe(II) circulation, part of Fe(II) and Cu(I) activated H 2 O 2 to generate •OH, another part of Fe(II) reacted with H 2 O 2 to generate Fe(Ⅳ), resulting in orange G removal. Common coexisting substances in natural water bodies such as nitrate ion and sulfate ion hardly influence the removal of orange G, while Cl- notably enhanced the removal of orange G, and humic acid markedly suppressed the decoloration of orange G. Orange G removal by the ZVC/Fe(III)/H 2 O 2 system showed outstanding performance in actual water samples. In addition, the total dissolved copper complied with the II-level environmental quality criteria after alkali precipitation. All the above facts bespoke the ZVC/Fe(III)/H 2 O 2 system had substantial application prospects. [Display omitted] [ABSTRACT FROM AUTHOR]

Azo dyes have been found in wastewater from textile industries. These compounds continuously persist in the environment for long periods of time and may be toxic for living beings. An alternative treatment for dye removal that has proven to be effective is aerobic treatment with fungi. In this study, Aspergillus niger was investigated as a mechanism to remove orange G (OG). Removal of 200 mg/L of OG by A. niger biomass was carried out in solid and liquid medium, which showed a positive correlation between A. niger growth and dye removal. In liquid media what was proved is that the efficiency of OG removal by A. niger depends on its concentration; at 200 mg/L of OG remove by degradation and at 400 mg/L by processes as sorption and degradation. During OG removal, the generation of organic acids by A. niger was modified compared to constitutive generation, one of the modifications was the increase of gluconic acid production and the decrease of acids involved in the Krebs cycle, as well as the null detection of oxalic acid. The monitoring of organic acids by high-performance liquid chromatography (HPLC) was important because some of them have been linked to dye removal. [ABSTRACT FROM AUTHOR]

In this study, low concentration of ferrous ions (Fe2+) was added into natural molybdenite (MDN) activated peroxymonosulfate (PMS) process to degrade a typical azo dye, orange G (OG). It was found that the addition of Fe2+ promoted OG degradation and simultaneously reduced the leaching of toxic Mo ions significantly. Further, the utilization efficiency of MDN was improved immensely, which was estimated from reuse experiment. MDN mainly acted as the reductant to promote cycling of Fe3+/Fe2+ redox couple through reducible sulfur and Mo(IV) on its surface. Sulfate radicals (SO4•-), hydroxyl radical (•OH) and singlet oxygen (1O2) were verified as the main reactive oxygen species responsible for OG degradation by scavenging tests and electron paramagnetic resonance. Some experiment parameters, such as MDN dosage, Fe2+ concentration, PMS concentration, initial solution pH and coexisting anion, all affected OG degradation efficiency. In a word, this work provides a new method of enhancing PMS activation by MDN using low concentration of Fe2+ for degradation of organic pollutants in water. HIGHLIGHTS MDN was applied as an efficient co-catalyst for permonosulfate activation.; The sulfur element on MDN surface was able to reduce generated Fe3+.; , , and were responsible for the removal of OG in MDN/Fe2+/PMS system.; The Fe2+ was demonstrated to promote the reusability of MDN.;

A coupling method of water surface plasma (WSP) with β-Bi2O3/CaFe2O4 composite was applied to promote the elimination of aqueous Orange G (OG). The morphology, structures, crystal form and chemical bonding state of the prepared β-Bi2O3/CaFe2O4 composite were characterized via SEM, TEM, EDS-mapping, XRD, FT-IR and XPS. The results showed that the addition of composites significantly enhanced the degradation and kinetic constant of OG. The degradation efficiency of the combined system containing 8.0 wt% β-Bi2O3/CaFe2O4 composite was 28.9% higher compared to the sole WSP for OG degradation. The synergistic factor (2.387) demonstrated that the combined system was able to establish a synergistic effect. The effect including peak voltage, air flow rate, initial conductivity and initial concentration of solution on OG removal was inspected. The active species trapping experiments demonstrated ·OH, h+, ·O2− and high-energy electrons devoted to OG removal in the combined system. O3 and H2O2 were also involved in the OG removal in the combined system. Three-dimensional fluorescence spectroscopy and liquid chromatography-mass spectrometry were tested to investigate the mechanism of OG degradation. Finally, the combined system in the present study was compared with other competitive technologies for the degradation of OG in the literature. [ABSTRACT FROM AUTHOR]

In the present study, the degradation of an azo dye Orange G (OG) by the UV/TiO2/periodate (IO4-) process has been investigated. OG was totally disappears within 10 min by the UV/TiO2/IO4-compared to UV alone, UV/TiO2 or UV/IO4-. A synergistic effect has been obtained when combining the UV/TiO2 and the UV/IO4-systems, resulting in positive interactions between both processes. Experiments conducted with specific hydroxyl radical scavengers, show that despite the inhibition effect observed, complete degradation has been achieved beyond 10 min, demonstrating that the degradation is not only initiated by hydroxyl radical, but also by other reactive entities; the involvement of iodate radical is confirmed with the use of chromium species as a competitor with periodate ions for the photogenerated electron at the conduction band. The operating parameters influencing the degradation process such as initial dye concentration, initial periodate concentration, light intensity/wavelength and initial pH solution have been explored. The presence of inorganic ions such as chloride, bromide, sulphate, carbonate and bicarbonate ions in the irradiated solution show reverse effects depending on the concentration used. The OG degradation in different water matrices is found to be sensitive to the presence of different species and their nature. Chemical oxygen demand (COD) has been partially removed after 10 min of treatment, and then this COD abatement stabilized, indicating the strength of the by-products from dye degradation by the UV/TiO2/IO4- system during the treatment time. The electrical energy consumption is estimated at 2.21kWhm3/Order. The results obtained indicate that the UV/TiO2/IO4- process could be used as a hybrid process to the treatment of dye contaminated water. [ABSTRACT FROM AUTHOR]

