Degradation Of Dye Wastewater Research Articles

Photothermal degradation of triphenylmethane dye wastewater by Fe3O4@C-laccase

The degradation of synthetic dye wastewater is important for green chemistry and cost-effectiveness. In this study, we developed Fe3O4@C-laccase (laccase immobilized on Fe3O4@C nanoparticles) for photothermal degradation of high concentration of triphenylmethane dye wastewater. The Fe3O4@C-laccase possessed superior pH and thermal stabilities, as well as excellent tolerance to organic solvents, inhibitors, and metal ions. Laccase activity assays revealed that the activity recovery was approximately 118.2 %. Furthermore, the Fe3O4@C-laccase presented rapid and sustainable photothermal degradation capabilities to triphenylmethane dye wastewater. The initial removal efficiencies of 400 mg/L malachite green (MG), 400 mg/L brilliant green (BG), 100 mg/L crystal violet (CV), and 600 mg/L mixed dye (MG:BG:CV = 1:1:1) wastewater were approximately 99.8 %, 99.9 %, 96.4 % and 99.2 % by 60 min treatment, respectively. After undergoing 10 batches of reuse, the photothermal degradation efficiencies of the triphenylmethane dye wastewater remained consistently high, at about 99.3 %, 97.4 %, 94.0 %, and 95.1 %, respectively. The excellent photothermal degradation properties indicate that the Fe3O4@C-laccase holds promise for addressing high concentration of textile wastewater in various applications.

Preparation of Mn-Ce oxide-loaded Al2O3 by citric acid-assisted impregnation for enhanced catalytic ozonation degradation of dye wastewater

The performance of supported catalysts is significantly affected by the dispersion degree of the active components on the support. In this study, citric acid (CA) was used as a modifier to prepare Al2O3 supported Mn-Ce oxides (Mn-Ce/CA-Al2O3) by the impregnation-calcination method. The characterization results showed that adding citric acid enhanced the dispersion of Mn-Ce oxides on the support, rendering Mn-Ce/CA-Al2O3 with a larger specific surface area and abundant surface hydroxyl groups, thereby providing more reaction sites for catalytic ozonation. The Mn-Ce/CA-Al2O3 exhibited excellent catalytic ozonation performance in degrading Reactive Black 5 (RB5) dye. It achieved nearly complete decolorization of RB5 within 60 min, with a COD removal efficiency of 60%, which was superior to the sole ozonation (30%). Furthermore, the Mn-Ce/CA-Al2O3 system demonstrated significant degradation of RB5 over a wide pH range of 3 to 11. Based on the XPS and EPR analysis results, a preliminary mechanism of catalytic ozonation over the Mn-Ce/CA-Al2O3 was proposed. The redox cycle of Mn3+/Mn4+ and Ce3+/Ce4+ effectively accelerated the electron transfer process, thus promoting the generation of reactive oxygen species (ROS) and improving the degradation of RB5. Meanwhile, the Mn-Ce/CA-Al2O3 exhibited superior catalytic stability and effective treatment capabilities for real dye wastewater.

Highly energy-efficient degradation of simulated dye wastewater by array type underwater bubble discharge plasma: Key factors identification and degradation pathways

The extensive use of dyes presents a significant safety concern for the reuse of water resources, highlighting the critical need for a rapid and efficient degradation method for dye mixtures in wastewater. This study introduces a degradation system based on an array type underwater bubble discharge plasma specifically designed to treat a dye mixture wastewater containing methylene blue (MB) and methyl violet 2B (MV2B). Analysis of the optical and electrical characteristics reveals that the device experiences minimal temperature increase, with the highest intensity of the band associated with N2 in the emission spectra, and discharges occurring predominantly during the rising and falling edges of a pulse cycle. Experimental results demonstrate that the most effective degradation efficiencies (MB = 94.83%, MV2B = 93.48%) are achieved at an initial dye concentration of 50 mg/L, a power supply frequency of 6 kHz, an air flow rate of 2.5 SLM and an initial electrical conductivity of 50 μS/cm. The degradation of dyes is primarily attributed to the demethylation process of O3(aq) and other species. Toxicity analysis indicates that the plasma degradation process significantly reduces the toxicity of the intermediate products of dyes. This study not only presents a novel approach for treating high concentration mixed dye wastewater, but also provides valuable insights for future research in this area.

