Textile Dye Research Articles

Bio-inspired synthesis of Cm-Ag/NiO nanocomposites: Enhanced photocatalytic degradation of textile dyes

This study successfully syntheses Cm-Ag/NiO nanocomposites (NCs) using an eco-friendly approach with Cucumis maderaspatanus L. leaf extract, highlighting a promising avenue for sustainable nanomaterial development. The nanocomposites were calcined at temperatures ranging from 300 to 700 °C to optimize their bandgap, achieving a value of 2.94 eV as determined by UV-Tauc plots. Characterization techniques revealed a face-centered cubic structure via X-ray diffraction, while transmission electron microscopy (TEM) showed uniformly spherical NCs with an average particle size of 7.1 nm. X-ray photoelectron spectroscopy (XPS) confirmed the elemental composition and oxidation states, while thermogravimetric analysis (TGA) and zeta potential measurements indicated robust thermal and colloidal stability. Photocatalytic experiments demonstrated degradation efficiencies of 83.16 % for the textile dye BB41 and 90.19 % for ROM2R under optimized conditions, with degradation kinetics following a first-order reaction model. Additionally, degradation products were identified via LC-MS, and toxicity was evaluated using ECOSAR software, shedding light on the environmental implications of our photocatalytic process. These findings establish Cm-Ag/NiO NCs as highly effective photocatalysts and sustainable solutions for addressing dye pollution in wastewater treatment, paving the way for innovative applications in environmental remediation.

Enhancing Environmental Remediation: Advancements in Chemically Crosslinked Cyclodextrin‐Based Materials for Organic and Inorganic Pollutant Removal

AbstractConcern over the harmful impacts of pollutants on human health and the environment has increased in recent decades due to their widespread presence in water resources. These pollutants include pesticides, poisonous textile dyes, and micropollutants. It is essential to remove these pollutants from wastewater to enhance the quality of water for industrial usage. Because of externally hydrophilic and internally hydrophobic qualities, cyclodextrin and its derivatives have shown great promise as adsorbents for the treatment of wastewater. While cyclodextrins cannot be used as adsorbents on their own due to their water solubility, they can be efficiently polymerized with different types of cross‐linkers to increase their stability and effectiveness. This review article examines chemically crosslinked materials based on cyclodextrin and its derivatives, utilizing various cross‐linkers such as epichlorohydrin, glutaraldehyde, citric acid, N,N′‐methylene bisacrylamide and maleic anhydride. These materials are evaluated for their effectiveness in adsorbing textile dyes, micropollutants, pharmaceuticals, and pesticides from wastewater. Additionally, this article provides a detailed explanation of adsorption kinetics, thermodynamics, and kinetic isotherms for the removal of contaminants. It also discusses the mechanism of contaminant adsorption, and reusability of adsorbents. Finally, this study delves into the challenges and exciting future prospects of CD‐based adsorbents, highlighting their potential to revolutionize wastewater treatment.

Efficient removal of congo red and cytotoxicity evaluation of biosorbents prepared from chitosan-added watermelon pulp

The development of environmentally friendly adsorbents has become increasingly important for treating waste generated by the growing global industry. In this study, new biosorbents were synthesized from an all-natural chitosan and watermelon pulp for the treatment of congo red textile dye from water. Biosorbents were prepared by lyophilizing chitosan-added watermelon pulp (AC-WPC). The prepared biosorbents were characterized by BET, SEM, Zeta Potential and FT-IR analysews. Accordingly, the BET surface area of AC-WPC was 120.92 m2/g. SEM analysis showed that the structures were porous and the results were consistent with the BET analysis. FT-IR analysis confirmed the chemical structures. The isoelectric points of the biosorbents were determined by zeta potential analysis. The AC-WPC biosorbent demonstrated 86% cell viability with cytotoxicity testing. For this reason, it was determined that the AC-WPC biosorbents produced does not cause any serious damage to the cell. Following this, adsorption study of congo red textile dye in water was carried out with these biosorbents. Langmuir and Freundlich isotherms were studied in adsorption experiments, and it was found that the Freundlich isotherms were compatible. Pseudo first and second kinetic models were also studied and found to be compatible with Pseudo Second Kinetic Model. The highest adsorption capacity was observed at 100 mg/l congo red concentration with 98.02% removal and 490.1 mg/g adsorption capacity using AC-WPC. It is thought that these results will potentially contribute to the literature on the removal of textile dyes or other pollutants using chitosan-added watermelon pulp.