Wastewater containing an azo dye Orange G (OG) causes massive environmental pollution, thus it is critical to develop a highly effective, environmental-friendly, and reusable catalyst in peroxymonosulfate (PMS) activation for OG degradation. In this work, we successfully applied a magnetic MnFe 2 O 4 /α-MnO 2 hybrid fabricated by a simple hydrothermal method for OG removal in water. The characteristics of the hybrid were investigated by X-ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller method, vibrating sample magnetometry, electron paramagnetic resonance, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The effects of operational parameters (i.e., catalytic system, catalytic dose, solution pH, and temperature) were investigated. The results exhibited that 96.8% of OG degradation was obtained with MnFe 2 O 4 /α-MnO 2 (1:9)/PMS system in 30 min regardless of solution pH changes. Furthermore, the possible reaction mechanism of the coupling system was proposed, and the degradation intermediates of OG were identified by mass spectroscopy. The radical quenching experiments and EPR tests demonstrated that SO 4 •̶, O 2 •̶, and 1O 2 were the primary reactive oxygen species responsible for the OG degradation. The hybrid also displayed unusual stability with less than 30% loss in the OG removal after four sequential cycles. Overall, magnetic MnFe 2 O 4 /α-MnO 2 hybrid could be used as a high potential activator of PMS to remove orange G and maybe other dyes from wastewater. [Display omitted]. [ABSTRACT FROM AUTHOR]

This report focusses on the modification of physical structure and chemical properties of a bentonite clay from the Hammam Boughrara region of the Maghnia district in western Algeria to maximize its adsorption capacity. The purified bentonite clay (called B) was modified, either by acid activation with 1M sulfuric acid (B-Act), or by intercalation with the cationic surfactant cetytrimethyl ammonium bromide (CTAB), applying a cation exchange capacity (CEC) of 100% (called B-CTAB). Modification of B was also introduced by combining these two steps consecutively, i.e., at first acid activation of B, followed by intercalation with CTAB (B-Act-CTAB). The B-Act-CTAB was obtained by H2SO4 (1M) acid activation, followed by co-adsorption of CTAB with 100% and 300% of the CEC of B-Act as precursor. In particular, a strong increase of surface area and pore volume of the modified bentonites was observed for B-Act (469.83 m²/g and 0.401 cm3g−1), B-Act-CTAB100 (267.72 m²/g and 0.316 cm3 g−1) and B-Act-CTAB300 (111.15 m²/g and 0.171 cm3g−1), compared to B (31.79 m²/g and 0.074 cm3 g−1) and B-CTAB (3.79 m²/g and 0.034 cm3 g−1), respectively. The bentonite-based adsorbents were then used to evaluate the removal efficiency of an organic molecule, the azo dye Orange G (OG), as a model for a Persistent Organic Pollutant. Freundlich, Langmuir and Sips (Langmuir–Freundlich) models were applied to analyze equilibrium isotherms, showing a good correlation between experimental data and the Freundlich model. A good agreement was obtained between experimentally obtained kinetic adsorption data and the pseudo-second-order model, allowing to evaluate rate constants. B-Act-CTAB300 can be applied as a low-cost material for removal of azo dyes, since its adsorption capacity towards OG (102.80 mg/g) exceeds largely that of B-CTAB (31.49 mg/g) and B-Act-CTAB100 (12.77 mg/g). [ABSTRACT FROM AUTHOR]

In this work, the usability of magnetic gelatin nanofiber (MGNF) for anionic dye removal was investigated in the aqueous solution. For this aim, the MGNF was prepared using the electrospinning technique with the addition of Fe3O4 nanopowders. After the characterization of MGNF with Fourier transform infrared spectroscopy, swelling test, scanning electron microscope, and energy-dispersive X-ray analysis, the adsorption performance of MGNF against the dye molecule, Orange G, was examined by changing the pH of the media, the dye concentration, and the ionic strength. The experimental results showed that the maximum adsorbed amount of Orange G was found as 15.6 mg/g at pH 3 value and the Orange G adsorption behavior was endothermic, physical, and suited to the Langmuir adsorption isotherm model. The adsorption kinetic of Orange G was evaluated with the pseudo-first-order, the pseudo-second-order, and the Elovich kinetic models and the pseudo-second-order model results fitted the experimental findings as compared to the other models. The affordable magnetic adsorbent was capable of maintaining its stability after five consecutive adsorption, desorption, and regeneration cycles without significant loss of adsorption capacity. [ABSTRACT FROM AUTHOR]

Thermal modification of rice husk in open air environment was carried out by burning of rice husk, followed by a heat action in tube furnace at 973 Kfor one hour. The material obtained was whitish in colour and termed as rice husk ash (RHA), which was applied to adsorbed the Orange G-dye from aqueous medium. The adsorption process was studied in various experimental conditions that could greatly affect the adsorption process. The optimum conditions for the maximum adsorption of dye, were investigated as; pH 4, temperature 303 Kand 80mg/L of initial dye concentration containing 2g/L of the adsorbent concentration. At optimum conditions the dye removal was investigated as 57.6% with adsorption capacity 23.05 mg/g. Thermodynamic study indicated that the adsorption process is exothermic and spontaneous. Kinetic data for the adsorption of Orange-G on the RHA-adsorbent, best followed the pseudo-S second order kinetic model, whereas equilibrium experimental data is fit to Langmuir-model, suggested that adsorption of OG on RHA is a chemical adsorption. [ABSTRACT FROM AUTHOR]