ZrO2 nanoparticles for effective dye degradation in wastewater: Synthesis, characterization, and photocatalytic performance under sunlight

The study addresses the critical issue of water contamination, focusing on the photodegradation of methylene blue (MB) dye as industrial waste. A novel method is presented to synthesize zirconium dioxide (ZrO2) nanoparticles (NPs) using zirconium hydrogen phosphate as a precursor. The results proved the formation of spherical nanoparticles with an average particle size of about 23.24 nm, confirmed by scanning electron microscopy (SEM). The structural analysis demonstrated the existence of both tetragonal and monoclinic phases, with the dominance of the tetragonal phase. The photocatalytic evaluation under sunlight irradiation showed an impressive MB degradation efficiency of about 80 % in a relatively short time of 80 min. Thus, the study highlights the potential of ZrO2 NPs sensitized by a novel approach as highly efficient photocatalysis for water treatment.

Biogenic Syntheses of AgNPs With Leaf Extract Abution indicum and Its Application for Antimicrobial and Photocatalytic Activity

ABSTRACTThe biogenic synthesis of silver nanoparticles (AgNPs) with leaf extract Abution indicum was done, and those were characterized by ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), powder X‐ray diffraction (PXRD), field emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM) with energy‐dispersive X‐ray (EDX) spectroscopy. The analysis by UV–vis spectroscopy showed a peak of 450 nm, and DLS and zeta potential were utilized to determine the size distribution of the biosynthesized Abution indicum–AgNPs (AI‐AgNPs) with a size range of 24–37 nm, and the X‐ray diffraction peak 38.096o was used to confirm that the crystalline structure of AI‐AgNPs. Furthermore, the antipathogenic effect of synthesized AgNPs and standard antibiotic (Ciprofloxacin) as studied the positive control in different types of bacterial pathogens likes Staphylococcus aureus and Escherichia Coli, with the zone of inhibition values of 9 mm. The synthesized AgNPs displayed excellent photocatalytic activity against reactive blue under sunlight than a UV light irradiation, and maximum degradation of 43% was achieved with 66 min of reaction time. In view of promising activity, the AgNPs could be used photocatalyst for the degradation of dyes in wastewater, and pomegranate leaf extract can be applied as eco‐benign and cost‐effective approach for AgNPs synthesis. Hence, the current findings suggest that Abutilon indicum is a valuable source for tailoring the potential of AgNPs toward various enhanced biological, photocatalytic, and adsorption activities. Consequently, the plant biological molecule‐mediated synthesized AI‐AgNPs could be excellent contenders for future therapeutic applications.

Enhanced piezo-photocatalytic performance of ZnO/BNBT-6 heterojunction via piezoelectric effect for degradation of dye wastewater

The combination of mechanical energy and solar energy is considered as an effective strategy to solve energy and environmental problems. Here, we prepare ZnO/(Na0.5Bi0.5)0.94Ba0.06TiO3(ZnO/BNBT-6) heterostructure, which significantly enhances the piezo-photocatalytic degradation performance by the piezoelectric effect induced under the built-in electric field. The catalytic oxidation capacity of the ZnO/BNBT-6 heterostructure was significantly improved, and the reaction rate constant can be up to 0.07335 min-1 under ultrasonic vibration and ultraviolet visible light irradiation, which is much higher than that of photocatalysis and piezocatalysis. This excellent performance occurs because a built-in polarization field is generated inside the BNBT-6 nanorod by ultrasound, which can accelerate effective separation of photogenerated e−-h+ pairs in BNBT-6 and ZnO, therefore, enhancing the activity of the heterojunction. Finally, a possible piezo-photocatalytic degradation mechanism was proposed based on the free radical trapping experiment and experimental results. This study provides a valuable reference for the design of high efficient piezo-photocatalysts.