Limonene biosolvent-based non-aqueous dyeing medium for salt-free and alkali-free rhamnolipid (RL) biosurfactant reverse micellar dyeing of cotton fabric with reactive dyes

The feasibility of using different forms of limonene biosolvents as dyeing medium in rhamnolipid (RL) biosurfactant-based reverse micellar dyeing system for cotton fabrics is investigated, with different dyeing profiles. Experimental results reveal that limonene-dyed fabrics can achieve generally higher colour yield than water-dyed fabrics while samples dyed by one-step dyeing method could obtain higher colour yield, but poorer relative unlevelness index (RUI) values when compared with samples dyed by two-step method. The CIE L*a*b* value and reflectance of water-dyed and limonene-dyed samples were examined. The pH value of aqueous and non-aqueous dye liquor was measured. SEM images of limonene-dyed cotton fabrics and TEM images of reverse micelle morphology were evaluated. Washing and crocking fastness of the dyed samples were also assessed. The resulting evidence validate that limonene is feasible for reverse micellar reactive dyeing of cotton fabric with the use of RL biosurfactant and it can be one of the alternative solvents, making the dyeing process more natural, more biodegradable and environmentally more sustainable.

Eco-friendly and low-cost phytodyeing for wool, cotton and polyester textile materials using Parthenocissus Quinquefolia L. Fruit Extracts

This study investigates the extraction of natural colorant from fresh fruits of Parthenocissus quinquefolia L. and the application of the extracted dye to wool yarn, cotton, and polyester fabrics in the presence and absence of various mordants. The effect of mordant type on the dyeing quality with different mordanting methods was examined. Iron sulfate, tin chloride, alum, copper sulfate, and potassium dichromate were used as mordant. The effects of these mordants on the color of the dyed samples were investigated in terms of CIELab (L*, a*, b*) and K/S values. The light, washing and rubbing fastness of the dyed samples were evaluated according to ISO standards. While dyeing wool yarn without mordant produces reddish brown, and dyeing with mordant produces a wide range of colors from green to purple, blue and lilac tones are obtained in cotton fabric dyeing, and green, purple and brown tones are obtained in polyester fabric dyeing. While polyester fabrics are dyed with synthetic dyes at 130 oC, in this study they were dyed with natural dyes at 90 oC. As a result of dyeing, colors with high fastness are generally obtained.

Microwave-Assisted Hydrothermal Synthesis of Photocatalytic Truncated-Bipyramidal TiO2/Ti3CN Heterostructures Derived from Ti3CN MXene.

TiO2/MXene heterostructure has garnered significant interest as a photocatalyst due to its large surface area and efficient charge carrier separation at the interface. However, current synthesis methods produce TiO2 without clear crystal faceting and often require complicated postprocessing step, limiting its practical applications. We demonstrate a facile and controlled microwave-assisted hydrothermal synthesis for transforming multilayered Ti3CN MXene to a truncated-bipyramidal TiO2/Ti3CN heterostructure. The resulting TiO2 nanocrystals at the Ti3CN surface exhibited crystalline anatase truncated bipyramids, exposing {001} and {101} facets. We further tailored an indirect optical band gap of the TiO2/Ti3CN heterostructure in the range of 3.17-3.23 eV by varying the hydrothermal synthesis time from 15 min to 5 h at a fixed temperature of 160 °C. Efficient charge separation allowed us to decompose 97% of methylene blue (MB) within 30 min of ultraviolet (UV) light irradiation, ∼3.9-fold faster than the benchmark P25, higher than any other TiO2/MXene heterostructures. With simulated white light, we achieved over 60% efficiency of the dye decomposition within 2 h of irradiation, which resulted in 1.5-fold faster kinetics than P25. We also observed a similar excellent performance of Ti3CN-derived TiO2 in decomposing various persistent synthetic dyes, including commercial textile dye, methyl orange, and rhodamine B. In conclusion, our study provides a strategy for utilizing MXene chemical reactivity to produce highly crystalline optically active TiO2/Ti3CN heterostructure. The developed heterostructure can serve as an efficient photocatalyst for the degradation of organic pollutants.