Dye effluent damaged the water environment and human health with its massive discharge. In order to eliminate dye from the water environment, a variety of adsorbents were used to investigate dye removal. Graphene oxide (GO) attracted extensive attention due to its excellent surface property in the degradation of dye wastewater. Modified GO with multifunctional groups helped to improve adsorption performance. 3-Aminopropyltriethoxysilane modified GO (AS-GO) was fabricated for the removal of Orange G (OG) in this study. The results showed that AS-GO had an excellent adsorption ability of OG. During the reaction process, the maximum adsorptive capacity of OG was up to 576.6 mg/g at T = 313 K and pH = 3 with the initial OG concentration of 100 mg/L and the initial adsorbent dose of 2.5 g/L. The adsorption kinetic process of AS-GO conformed to the pseudo-second-order and Langmuir models. The spontaneous and endothermic adsorption of OG occurred in the adsorption process. The main adsorption mechanisms were electrostatic, π–π and hydrogen bonding interactions in the reaction process. After four cycles of AS-GO, it maintained high removal efficiency owing to its remarkable stability. The scheme of GO modified with AS could hinder the agglomeration of GO and provide more active sites, which would further enhance the adsorption properties and expand its application in water purification. [ABSTRACT FROM AUTHOR]

The extracellular insoluble deposits of highly ordered cross-β-structure-containing amyloid fibrils form the pathological basis for protein misfolding diseases. As amyloid fibrils are cytotoxic, inhibition of the process is a therapeutic strategy. Several small molecules have been identified and used as fibrillation inhibitors in the recent past. In this work, we investigate the effect of Orange G on insulin amyloid formation using fluorescence-based assays and negative-stain electron microscopy (EM). We show that Orange G effectively attenuates nucleation, thereby inhibiting amyloid fibrillation in a dose-dependent manner. Fluorescence quenching titrations of Orange G showed a reasonably strong binding affinity to native insulin. Binding isotherm measurements revealed the binding of Orange G to pre-formed insulin fibrils too, indicating that Orange G likely binds and stabilizes the mature fibrils and prevents the release of toxic oligomers which could be potential nuclei or templates for further fibrillation. Molecular docking of Orange G with native insulin and amyloid-like peptide structures were also carried out to analyse the contributing interactions and binding free energy. The findings of our study emphasize the use of Orange G as a molecular probe to identify and design inhibitors of amyloid fibrillation and to investigate the structural and toxic mechanisms underlying amyloid formation. • Orange G binds to human insulin with a reasonably strong affinity. • It inhibits insulin amyloid fibrillation in a concentration-dependent manner. • This is achieved by interacting with early species in the fibrillation process. • It can be used as a probe to identify and design inhibitors of amyloid toxicity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Regenerative, recyclable, and stable AgCl-SnO 2 nanocomposite. • 98 % photocatalytic azo-dye degradation observed within 60 min of irradiation. • Sacrificial agent EDTA degrades 99 % within 30 min of exposure. • Degradation of azo-dye into intermediates with reduced toxicity. • Significant potential as antimicrobial agent against E. coli. Herein, AgCl-SnO 2 nanocomposite (NC) fabricated through a facile hydrothermal method exhibit substantial potential as an efficient and economical photocatalyst and bactericidal agent. The formation of spherical AgCl-SnO 2 NC was confirmed through PXRD and SEM, with an average crystalline size of 12 nm. DR spectra and Kubelka-Munk function were used to determine the band gaps of AgCl (3.10 eV) and SnO 2 (3.48 eV). The synthesized NC achieve successful photocatalytic degradation (98 %) of orange-G (OG) dye within 60 min. The NC's potential was also elucidated by investigating the role of sacrificial reagents. Formation of •OH free radicals is confirmed from photoluminescence studies using terephthalic acid. The effective degradation of OG dye has been substantiated, resulting in the generation of numerous intermediate products with reduced toxicity, such as substituted phenols and aromatic dicarboxylic compounds. Furthermore, the NC demonstrated excellent efficiency even after six consecutive cycles, indicating its stability, regenerative property, and recyclability. The NC also exhibits significant antimicrobial activity against Escherichia coli. [ABSTRACT FROM AUTHOR]

In this study, tungsten trioxide/titanium dioxide (WO3–TiO2) nanohybrid structures were prepared using a facile hydrothermal method. The nanosheets-like morphology was achieved for the prepared WO3–TiO2 nanohybrid that were confirmed by scanning electron microscopy. Provided X-ray photoelectron spectroscopy results also confirm the element existence and surface composition of the nanohybrid structure. The optical properties of the WO3–TiO2 nanohybrid were verified using UV–Visible diffuse reflectance spectroscopy (UV–Vis DRS) and photoluminescence spectroscopy. The UV–Vis DRS results indicated that the absorption edge for the WO3–TiO2 nanohybrid found a red shift towards the visible region due to the reduced bandgap (2.83 eV). The photocatalytic activity of the as-prepared WO3–TiO2 nanohybrid was evaluated by the photocatalytic degradation of Orange G dye in wastewaters under visible light. 94% Orange G dye was degraded in 210 min at neutral pH in the presence of WO3–TiO2 nanohybrid, which indicates the enhanced photocatalytic activity. The photo-luminescence technique has also confirmed the formation of –OH radicals during photodegradation by utilizing terephthalic acid as a probe molecule. These results indicate that the prepared nanohybrid material is a simple, low-cost, and efficient photocatalyst for the degradation of pollutants in wastewater treatment applications. [ABSTRACT FROM AUTHOR]