Copper supported Dowex50WX8 resin utilized for the elimination of ammonia and its sustainable application for the degradation of dyes in wastewater

To obtain high efficient elimination of ammonia (NH4+) from wastewater, Cu(II), Ni(II), and Co(II)) were loaded on Dowex-50WX8 resin (D-H) and studied their removal efficiency towards NH4+ from aqueous solutions. The adsorption capacity of Cu(II)-loaded on D-H (D-Cu2+) towards NH4+ (qe = 95.58 mg/g) was the highest one compared with that of D-Ni2+ (qe = 57.29 mg/g) and D-Co2+ (qe = 43.43 mg/g). Detailed studies focused on the removal of NH4+ utilizing D-Cu2+ were accomplished under various experimental conditions. The pseudo-second-order kinetic model fitted well the adsorption data of NH4+ on D-Cu2+. The non-linear Langmuir model was the best model for the adsorption process, producing a maximum equilibrium adsorption capacity (qmax = 280.9 mg/g) at pH = 8.4, and 303 K in less than 20 min. The adsorption of NH4+ onto D-Cu2+ was an exothermic and spontaneous process. In a sustainable step, the resulting D-Cu(II)-ammine composite from the NH4+ adsorption process displayed excellent catalytic activity for the degradation of aniline blue (AB) and methyl violet 2B (MV 2B) dyes utilizing H2O2 as an eco-friendly oxidant.

Dual-Function Photocatalysis in the Visible Spectrum: Ag-G-TiO2 for Simultaneous Dye Wastewater Degradation and Hydrogen Production

Dual-Function Photocatalysis in the Visible Spectrum: Ag-G-TiO2 for Simultaneous Dye Wastewater Degradation and Hydrogen Production

A novel graphene-N/TiO2-nickel foam: Preparation and application in photoelectric synergistic degradation of methyl orange

Photoelectric synergistic degradation of dye wastewater has been developed. In this experiment, we prepared Nitrogen-doped titanium dioxide-graphene/nickel foam (N/TiO2-Gr/F–Ni) by electrophoresis and impregnation methods, to degrade methyl orange (MO) aqueous solution. Firstly, nitrogen-doped titanium dioxide particle (N/TiO2) was prepared by the sol-gel method, which showed a photocatalytic degradation catalytic kinetic constant of 1.8 × 10−2 min−1 under simulated sunlight. Meanwhile, graphene (Gr) was loaded on nickel foam (F–Ni) to prepare Gr/F–Ni electrode by electrophoresis method, which obtained a catalytic kinetic constant of 1.15 × 10−2 min−1 at 10 V. Finally, N/TiO2 was loaded on Gr/F–Ni to prepare N/TiO2-Gr/F–Ni photoelectrode by electrophoresis and impregnation methods, which had a catalytic kinetic constant of 3.96 × 10−2 min−1 at 10 V and under 1 sun. The results show that there is a synergistic effect between light degradation and electro-Fenton oxidation because the bonding electrons in N/TiO2 are activated to produce photogenerated electron-hole pairs. On the other hand, the separation efficiency of the photogenerated electron is enhanced by the Gr.