Extraction of Dye from Waste Blue Gel Pen Ink Using the Voltine Method and Its Application in Fabric Dyeing: An Eco-friendly Approach

Extraction of Dye from Waste Blue Gel Pen Ink Using the Voltine Method and Its Application in Fabric Dyeing: An Eco-friendly Approach

One-bath dyeing and antibacterial finishing of cotton fabric using reactive dye and silver chloride: a sustainable approach

One-bath dyeing and antibacterial finishing of cotton fabric using reactive dye as colorant and silver chloride (AgCl) as an antibacterial agent was conducted to streamline the process and enhance its economic efficiency. The effectiveness of the antibacterial agent in reactive dyeing of cotton fabric, was evaluated through exhaust method with 0.5% AgCl and continuous (pad dry cure) method with 5 g/l of AgCl, utilizing various dye concentrations (1%, 3%, 5% for exhaust; 1g/l, 3g/l, 5g/l for pad dry cure) according to a standard reactive dye recipe. Characterization of the one-bath dyed, and antibacterial finished cotton fabric was performed using K/S values to determine the optimal dye shade concentration and antibacterial activity was evaluated using agar diffusion method. It was observed that the exhaust method revealed an optimum dye concentration at (AgCl 0.5% and dye 5%), while pad dry cure method showedoptimal dye concentration at (AgCl 5g/l and dye 5g/l). Antibacterial tests were conducted on the optimal specimens from both methods (AgCl 0.5%, 0.2%, dye 0.5% for exhaust; dye 5g/l, AgCl 5g/l, 2g/l for pad dry cure), showcasing resistance against bacterial growth. While inhibition zones were observed on treated specimens of the exhaust method, whereas the treated specimens of the pad dry cure method exhibited complete resistance to bacterial growth around the specimen.

Synergistic photocatalytic activity of Bi2O3/g-C3N4/ZnO ternary heterojunction with dual Z-scheme charge transfer towards textile dye degradation

It is clear that a wide range of organic substances, including synthetic textile dyes, have the potential to negatively impact the environment. It is crucial to rationally develop highly effective photocatalysts for the degradation of such type of pollutants. In this regard, a heterostructured photocatalyst comes with enhanced charge separation and extended light absorption ability that improves photocatalytic performance. Therefore, In this study, a Bi2O3/g-C3N4/ZnO (BCNZ) ternary heterojunction photocatalyst was synthesized for the degradation of methylene blue (MB) textile dye.. Thermal polycondensation method was opted to synthesize g-C3N4, while ZnO and Bi2O3 photocatalysts were fabricated using co-precipitation method. Similarly, ternary heterojunction of BCNZ was constructed through co-precipitation method. The ternary heterojunction photocatalyst demonstrated better photodegradation ability due to dual Z-scheme charge transfer route. The dual Z-scheme heterojunction enabled the ternary heterojunction to exhibit enhanced light absorption capabilities with reduced recombination rates as well as enhanced charge separation and migration efficiency (confirmed via transient photocurrent response) that resulted in improved photocatalytic performance. The BCNZ dual Z-scheme photocatalyst displayed 92 % of degradation efficiency which was much higher than that of other (binary and pristine) photocatalysts. Scavenging tests and electron spin resonance spectroscopy revealed the significant role of the •O2−, and •OH radicals in the photodegradation of MB. Furthermore, the reusability test presented good stability and recyclability of the ternary photocatalyst with 80 % degradation efficiency after five catalytic cycles.