Bimetallic nanoparticles comprised of iron and nickel were synthesized, characterized, and evaluated to optimize the ideal metal ratio for azo dye removal from water systems. Results show that changing the molar ratio of nickel to iron caused different removal rates, as well as the extent of overall elimination of azo dye from water. Lower molar ratios, from Ni1Fe10 to Ni2.5Fe10, exhibited a higher removal efficiency of 80-99%. Higher concentrations of Ni in the catalyst, from Ni3Fe10 to Ni5Fe10, resulted in 70-90% removal. The lower molar ratios of Ni exhibited a consistent removal rate of 0.11 g/L/min, while the higher molar ratios of Ni displayed varying removal rates of 0.1-0.05 g/L/min. A second order kinetic model was fit to the first twenty minutes of the reaction for all nickel to iron compositions, where there is a decrease in rate constant with an increase in molar ratio. During the last forty minutes of reaction, azo dye removal fit a zero order kinetic model. All as-synthesized nanoparticle samples were found to be structurally disordered based on the lack of distinct peaks in XRD spectra. Post-reaction samples were found to have Fe2O3 and FeOOH cubic peaks.

In the current study, Bismuth molybdate was synthesized using simple co-precipitation procedure, and their characterization was carried out by various methods such as FT-IR, SEM, and P-XRD. Furthermore, the photocatalytic degradation of Orange G (ORG) dye using synthesized catalyst under visible light irradiation was studied. Response surface Method was used for the optimization of process variables and degradation kinetics evaluated by modeling of experimental data. Based on the experimental design outcomes, the first-order model was proven as a practical correlation between selected factors and response. Further ANOVA analysis has revealed that only two out of six factors have a significant effect on ORG degradation, however ORG concentration and irradiation time indicated the significant effects sequentially. Maximum ORG degradation of approximately 96% was achieved by keeping process parameters in range, such as 1 g L−1 loading of catalyst, 50 mg L−1 concentration of ORG, 1.4 mol L−1 concentration of H2O2 at pH 7 and a temperature of 30 °C. Kinetics of ORG degradation followed the pseudo first order, and almost complete degradation was achieved within 8 h. The effectiveness of the Bi2MoO6/H2O2 photo-Fenton system in degradation reactions is due to the higher number of photo-generated e- available on the catalyst surface as a result of their ability to inhibit recombination of e- and h+ pair. [ABSTRACT FROM AUTHOR]

Iron-coated expanded perlite (Fe-EP) was prepared as a heterogeneous catalyst for activating persulfate (PS) to degrade Orange G (OG) under ultrasonic irradiation (US). The expanded perlite (EP) and Fe-expanded perlite (Fe-EP) catalyst were characterized by several techniques. X-ray diffraction analysis showed that the Fe-EP catalyst mainly consists of SiO2, Fe2O3, and Al2O3 crystallites. The BJH average pore diameter of the prepared catalyst is found to be 15.39 nm. The catalytic performance of the Fe-EP was tested by the discoloration of OG in US/Fe-EP/PS system. The effect of factors influencing the percentage of degradation was analyzed. At optimal conditions (1.2 mmol/L of S2O82−, 40 mg/L of initial OG concentration, and pH = 5), the treatment efficiency of OG attains 94% after 40 min. Also, the effects of the addition of iron (III) and H2O2 on the degradation efficiency were determined. The reaction process of OG discoloration was followed by UV–Vis technique. The negligible iron leaching and the possibility of reuse indicated satisfactory stability of prepared catalyst. Phytotoxicity tests towards the broad bean plant (Vicia faba L.) confirmed that the OG dye is phytotoxic. [ABSTRACT FROM AUTHOR]

Mesoporous MCM-41 material was synthesized and it was successfully incorporated with Vanadium at room temperature by simple co-precipitation method. Higher portion of V+5 was noticed in the framework of V-MCM-41 material without disturbing the mesoporosity. The materials were characterized by X-ray diffraction (XRD), Nitrogen adsorption-desorption studies (BET method, SBET), scanning electron microscope coupled with electron dispersive x-ray spectroscopy (SEM-EDAX), and UV-Vis diffused reflectance (UV-Vis DRS) techniques. The catalytic activity of the synthesized materials were investigated toward the removal of orange G dye (OG) and was observed that the VMCM-41 has superior catalytic activity in the presence of hydrogen peroxide. [ABSTRACT FROM AUTHOR]