Wood-supported nitrogen-doped carbon quantum dot @Cu2O composites for efficient photocatalytic degradation of dye wastewater

Wood-supported nitrogen-doped carbon quantum dot @Cu2O composites for efficient photocatalytic degradation of dye wastewater

Efficient solar utilization: Multifunctional solar absorber devices realize self-driven hydrogen production

Considered as one of the effective approaches to address the energy crisis and develop green and sustainable energy, the application of solar energy in multiple stages was investigated in this study. By designing a WS2/ZnIn2S4 heterojunction, a multifunctional coupling system based on interfacial water evaporation technology was constructed. In this system, the water evaporation rate was 1.67 kgꞏm−2ꞏh−1, and the photocatalytic degradation efficiency of rhodamine B reached 96.5 %. Moreover, the electric energy output from thermoelectric conversion was innovatively in situ applied for photocatalytic hydrogen production, which increased the photocatalytic hydrogen production efficiency by five times, with a hydrogen production rate of 40.3 μmolꞏcm−2ꞏh−1. This study successfully integrated thermoelectric power generation, photocatalytic hydrogen production, and photocatalytic degradation of dye wastewater into an advanced solar-driven interface evaporation system, enabling the simultaneous conversion of solar energy into multiple forms of energy, improving solar energy utilization efficiency, which was of great significance for promoting the practical application of solar energy.

Fe-S Co-doped Porous Carbon Catalyzed Oxidation and Degradation of Dye Wastewater

Fe-S Co-doped Porous Carbon Catalyzed Oxidation and Degradation of Dye Wastewater

Stability and photocatalytic performance enhancement of sodium-doped CsPbBr3/Cs4PbBr6 nanocomposites for dye wastewater degradation

The extremely poor stability of lead halide perovskites has always been a challenge. In this paper, CsPbBr3 nanocrystals, CsPbBr3/Cs4PbBr6 nanocomposites and Na-CsPbBr3/Cs4PbBr6 nanocomposites were prepared by thermal injection and ligand-assisted reprecipitation method. The photocatalytic effect and stability of CsPbBr3 in aqueous systems were significantly improved by sodium ions doping and complexation with Cs4PbBr6. The results showed that the photocatalytic degradation rate of 5% Na-CsPbBr3 for Sudan red (III) was 57.8% within 180 min, while that of pure CsPbBr3 was only 14.47%. In the CsPbBr3/Cs4PbBr6 nanocomposites, Na-CsPbBr3/Cs4PbBr6 nanocomposites photocatalyzed nearly 94% of Sudan red (III) in 120 min, while CsPbBr3/Cs4PbBr6 photocatalyzed only 56% of organic dyes in the same time. Cs4PbBr6 can passivate CsPbBr3 in situ to enhance the stability of the perovskite material. In the four cyclic degradation experimental tests in aqueous systems, the nanocomposites maintained good stability performance. This study provides a new way to improve the catalytic performance and stability of perovskite materials.

Innovative TiO2-doped polyvinyl alcohol sponge for efficient oil–water separation and dye degradation in wastewater treatment

Regular problems faced due to oil spills and soluble contaminants have increasingly caused serious water pollution. Therefore, there is an urgent need to develop efficient strategies to purify wastewater. This study aims to formulate a synergistic treatment technology of sorption and ultraviolet light catalysis for oil–water separation and degradation of dyes in wastewater. In this study, TiO2 doped PVF sponge (DTMS-TiO2@PVF) was prepared with a water contact angle of 151.5° and a removal rate of 98.86 % of MB in 120 min. Meanwhile, DTMS-TiO2@PVF sponge could easily realize the selective separation of oil–water mixtures. Its saturated sorption capacity for oil and organic solvent was 4.13–10.05 g/g. In addition, DTMS-TiO2@PVF sponge had better environmental stability, which could withstand chemical corrosion (acid, alkaline, and salt solutions). Therefore, DTMS-TiO2@PVF sponge showed great potential for application as an efficient oil–water separation and photocatalytic material, especially in the field of treating oil wastewater and water purification.