Dual-functional MnS nanomaterials: Efficient adsorbent for phosphate removal and sonocatalyst for textile dye degradation

Naturally abundant, environmentally friendly alternatives for replacing the expensive lanthanum-based phosphate removal technique are sought after. Solocatalysis is an emerging area for water remediation. This study introduces a dual-functional MnS nanomaterial for removing phosphate ions and Congo Red textile dye. MnS nanomaterials were synthesized via a hydrothermal route. Batch adsorption experiments revealed a phosphate adsorption capacity of 160.73 mg P/g, commendable for adsorbent in its bare form. Thermodynamic parameters of the process indicated a spontaneous, exothermic process, confirming favourable adsorption. FTIR analysis confirmed the adsorption mechanism, which includes electrostatic attraction, surface complexation, and ion exchange. MnS maintained its adsorption capacity despite competing ions, demonstrating a selective affinity for phosphate ions. MnS showed high sonocatalytic efficiency, degrading Congo Red dye within 10 min of ultrasonic irradiation. The degradation mechanism of Congo Red dye in the sonocatalytic process is proposed. This novel metal chalcogenide material exhibits exceptional affinity for phosphate ions and Congo Red dye molecules, surpassing La-based adsorbents in efficacy. The results suggest that MnS nanomaterials are promising for practical applications in phosphate removal and textile dye degradation from wastewater.

LITERATUR STUDI MENGENAI ADSORBEN LIMBAH CANGKANG HEWAN LAUT DALAM BERBAGAI KEILMUAN

The utilization of marine animal waste as a base material for adsorbents has become an increasingly popular research topic across various scientific fields, including chemistry, environmental science, and materials science. Waste from marine animals, such as crab shells, oyster shell, seashell, and shrimp shell, possesses high potential to be processed into adsorbents due to their abundant calcium carbonate, chitosan, and protein content. The use of this waste as adsorbents not only provides a solution to environmental issues related to the accumulation of organic waste but also offers cheaper and eco-friendly alternative for water treatment, air purification, and contaminated soil remediation. Research has shown that marine animal waste-based adsorbents are effective in removing various pollutants, including heavy metals, textile dyes, and hazardous organic compounds. With specific modification techniques, the performance of these adsorbents can be enhanced, making them competitive with commercial adsorbents. Overall, the use of marine animal waste as adsorbents represents an innovative approach that contributes to waste reduction and the enhancement of environmental sustainability.

Molybdenum Disulfide–Zinc Oxide Mixed Phase Network as Water Purifier

AbstractThe present work reports the development of oxide‐sulfide hybrid by simple hydrothermal process where zinc oxide (ZnO) prepared by simple chemical process is added in situ during the growth of molybdenum disulfide (MoS2) by hydrothermal process. The as prepared sample is characterized by X‐ray diffraction (XRD), field emission scanning electron microscope (FESEM), and energy dispersive X‐ray analysis (EDX). XRD confirms the coexistence of both ZnO and MoS2 in the sample whereas FESEM shows that fractal kind of sulfide structures get developed over ZnO rod. EDX carries the information regarding the stoichiometry of the sample. The sample is proven to be an excellent remover of textile dyes by synergistic effect of photocatalysis and adsorption with almost 100% efficiency following simple first‐order reaction kinetics. When the porous structure of the sample helps the process of adsorption, the charge transfer mechanism has been assumed to be responsible for photocatalytic dye degradation. The latter involves the transferring of electrons or holes between the photocatalyst and the dye molecules, leading to the generation of reactive species that initiate the degradation process. The combined effect of these two processes takes only 30 min to degrade textile dyes like Bengal rose (BR) and methylene blue (MB). Thus, the present work is supposed to serve as milestone in the associated field.

Voltametric detection of methylene blue dye in water at green and chemically synthesized Ag/MWCNT modified electrode