Ni, Ce, and Ta modified Ti/SnO2–Sb2O5–RuO2 anodes were first prepared by thermal decomposition strategy and applied for Orange G degradation to explore the effect of Ni, Ce, and Ta modification on electrocatalytic property. The Ta modified anode showed the highest ·OH generation capability and the lowest charge transfer resistance among all samples, conducive to electrocatalytic degradation of Orange G. Besides, the Ta modified anode shows more cracks than Ni and Ce modified anodes, which is expected to create more specific surface areas and more exposed active sites for Orange G degradation. The degradation efficiency and the total organic carbon (TOC) removal rate increased in the order Ru < Ru–Ni < Ru–Ce < Ru–Ta, with Ru–Ta showing the highest degradation efficiency of 98.6% and 44.2%, much higher than 79.6% and 27.5% of Ru, respectively. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of the Acid Orange 10 was carried out in a static reactor used for direct photolysis under polychromatic external lighting. Acid Orange 10 (Orange G: OG), is used in silk, wool products and dyeing. It is a recalcitrant dye, which resist to oxidation and thermal degradation, and persists in the aquatic environment. The photodegradation is one of the most studied processes over the last two decades and its large-scale application has grown steadily. As we will see below, the entity that absorbs light is a semiconductor characterized by a narrow forbidden band. The photodegradation of OG onto TiO2 material has been investigated at batch conditions. The effects of contact time (0–60 min), initial pH (3–11), adsorbent dose (0.1–1 g/L), and OG concentration (10–40 mg/L) on the OG oxidation by TiO2 have been studied. High light intensity increases the degradation efficiency. The experimental results have shown that the photocatalytic efficiency is proportional to the dose of catalyst, which above a threshold value becomes almost constant and depends on the pH. The adsorption is an important step controlling the apparent kinetic constant of the photocatalysis. The photodegradation rate was favored for high OG concentrations in agreement with the Langmuir–Hinshelwood model with constants Kr and Kad are respectively 0.4780 L mg/min and 0.7823 L/g. The degradation rates are pH and temperature dependent with a high degradation at high temperatures. TiO2 has a better activity for the OG degradation, compared to many catalysts available in the literature. [ABSTRACT FROM AUTHOR]

This report focusses on the modification of physical structure and chemical properties of a bentonite clay from the Hammam Boughrara region of the Maghnia district in western Algeria to maximize its adsorption capacity. The purified bentonite clay (called B) was modified, either by acid activation with 1M sulfuric acid (B-Act), or by intercalation with the cationic surfactant cetytrimethyl ammonium bromide (CTAB), applying a cation exchange capacity (CEC) of 100% (called B-CTAB). Modification of B was also introduced by combining these two steps consecutively, i.e., at first acid activation of B, followed by intercalation with CTAB (B-Act-CTAB). The B-Act-CTAB was obtained by H2SO4 (1M) acid activation, followed by co-adsorption of CTAB with 100% and 300% of the CEC of B-Act as precursor. In particular, a strong increase of surface area and pore volume of the modified bentonites was observed for B-Act (469.83 m²/g and 0.401 cm3g−1), B-Act-CTAB100 (267.72 m²/g and 0.316 cm3 g−1) and B-Act-CTAB300 (111.15 m²/g and 0.171 cm3g−1), compared to B (31.79 m²/g and 0.074 cm3 g−1) and B-CTAB (3.79 m²/g and 0.034 cm3 g−1), respectively. The bentonite-based adsorbents were then used to evaluate the removal efficiency of an organic molecule, the azo dye Orange G (OG), as a model for a Persistent Organic Pollutant. Freundlich, Langmuir and Sips (Langmuir–Freundlich) models were applied to analyze equilibrium isotherms, showing a good correlation between experimental data and the Freundlich model. A good agreement was obtained between experimentally obtained kinetic adsorption data and the pseudo-second-order model, allowing to evaluate rate constants. B-Act-CTAB300 can be applied as a low-cost material for removal of azo dyes, since its adsorption capacity towards OG (102.80 mg/g) exceeds largely that of B-CTAB (31.49 mg/g) and B-Act-CTAB100 (12.77 mg/g).

In the treatment of water and wastewater, more emphasis is paid to the advanced oxidation process (AOP) based on (S2O82-) radicals. In this work, the degradation of a toxic dye (Orange G) using the heat-activated persulfate was examined Plackett and Burman designs experiments were used to investigate the effects of several parameters on the oxidation of the OG by K2S2O8, including persulfate concentration K2S2O8, the initial dye concentration, the reaction time, the initial solution pH, and temperature. The screening results identify three more influential factors that are subsequently studied by the response surface methodology employing Box--Behnken design to determine optimal conditions for maximal degradation effectiveness. The estimated values agreed with the experimental data, with a coefficient of the determination R² = 0.9429. The forecasted data revealed that with a concentration of Orange G 2 mg/L, a concentration of persulfates of 27.018 mM and a temperature of 45.5°C, a maximum orange degradation of 100% could be attained. The efficacy and the benefits of the advanced oxidation method using heat-activated persulfate for technological and industrial applications for the degradation of the organic pollutants have been well-proven in this work. [ABSTRACT FROM AUTHOR]

The defiance of this study was to explore the potential of alginate/MIL-101 beads containing Fe3O4 nanoparticles as a catalyst for the reduction of dyes. The Fe3O4@MIL-101 magnetic composite was obtained by the mechanical method and then encapsulated using calcium alginate (CA) as a crosslinked matrix. The Fe3O4(X)@MIL-101/CA composites beads at different content (X) of Fe3O4 nanoparticles were evaluated for the catalytic reduction of methylene blue (MB) and orange G (OG). The aerogel beads have completed the MB dye reduction after 7 min with a rate constant of 0.962 min–1. This strong activity is assigned to the synergistic effect between Cr containing MIL-101 the Fe3O4 particles and the hydrides formed on the catalyst surface. The obtained optimal conditions of MB dye reduction were used for the reduction of OG dye in simple and binary system.The best catalyst M(1)@MIL-101/CA showed a high affinity via MB dye in a binary system. Then was easily recovered by an external magnetic field and reused for 4 cycles. On the other hand, the time of the catalytic activity clearly increased in its 4th reuse in the reduction of MB dye but did not affect the efficiency of catalytic reduction. [ABSTRACT FROM AUTHOR]