Construction of the VOBiOBr/VSZnIn2S4 heterojunction for photocatalytic hydrogen production and dye removal under simulated sunlight

Semiconductor photocatalysis is a promising method for utilizing solar energy to decompose water and degrade pollutants. However, the limited visible light absorption capacity and high carrier complexation rate hinder the utilization of sunlight for photocatalysts. The study prepared VOBiOBr/VSZnIn2S4 S-scheme heterojunction photocatalysts with sulfur and oxygen vacancies using a two-step solvothermal method. The photocatalyst was then used to simulate sunlight decomposition of water for hydrogen production and degradation of dye wastewater. Characterisation tests revealed that the incorporation of sulfur and oxygen vacancies effectively enhanced the visible light absorption of BiOBr and ZnIn2S4. The construction of S-scheme heterojunction resulted in an improvement in visible light absorption capacity, as well as the promotion of separation and migration of photogenerated carriers. The study demonstrates that VOBiOBr/VSZnIn2S4 exhibits superior hydrogen precipitation and degradation properties compared to BiOBr/ZnIn2S4 without S and O vacancies and VSZnIn2S4 without a heterojunction when subjected to simulated sunlight irradiation. The results of the tests and mechanistic analyses suggest that the synergistic effect of S and O vacancies and heterojunction enhances the photocatalytic performance. This study offers novel perspectives on the production of multifunctional photocatalysts that effectively utilize sunlight.

Degradation of Anthraquinone dye wastewater by sodium percarbonate with CoO heterogeneous activation

AbstractBACKGROUNDAnthraquinone dyes have an anthraquinone structure as their nucleus, with one or more substituents forming different organic dyes. Anthraquinone dyes have a complex structure that allows them to exist stably in water environment, but also makes them more toxic than azo dyes. This results in varying degrees of harm to both humans and the environment as a result of residual dyes in the water or on the material’ surface. Sodium percarbonate (SPC) is a highly promising oxidant due to its green end product. Therefore, in this study, the catalytic performance and kinetic study of cobalt oxide (CoO) on SPC under different conditions were systematically investigated using RB19 as the target pollutant. The Box–Behnken Design (BBD) model was used to model the degradation of RB19 by CoO/SPC system, which gives the basis for practical application. The types of reactive oxygen species that effectively degrade RB19 and the potential degradation mechanism of the CoO/SPC system were revealed. At the same time, the CoO/SPC system was evaluated in terms of its practicality.RESULTSIn this work, the activation of SPC using CoO towards reactive blue 19 (RB19) degradation was explored. Experimental results showed that nearly 93.8% of RB19 could be removed within 30 min using 1 mmol L−1 SPC and 30 mg L−1 CoO. The three‐factor interaction effects of SPC concentration, CoO dosage and initial pH were investigated. The BBD model was set up to obtain the optimum working conditions of 1.039 mmol L−1 SPC, 33.35 mg L−1 CoO and the initial pH of 7.82, which gave a degradation rate of 95.372%. Additionally, it was confirmed that the solubility of Co2+ is consistently <150 μg L−1, meeting the emission standard (1 ppm). The presence of Cl−, NO3–, and HA had a similar profile, with a slight promoting effect in small amounts and an inhibitory effect when introduced in excess. The introduction of SO42– had a negligible effect on RB19 degradation, whereas the presence of HCO3− produced a slight inhibitory effect. Furthermore, the presence of PO43– showed a strong inhibitory effect. The CoO/SPC system is suitable for other organic dyes (32.7%–100%) and antibiotics (97.1–100%). Electron paramagnetic resonance (EPR) analysis and quenching experiments confirmed the presence and relative contribution of free radicals in the CoO/SPC system as CO3•‐ (88.12%) >O2•‐ (51.11%) >1O2 (37.21%) >•OH (5.27%) > SPC (3.33%) >CoO (0.09%). It has been confirmed that CoO activates SPC through electron transfer.CONCLUSIONThe present study describes a less time‐consuming, and more efficient method of treating anthraquinone dye wastewater that requires less oxidizer and catalyst, making it more economical. This proposes a straightforward, cost‐effective and efficient technique using SPC triggered by transition metal oxides. © 2024 Society of Chemical Industry (SCI).