Abstract A well-known textile dye, methylene blue (MB) was electrochemically detected by using glassy carbon electrode (GCE), modified with green and chemically synthesized silver nanoparticles (AgNPs) decorating the surface of functionalized multiwalled carbon nanotubes (fMWCNT). The green and chemical methods were used to synthesize AgNPs, which decorated MWCNT forming MWCNT/Agchm and MWCNT/Aggrn nanocomposite. Comprehensive characterization of the nanomaterials was carried out using energy-dispersive x-ray spectroscopy (EDX) detector-equipped scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV), and x-ray diffraction (XRD). Using XRD, particle sizes were found to be 26.81, 10.05, 5.36, 19.26, and 17.48 nm for Agchm, Aggrn, MWCNT, Agchm/MWCNT, and Aggrn/MWCNT, respectively. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV) were employed for the investigation of the electrochemical properties and behaviour of MWCNT, Agchm, Aggrn, Agchm/MWCNT, and Aggrn/MWCNT electrodes, and higher electron transport capabilities and improved electrochemical activity towards MB on Agchm/MWCNT electrode were demonstrated by the results. Electroanalysis of methylene blue at the modified electrodes with square wave technique SWV was successful. At Agchm/MWCNT modified electrode, a low limit of detection (LOD) of 4.684 and limit of quantification (LOQ) of 14.194 pM, for MB, while at Aggrn/MWCNT modified electrode , an LOD and LOQ of 2.935 and 8.895 pM, were recorded respectively. In real sample analysis, the recovery percentage for Agchm/MWCNT ranged from 90 to 98% (n =3), and Aggrn/MWCNT showed a recovery percentage ranging from 97 to 103% (n = 3). Both electrodes’ remarkable recovery rate attest to their dependability and sensitivity in MB detection.

Dyeing scheduling optimization in a multi-machine system with resource constraints

Abstract Water consumption is one of the most important concerns for a textile dyeing company in the era of global energy revolution. Different from the traditional production scheduling which focuses on the production efficiency improvement, the dyeing scheduling emphasizes the constraints of resource consumption. Besides, different from the traditional production scheduling where the task relevance is seldomly considered, the colour depth heavily impacts the water consumption and the dyeing scheduling results, which aggravates the uncertainty and complexity when modelling the dyeing scheduling optimization. Therefore, how to select proper dyeing orders among a large number of orders and schedule them for the purpose of generating more profit is challenging. To address the above issue, an optimization model with objective of maximizing profit and consideration of water consumption, delivery due time, and machine capacity, is built, and genetic algorithm is adopted to solve the problem. A numeric experiment is conducted to validate the effectiveness of the proposed method.

A Comparative Study of Congo Red Textile Dye Photodegradation Using ZnO Al and ZnO Al+Mn Nanoparticles

Photodegradation of Congo Red textile dye was successfully carried out using ZnO Al and ZnO Al+Mn nanoparticles synthesized using the bottom-up coprecipitation method. Powder X-ray diffraction provides information that Al and Mn doping successfully inserted in the host crystal structure while maintaining the Hexagonal Wurtzite crystal structure. However, a shift in the diffraction peak caused by the lattice distance changes with the addition of doping. FE-SEM EDS provides information that both nanoparticles are nonuniform sphere-like due to the addition of dopping, and each dopping is detected through EDS spectra. There is a decrease in the gap energy in each sample. ZnO Al nanoparticles have a gap energy of 3.29 eV, and ZnO Al+Mn nanoparticles have a gap energy of 3.28 eV. However, the decrease in the gap energy is not directly related to the percentage and kinetic rate of Congo Red photodegradation. Adding 5 mg of ZnO Al Nanoparticles powder could degrade Congo Red up to 97.9 % within 120 min using UV A radiation or 0.03504/min. At the same time, adding ZnO Al+Mn Nanoparticles powder with the same parameters could only degrade 67.6 % or 0.00759/min. HIGHLIGHTS Energy Bandgap Modification of ZnO Nanoparticles The incorporation of Al single dopants and Al, Mn co-dopants into ZnO nanoparticles synthesized via a bottom-up coprecipitation method significantly alters the energy bandgap. Al single doping resulted in a bandgap of 3.29 eV, while Al, Mn double doping yielded a bandgap of 3.28 eV. Enhanced Photocatalytic Activity of Al-Doped ZnO Al-doped ZnO nanoparticles exhibited superior photocatalytic activity toward the degradation of Congo Red textile dye. With a photodegradation rate constant of 0.03504 min⁻¹, these nanoparticles achieved 97.9 % degradation of Congo Red within 120 minutes. Comparative Photocatalytic Performance of Al, Mn Co-Doped ZnO While Al, Mn co-doped ZnO nanoparticles were synthesized using the same method, their photocatalytic performance for Congo Red degradation was notably lower than that of Al-doped ZnO. The calculated photodegradation rate constant was 0.00759 min⁻¹, resulting in 67.6 % degradation within the same timeframe. GRAPHICAL ABSTRACT