The role of weak magnetic field (WMF) on the degradation of a common textile azo-dye, orange G (OG), by magnetic Fenton system was investigated in detail. The results showed that the presence of WMF can provide better performance of the Fe3O4/H2O2 system for OG degradation. The optimized reaction conditions were contained at 1 mM Fe3O4 as Fe, 20 mT of magnetic field intensity, 20 mM H2O2, and initial pH of 3.0. The removal efficiency of OG by Fe3O4/H2O2 coupling with WMF increased largely from 56.3 to 82.3% compared with Fe3O4/H2O2 process. Both the electron paramagnetic resonance (EPR) analysis and the quenching effect of tert-butyl alcohol (TBA) confirmed that hydroxyl radical (•OH) was the primary reactive oxygen species in WMF-Fe3O4/H2O2 system. The improving effect of WMF was explained by the magnetoconvection theory. The presence of WMF could accelerate the corrosion rate of Fe3O4 and thus promoted the release of Fe(II), which led to the increased production of •OH and enhanced the degradation of OG. Moreover, it was surprising to observe that the WMF induced improvement in OG degradation by heterogeneous Fenton involving the iron sludge, namely FeOOH and Fe2O3, as catalysts. These results indicated that WMF could be utilized as an efficient and cost-effective strategy to improve the removal of organic pollutants by iron oxide–based Fenton process. [ABSTRACT FROM AUTHOR]

The bacteria were isolated and identified from textile effluent, and their ability to decolorize the hazardous azo dye Orange G was evaluated. After incubating the isolates for 24 hours in mineral salt medium supplemented with 100 ppm Direct Orange G, their decolorizing activity was measured spectrophotometrically. Lysinibacillus sp. AUBTP7 (AK1), Bacillus muralis strain1Y118 (AK2), and Bacillus thuringiensis strain N3 (AK3) were identified as the bacterial strains. Bacillus thuringiensis strain N3 (AK3) was the most efficient bacteria at decolorizing Orange G (100ppm), removing 93% of the color in 24 hours at 36ºC temperature. Study of HPLC chromatogram of Orange G and degradation products suggests the formation of new compounds. As a result of this research, it has been revealed that some bacteria live in textile effluents and use dyes as a source of energy and nourishment, implying their usefulness in the treatment of industrial effluents. [ABSTRACT FROM AUTHOR]

Nanoflowers and nanorods of ZnO were synthesized via hydrothermal route. These morphologies of zinc oxide (ZnO) were then decorated over graphene oxide (GO) to yield hybrid nanocomposites, namely, GO-ZnOnR and GO-ZnOnF. The decoration of ZnO nanorods and nanoflowers on GO layers was confirmed through FESEM images. The synthesized nanocomposites were subjected to degrade the Orange G under identical conditions. The band gap energies determined using diffused reflectance spectra were 2.87, 2.89 eV for GO-ZnOnR, and GO-ZnOnF, whereas, for both ZnOnR and ZnOnF, it was 3.14 eV. For 50 min of UV irradiations (at 6 pH), 100% degradation was achieved corresponding to GO-ZnOnR (44.1 m2 g-1) followed by 90.1%, 70.2%, and 68.3% with GO-ZnOnF (35.9 m2 g-1), ZnOnR (20 m2 g-1), and ZnOnF (15.1 m2 g-1), respectively. Significant boost in the degradation of Orange G, with GO-ZnOnR, was attributed to its reduced band gap, higher surface area, and enhanced charge separation. Kinetic study confirms the pseudo-first-order reaction rate. Mineralization efficiency of 91% in 120 min indicated the efficient reduction of Orange G and its intermediates. Further, reactive species trapping experiments revealed that photo-induced •OH are dominant radicals for the degradation followed by •O2- and h+. Liquid chromatography mass spectra data has been used to predict the plausible reaction pathways. Reusability studies indicated that GO-ZnOnR can be used for four successive degradation cycles, without any significant activity loss. [ABSTRACT FROM AUTHOR]

The presence of harmful substances such as dyes in water systems poses a direct threat to the quality of people's lives and other organisms living in the ecosystem. Orange G (OG) is considered a hazardous dye. The existing paper attempts to evaluate a low-cost adsorbent for the effective removal of OG dye. The developed adsorbent Polyaniline@Hydroxyapatite extracted from Cilus Gilberti fish Scale (PANI@FHAP) was elaborated through the application of the in situ chemical polymerization method to incorporate PANI on the surface of naturally extracted hydroxyapatite FHAP. The good synthesis of PANI@FHAP was evaluated through multiple techniques including X-ray diffraction (XRD), Scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM/EDS), Fourier Transforms Infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) coupled with thermal differential analysis (DTA) analysis. The results reveal a highly ordered disposition of PANI chains on FHAP, resulting in a well-coated FHAP in the PANI matrix. Furthermore, the presence of functional groups on the surface of PANI such as amine (-NH 2) and imine (=NH) groups would facilitate the removal of OG dye from contaminated water. The adsorption of OG onto PANI@FHAP was conducted in batch mode and optimized through response surface methodology coupled with box-Behnken design (RSM/BBD) to investigate the effect of time, adsorbent dose, and initial concentration. The outcomes proved that OG adsorption follows a quadratic model (R2 = 0.989). The kinetic study revealed that the adsorption of OG fits the pseudo-second-order model. On the other hand, the isotherm study declared that the Freundlich model is best suited to the description of OG adsorption. For thermodynamic study, the adsorption of OG is spontaneous in nature and exothermic. Furthermore, the regeneration-reusability study indicates that PANI@FHAP could be regenerated and reused up to five successive cycles. Based on the FTIR spectrum of PANI@FHAP after OG adsorption, the mechanism governing OG adsorption is predominantly driven by π-π interaction, electrostatic interaction, and hydrogen bonding interactions. The obtained results suppose that PANI@FHAP adsorbent can be a competitive material in large-scale applications. [Display omitted] • · Evaluation of a low-cost Polyaniline@Hydroxyapatite adsorbent for efficient removal of OG dye. • · OG adsorption on PANI@FHAP fits PSO kinetics and a Freundlich isotherm. • Thermodynamic study shows the spontaneous and exothermic nature of OG adsorption onto PANI@FHAP. • OG adsorption mechanism is governed by π-π interaction, electrostatic interaction, and hydrogen bonding interactions. • PANI@FHAP demonstrates potential as an environmentally sustainable composite adsorbent. [ABSTRACT FROM AUTHOR]