Facile fabrication of Zn-doped CuAl2O4 nanofiber membranes for photocatalytic degradation of dye wastewater

Facile fabrication of Zn-doped CuAl2O4 nanofiber membranes for photocatalytic degradation of dye wastewater

Degradation of reactive red (B-3BF) dye wastewater using UV irradiation (254/185 nm) with sodium persulfate in a pilot UV device

Two low-pressure ultraviolet (UV) lamps at 185/254 nm with sodium persulfate in a pilot UV device were utilized for the degradation of reactive red (B-3BF) dye wastewater compared with two UV lamps at 185/185 nm and two UV lamps at 254/254 nm. The degradation performances of UV irradiation (254/185 nm) with sodium persulfate under different degradation times, flow rates, initial pH, initial Na2S2O8 concentrations and initial dye concentrations were investigated. The experimental results illustrated that the degradation percentage of B-3BF dye could reduce to 90.42% with the energy consumption of 85.1 kWh/kg and the residual dye concentration of 1.92 mg/L by UV irradiation (254/185 nm) with initial Na2S2O8 concentration of 1.5 mmol/L and initial dye concentration of 20 mg/L. In addition, degradation performance of B-3BF dye wastewater by UV irradiation (254/185 nm) with sodium persulfate was more effective than those of UV irradiation (254/254 nm) and UV irradiation (185/185 nm). Therefore UV irradiation (254/185 nm) with sodium persulfate was promising for the degradation of B-3BF dye wastewater.

Preparation and Characterization of C@Fe3O4 Supported Pd Magnetic Nanoparticles for Degradation of Dye Wastewater

The core-shell structure Fe3O4@C magnetic nanoparticles were synthesized with superparamagnetic Fe3O4 nanosphere as a magnetic core, and soluble starch resin as a carbon source via a solvothermal method. Silica-iron oxide and Fe3O4@C carriers with a core-shell structure were prepared by carbonization of organic material on the surface of Fe3O4 nanoparticles, Fe3O4@C supported Pd were processed into magnetic nano-catalysts with core-shell structure, and their catalytic properties were investigated. The resulting environmentally friendly magnetic material can be used to degrade dye wastewater. The structure of magnetic nanoparticles was characterized using TEM, XRD and VSM. The effects of preparation conditions in the structure of the Fe3O4@C magnetic nanoparticles were taken out. The results indicate that from XRD, the magnetic nano particles Fe3O4@C synthesized of carbon sources have amorphous carbon diffraction peak except for all the characteristic peaks of Fe3O4. The saturation magnetization Fe3O4, Fe3O4@SiO2 and Fe3O4@C – 59.14 emu/g, 49.12 emu/g and 27.95 emu/g, respectively.

Functionalized nitrogen-enrich graphene as a highly efficient photocatalyst for oxidative cyclization of thioamide and degradation of Dye

Functionalized photocatalysts have shown to be an effective method for oxidative cyclization processes and the degradation of organic poisons like chemicals and dyes. In this study, we report the facile, environmentally friendly, room-temperature (RT) synthesis and development of a graphene-based visible light active photocatalyst (NenG-RhB) which is thermodynamically converted to nitrogen-enriched graphene (NenG) covalently bonded to a light-harvesting RhB molecule [9-(2-Carboxyphenyl)-6-(diethylamino)-N, N‑diethyl-3H-xanthen-3-iminium chloride)]. The NenG-RhB photocatalyst is extremely effective, resulting in good oxidative cyclization of aromatic thioamide (92.5 %) and degradation efficiency of industrial orange G (97.29 %) under solar light. The current research focuses on the invention and implementation of a nitrogen-enrich graphene-based photocatalyst for direct solar medicinal chemical synthesis and industrial dye degradation in wastewater using solar light.