Efficient biodecolorization of direct black 22 Azo Dye by Aspergillus tamarii Kita UCP1279 isolated from caatinga soil

The textile industry is a major consumer of water, generating large volumes of wastewater contaminated with harmful substances, particularly azo dyes, which contain aromatic rings, amines, and sulfonic groups that contribute to their environmental toxicity. The use of microbial agents for wastewater treatment offers a cost-effective and sustainable solution, minimizing sludge production. Fungi from the Caatinga biome have demonstrated potential for bioremediation, especially under extreme environmental conditions. This study explores the ability of Aspergillus tamarii Kita to decolorize the azo dye Direct Black 22 (DB22) under varying conditions, including the use of both active and inactive fungal biomass, in static and agitated systems (120 rpm), at a controlled temperature of 30°C. Dye concentrations of 50, 125, and 250 mg/L were evaluated over time intervals of 75, 180, and 180 minutes, respectively. The influence of dissolved oxygen concentration and redox potential on the decolorization process was also investigated to identify optimal treatment conditions. Decolorization efficiency was quantified via spectrophotometric analysis. Results revealed decolorization rates of 100%, 97%, and 63% for the respective dye concentrations, with active biomass in agitated conditions achieving the highest removal rates. The study further demonstrated that dissolved oxygen levels and redox potential are critical factors in enhancing dye decolorization. These findings underscore the bioremediation potential of Aspergillus tamarii Kita in treating textile dye effluents, offering a promising approach to sustainable industrial wastewater management.

Treatment of textile dyes with steel flakes via Fenton and Electro-Fenton processes: An experimental analysis

The textile production process is well recognised as one of the most water-intensive industries, with an estimated daily water consumption of several thousand cubic metres. The main objective of the study is to remove the colour and COD of three reactive dyes namely reactive blue, reactive yellow and reactive black by Fenton and Electro Fenton Process. In this research paper, new novel catalyst steel flakes have been employed as part of the Fenton and Electro-Fenton process, replacing the conventional Fenton and Electro-Fenton catalyst. Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Analysis (EDAX), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Thermo Gravimetric Analysis (TGA) was done to characterize the steel flakes. The pH, dye concentration, FeSO4 dosage and H2O2 dosage were studied. The maximum colour and Chemical Oxygen Demand (COD) removal in Fenton process was 98.47 % and 74 % respectively. In Electro Fenton Oxidation the maximum colour and COD removal was 99.65 % and 78 % respectively. The best colour and COD removal was observed by Fenton and Electro Fenton oxidation with optimum Fenton molar ratio of 50:1 and pH 3 in all three dyes. In the laboratory-scale feasibility tests on the Electro-Fenton process, the highest colour removal effectiveness was observed at catalyst dosages of 1 g/L, 132 mM H2O2, and pH 3. The novel modified heterogeneous Electro-Fenton approach presents a distinct cost-effectiveness benefit in comparison to both the conventional Electro-Fenton reaction and the Electro-Fenton reaction employing alternative iron sources.

Removal of 4-(2-pyridylazo) resorcinol and Arsenazo-III from liquid waste solutions using Penicillium oxalicum: Gamma irradiation studies

The current investigation involved the isolation of a fungal strain from liquid radioactive wastewater, which was then identified as Penicillium oxalicum and was employed to remove 4-(2-pyridylazo) Resorcinol (PAR) and Arsenazo-III (Ar-III) from liquid waste solutions. The physicochemical properties of the biosorbent fungi were analyzed using SEM and FT-IR. The biosorption effectiveness of PAR and Ar-III was investigated under several experimental settings, including pH values, adsorption times, biosorbent weight, initial dye concentrations, and reaction temperatures. The Langmuir isotherm model describes the adsorption isotherms well, with capacities of 10.88 and 11.96mgg-1 for PAR and Ar-III, respectively. The sorption of PAR and Ar-III exhibited E values of 19.84 and 17.84kJ/mol, respectively, indicating that the process is chemical adsorption. The pseudo-second-order kinetic model was determined as the most accurate representation of the biosorption kinetics. Both film diffusion and intra-particle diffusion describe the diffusion of coloring reagents through the biosorbent material. The thermodynamic analysis showed that chemical adsorption regulated the biosorption of the coloring reagent on the biosorbent material, while exothermic and spontaneous biosorption of PAR and Ar-III was observed. The extensive decolorization and easy operating circumstances demonstrated the promise of Penicillium oxalicum for the biological treatment of textile dyes.