Digital Light Processing (DLP) enables high precision 3D-printing of photopolymers and holds promising potential for patient-specific implant solutions. On the material side, Poly(ethylene glycol) diacrylate (PEGDA) has emerged as an interesting material for use in biomedical applications. For adequate photopolymerization, a photoinitiator and a light absorber are necessary, using welldefined concentrations. This study shows preliminary results of DLP 3D-printing of different PEGDA hydrogel compositions with varying water content (90; 70; 50; 30; 10; 0 % w/w) as well as varying concentrations of a photoinitiator and a light absorber. Printing performance and accuracy are investigated by printing rectangular test samples as well as an anatomically customised tubular frontal sinus implant prototype. For basic mechanical characterisation, the hardness of the printed hydrogels is investigated using a Shore A durometer. The results show a decrease in printing accuracy and hardness with an increasing water content of the composition. There is a need to use a light absorber to reach high printing accuracy. This leads to a need for increasing photoinitiator concentration and prolonged light exposure to achieve proper printing performance.

This work details the preparation and characterization of a tetracarboxyzinc phthalocyanine (ZnTCPc) immobilized onto silica gel coated with gold nanometal (Au@SiO2) and investigates its photocatalytic activity for the first time. The immobilization of ZnTCPc on the Au@SiO2 surface was performed through pre‐anchorage of cysteine (CSH) via the post‐synthesis method, and then the ZnTCPc was conjugated to the nanometal surface (Au@SiO2) with an amide bond to obtain a heterogeneous photocatalyst (ZnTCPc−Au@SiO2). The prepared photocatalyst (ZnTCPc‐Au@SiO2) were characterized using various spectroscopic techniques such as Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV‐vis) spectrophotometry, and energy dispersive X‐ray (EDX) spectroscopy. Singlet oxygen quantum yields (ΦΔ) for both ZnTCPc and ZnTCPc‐Au@SiO2 were calculated, and the photocatalytic activity of the photocatalyst was tested for photodegradation of organic pollutants, namely Orange G (OG) and Methyl orange (MO), in aqueous solutions. The photodegradation process concluded in under 25 min. with a 20 mg dose of the ZnTCPc‐Au@SiO2 under visible light irradiation for 5 min. intervals in the presence of organic pollutants. The reusability of the photocatalyst was also tested. The results reveal that the photocatalyst (ZnTCPc‐Au@SiO2) has potential for use in the photodegradation of organic pollutants in industrial wastewater. [ABSTRACT FROM AUTHOR]

Attractive environmentally friendly magnetic metal-organic framework (MOF) nanocomposite GO@Fe3O4-COOH@NH2-MIL-101(Fe) was synthesized by a solvothermal method and characterized by X-ray diffraction, Fourier transform infrared, scanning electron microscopy, Brunauer– Emmett–Teller, and vibrating sample magnetometer, and used as an effective adsorbent for the removal of orange G from aqueous solution. The various operating parameters that effect the adsorption process, such as adsorbent dosage (0.01–0.2 g), pH (1.0–10.0), initial concentration (50–400 mg L–1), and temperature (298.15–318.15 K) were studied. The percent removal of orange G increases with the increment of the adsorbent dosage and decrease of the initial concentration, and the optimum pH is 6.0. The Redlich–Peterson model can be favorably applied to describe the adsorption equilibrium data, indicating that the surfaces of GO@Fe3O4-COOH@NH2-MIL-101(Fe) nanocomposite for the orange G adsorption are made up of homogeneous adsorption patches. The adsorption kinetics indicate that the adsorption process of GO@Fe3O4-COOH@NH2-MIL-101(Fe) toward orange G obeys the pseudo-second-order model and the activation energy is 16.5 kJ mol–1. Thermodynamic parameters, ΔH = 39.81 kJ mol–1, ΔS = –46.80 J mol–1 K–1, and ΔG < 0, exhibit that the adsorption is exothermic and spontaneous. The maximum adsorption capacity of orange G onto GO@Fe3O4-COOH@NH2-MIL-101(Fe) nanocomposite is 128.8 mg g–1. Therefore, magnetic GO@Fe3O4-COOH@NH2-MIL-101(Fe) nanocomposite can be employed as an environmentally friendly and efficient adsorbent for the orange G removal from wastewater. [ABSTRACT FROM AUTHOR]

In this study, zinc layered hydroxide salts (Zn-LHS) intercalated with dodecyl sulfate (DDS) anion in nanocone morphology (LHS-NC) and conventional stone-like co-precipitation LHS phases (LHS-CO) were investigated as adsorbent of Orange G (OG) and Sunset Yellow (SY) dye. LHS-NC was prepared by urea hydrolysis method, while LHS-DDS was prepared by coprecipitation method. XRDP, FTIR, and SEM were used to characterize their structure and showed the formation of layered compounds with very well layered stacking with nanocone and conventional layer stone morphology. After OG and SY adsorption, the results (XRDP, FTIR, UV-Vis, Zetametry) showed that the Freundlich adsorption isotherms had been well fitted, and both OG and SY dyes were intercalated in interlayer space of LHS, where LHS-CO and LHS-NC present high uptake capability of SY dye remotion equal a 227.79 and 442.48 (mg g -1 ) while OG adsorption capability were 2.52 and 6.39 (mg g -1 ), respectively. For the kinetics study, the best fit was obtained by the pseudo-second-order model, whereas the results of intraparticle diffusion show a one-step adsorption process. Hence, this study demonstrated Zn-LHS in nanocone morphology, and conventional stone-like co-precipitation phase makes them potentially attractive adsorbents in water purification. [ABSTRACT FROM AUTHOR]

Manganese oxide-loaded sludge-derived biochar (Mn-SDBC) was synthesized and used to activate persulfate (PS) for Orange G (OG) degradation. X-ray fluorescence and Fourier transform infrared spectroscopy analysis indicated that the manganese oxides were successfully loaded on the SDBC. The result of batch experiments suggests that OG can be efficiently degraded by PS activated by Mn-SDBC. Metal loading rate, biochar dosage and PS concentration play a crucial role in experiments, whereas pH has a minor effect on OG removal. The free radical quenching experiment was investigated to determine the predominant radical species, and the activation mechanism was also illustrated. The as-synthesized Mn-SDBC can efficiently activate PS and removal OG under a continuous flow condition in a fixed-bed column. Our study suggests that Mn-SDBC would be a promising catalyst for the remediation of dye-contaminated wastewater.

An extensive screening of saprotrophic Basidiomycetes causing white rot (WR), brown rot (BR), or litter decomposition (LD) for the production of laccase and Mn-peroxidase (MnP) and decolorization of the synthetic dyes Orange G and Remazol Brilliant Blue R (RBBR) was performed. The study considered in total 150 strains belonging to 77 species. The aim of this work was to compare the decolorization and ligninolytic capacity among different ecophysiological and taxonomic groups of Basidiomycetes. WR strains decolorized both dyes most efficiently; high decolorization capacity was also found in some LD fungi. The enzyme production was recorded in all three ecophysiology groups, but to a different extent. All WR and LD fungi produced laccase, and the majority of them also produced MnP. The strains belonging to BR lacked decolorization capabilities. None of them produced MnP and the production of laccase was either very low or absent. The most efficient decolorization of both dyes and the highest laccase production was found among the members of the orders Polyporales and Agaricales. The strains with high MnP activity occurred across almost all fungal orders (Polyporales, Agaricales, Hymenochaetales, and Russulales). Synthetic dye decolorization by fungal strains was clearly related to their production of ligninolytic enzymes and both properties were determined by the interaction of their ecophysiology and taxonomy, with a more relevant role of ecophysiology. Our screening revealed 12 strains with high decolorization capacity (9 WR and 3 LD), which could be promising for further biotechnological utilization. [ABSTRACT FROM AUTHOR]

The TiO2 and Ag/TiO2 solutions were prepared by the sol-gel method. The solutions were coated on the quartz tubes by using the dip-coating method. The produced TiO2 and Ag/TiO2 thin-film photocatalysts were characterized by using scanning electron microscopy-energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and chronoamperometric measurements. The characterization results showed that the photocatalysts were successfully synthesized, and the Ag/TiO2 thin-film photocatalyst had a higher photocurrent intensity than the TiO2 thin-film photocatalyst. To eliminate the lack of literature in the kinetic study, the synthesized photocatalysts were examined on the degradation of the Orange G solution. The effects of initial dye concentration, temperature, and light intensity on the photocatalytic degradation kinetics of Orange G were investigated. The network kinetic model was applied to determine the appropriate kinetic model for the decomposition of Orange G with the produced photocatalysts. The network kinetic model was found to be the appropriate kinetic model for the degradation of Orange G using the TiO2 and Ag/TiO2 thin film photocatalysts. The calculated activation energies of the TiO2 and Ag/TiO2 thin film photocatalysts by using the result of the experiments are 20.02 and 16.16 kJ/mol, respectively. Besides, the general rate equations for each photocatalyst were specified. [ABSTRACT FROM AUTHOR]

Core-shell nanomaterials have emerged as a frontier area of focus in materials chemistry and catalysis. Here, we have explored the photocatalyst potential of a double layered core-shell material comprising a rare earth material as core and silica, zinc oxide as the subsequent shell materials. The prepared core-shell has average particle size of 40-60 nm, and the material has been characterized by FTIR, XRD, UV-DRS and FESEM techniques. The band gap energy of prepared material is 2.82 eV. The photocatalytic activity has been tested against Orange-G and Malachite green dye under visible light irradiation. A comparison for degradation of azo and non-azo dye has been elucidated. Preliminary studies with varying pH, catalyst dosage and initial dye concentration have been done to determine the optimum parameters for photocatalytic activity. The kinetic studies follow pseudo-first-order pathway. The prepared core-shell nanomaterial is found efficient for degradation of non-azo dye compared to azo dye. Both the materials show better activity than pristine ZnO. The photocatalyst is found to be environmentally benign with reusability even up to the third cycle of reuse. [ABSTRACT FROM AUTHOR]