Copper-PANI-graphite HB2 composite for eco-friendly efficient degradation of textile dyes: Advancements in wastewater treatment enhanced by solar radiation

This research aimed to assess the potential of Cu50PANI@UG composite for sunlight drive photocatalytic dye degradation, targeting specifically Thymol Blue (TB) and Black NT (BNT) dyes and their mixture (DM). The Cu50PANI@UG composite was successfully synthesized via electropolymerization in acetonitrile/sulfuric acid mixture under atmospheric conditions. Photocatalytic experiments were conducted by exposing aqueous dye solutions to sunlight. N,N-dimethyl-p-nitrosoaniline (RNO) served as a molecular probe for detecting hydroxyl radicals (•OH). Additionally, experiments capturing free radicals were performed to identify active components, with a concomitant proposal of plausible degradation reaction mechanism for the Photo-Fenton-Like degradation into the Cu50PANI@UG composite + H2O2 + hv reaction system. Various operating parameters affecting dye degradation were evaluated, including catalyst dosage (from 0.27 to 0.67 g L−1), H2O2 concentration (from 16 to 64 mM), pH (from 3.0 to 9.0), and dye concentration (from 25 to 100 mg L−1). Optimization of key parameters such as pH, catalyst dosage, and H2O2 concentration was conducted. The highest degradation efficiency, ca. 100% of DM dye, was achieved within 35 min under optimized conditions, using Cu50PANI@UG composite as a catalytic precursor. These conditions were determined as follows: Catalyst dosage = 0.67 g L−1, pH = 3.0–6.0, H2O2 = 32–64 mM, and irradiation time of 35 min. The degradation percentage under the Response Surface Methodology (RSM) was utilized as a statistical tool to correlate influential parameters. Four consecutive reusability trials were performed to assess catalyst stability.

Fe3O4/sugarcane bagasse magnetic composite: A low-cost and green adsorbent for enhanced adsorption of Rhodamine B from aqueous solutions

In this study, we have designed and synthesized an eco-friendly Fe3O4/sugarcane bagasse magnetic composite (Fe3O4/SCB). We investigated its application for efficiently removing Rhodamine B (RhB) from textile wastewater, a significant step towards addressing the environmental issue of textile dye pollution. The composite, made from sugarcane bagasse (SCB), a secondary product from the sugarcane industry, proved an effective adsorbent. The composite Fe3O4/SCB was characterized by PXRD, FT-IR, FE-SEM, VSM, BET N2 adsorption-desorption, and pHpzc. Results from batch adsorption studies show that the removal of RhB was 93.6 ± 1.16 % using a composite dose of 1 g/L, a RhB concentration of 10 mg/L, a contact period of 60 min, and a solution pH of 3 at 323 K of solution temperature. The kinetic studies indicate that the pseudo-second-order model most accurately describes the adsorption. Meanwhile, the equilibrium data is well-represented by the Freundlich isotherm. Further, the analysis of thermodynamic results, such as the changes in ∆Go, ∆So, and ΔHo, revealed that the adsorption was spontaneous, feasible, and endothermic. The adsorption mechanism involved chemisorption and physisorption, with significant roles played by electrostatic interactions and hydrogen bonding. Desorption studies identified 0.5 M NaOH as an effective desorbing agent, and the composite demonstrated excellent reusability over four adsorption-desorption cycles. Overall, the Fe3O4/SCB, with its easy preparation, abundance, cost-effectiveness, efficiency, and eco-friendly nature, presents a promising solution for effectively removing toxic RhB from aqueous solutions, inspiring further research and potential real-world applications.