Simple and eco-friendly synthesis of octahedral MnFe2O4 using green tea and application in congo red dye adsorption

NiO nanoparticle doped-PVA-MF polymer nanocomposites: Preparation, Congo red dye adsorption and antibacterial activity

Editorial

Synthesis, Characterization and Evaluation of Thermal, Adsorption and Antioxidant Studies of Amino Functionalized Poly(methyl methacrylate)/Titanium dioxide Nanocomposites

A comprehensive study combining experimental, computational, and field experiments was conducted to find out the most suitable catalysis method to assist industries using Congo red dye to get rid of this waste from industrial wastewater in Beni-Suef area. The adsorption potential of kaolinite, Liagora farinose (Egyptian marine macroalgae) and kaolinite modified by Liagora farinose macroalgae assessed for the removal of Congo red dye from aqueous solutions. The kaolinite/alga nano-composite with a crystal size of 40 nm was fabricated using a wet impregnation technique. Our results indicate that surface modification of kaolin with Liagora farinose results in an obvious increase in adsorption of toxic dye for nano-composite than individuals. Batch experiments were applied and both kinetics and isotherms of Congo red dye adsorption were also explored in order to find out the influence of different experimental factors. Congo red removal percentage is highly affected by adsorbent dose, working temperature, and pH value. The best temperature for Congo red adsorption onto kaolinite/alga nano-composite is 40°C at pH > 7. The maximum adsorption capacities were found to be 5.0, 7.0 and 10 mg/g for kaolinite, alga and kaolinite/alga nano-composite, respectively. Computational simulations studies have shown that the adsorption of the Congo red molecule on Kaolinite surfaces is exothermic, energetically favourable and spontaneous. Congo red adsorption on kaolinite/alga nano-composite is well handled with the first-order diffusion model, while kaolin and Liagora farinose follow two different kinetic adsorption models depending on the Congo red dye concentration. Finally, the field tests showed optimistic results with nearly 94% efficiency for kaolinite/alga nano-composite in removing mixed dyes from industrial wastewater, which in turn verified the foundation of new eco-friendly nano-adsorbents to help reuse industrial wastewater.

The recent interest in adsorption of pollutants on nanomaterials has been gaining widespread attention especially in the utilization of nanocarbon based composite materials. Herein, graphene oxide/silica/single-wall carbon nanotubes (GO/SiO2/SWCNTs) composite was successfully prepared by a hydrothermal method for the adsorption of Congo red (CR) dye from synthetic wastewater. The nanocomposite morphology was characterized by X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), and Energy-dispersive X-ray spectroscopy (EDX). The present study focuses on the adsorption performance of CR dye from aqueous solution on GO/SiO2/SWCNTs composite in terms of kinetics, isotherm, thermodynamics studies and optimization of factors such as pH, temperature, concentration and adsorption time. The results showed that a higher adsorption of CR was observed onto GO/SiO2/SWCNT composite at pH 3.0 as compared to that with SiO2 and SWCNT. Similarly, the maximum adsorption capacity of 456.15 mg g−1 was achieved at optimum temperature 20 °C, time (330 min) and 300 mg L−1 CR solution concentration. The dye adsorption on the nanocomposite was found to be obeying pseudo-second-order rate equation. Thermodynamic parameters showed that the adsorption of CR dye was spontaneous in nature.

Nanovertenergie: Bactericidal polymer nanocomposite beads for carcinogenic dye removal from aqueous solution

The study of the Congo red dye adsorption was performed using LaMnO3 and LaNiO3 perovskites-type obtained by mechanosynthesis. The synthesized perovskites were characterized by thermogravimetric analysis, Fourier Transform Infrared (FTIR) absorption spectroscopy, X ray diffraction patterns (XRD) and N2 adsorption at −196 °C. The adsorption efficiency of the perovskites in the Congo red adsorption was evaluated. The nickel-based sample showed a maximum adsorption efficiency of 48%, while the manganese-based material showed a maximum efficiency of 73%. Kinetic studies showed that the pseudo-second order model was the most appropriate to describe the experimental values, as it showed R2 values closer to the unit. It was possible to recover the adsorbent that could be reused after the adsorption assays.

Development of CTAB modified ternary phase α-Fe2O3-Mn2O3-Mn3O4 nanocomposite as innovative super-adsorbent for Congo red dye adsorption

Purpose – The purpose of this paper is to focus on the removal of Congo red dye from aqueous solution using magnetically separable novel adsorbent prepared by coating activated charcoal on magnetic nanoparticles. Design/methodology/approach – The synthesized magnetic nanocomposite of activated charcoal was characterized using Fourier transform infra-red (FTIR), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) analysis. The removal of Congo red from aqueous solution using magnetic nanocomposite of activated charcoal was optimized. The equilibrium and kinetics modeling of adsorption of Congo red was analyzed. Findings – The presence of activated charcoal on magnetic nanocomposite was confirmed by FTIR analysis. The average size of the nanocomposite was found to be 12.77 nm using SEM characterization. The elemental composition by EDS analysis confirmed the increase in concentration of carbon due the adsorption of Congo red dye. The optimum conditions for batch adsorption was found to be 1 g/L of adsorbent, dye concentration 50 mg/L, pH 3 and temperature 70°C. The adsorption of Congo red dye on magnetic nanocomposite of activated charcoal was found to follow Temkin adsorption isotherm. Originality/value – The experimental data were found to fit well with the pseudo second-order kinetics and the rate of adsorption was found to be controlled by intra-particle diffusion.

ABSTRACTThis study investigates the adsorption of Congo red dye on walnut shell powder based activated carbon in batch process (WNAA). Walnut shell powder was carbonized by treating with phosphoric acid (H3PO4), and the adsorbent was characterized using Fourier Transform-Infrared spectrophotometer (FT-IR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), and pH point of zero charge (pHpzc), respectively. Operational parameters such as contact time, initial dye concentration, and pH were investigated using batch-adsorption techniques. The adsorption uptake was found to increase with increase in initial dye concentration and contact time. The optimum CR dye uptake was observed at pH 3.12 corresponding to 94.53% removal. Pseudo-first-order, pseudo-second-order, Elovich, and Intraparticle diffusion kinetic models were used to test the adsorption data. The pseudo-second order exhibited the best fit out of the four kinetic models used. Equilibrium data were fitted to the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models. Langmuir model fitted the adsorption data most with maximum monolayer coverage of 40 mg/g. Thermodynamic parameters such as Gibbs free energy, enthalpy, entropy, and the activation energy were determined. It was found that Congo red dye adsorption was spontaneous and endothermic. 0.02M Hydrochloric acid was used to regenerate the adsorbent prepared, and the regenerated adsorbent was used for dye adsorption. Congo red dye adsorption capacity ranged from 90% to 93% at three consecutive times. This study has shown that walnut shell is a good adsorbent in the treatment of Congo red dye from aqueous solutions.

Lignite is easily oxidized, and spontaneous combustion occurs during its storage, which greatly reduces its calorific value and affects its quality and economic benefits. The surface properties of the oxidized lignite including pore structure and oxygen-containing functional groups were investigated by N2 adsorption/desorption isotherms and Fourier transform infrared spectroscopy. The adsorption of Congo red dye in aqueous solution by oxidized lignite was carried out. It was observed that due to oxidation, the specific surface area and total pore volume of the Huolinhe lignite samples decreased, and the average pore size increased. As oxidation temperature increased, the number of microporous and mesoporous structures decreased, resulting in the decrease of fractal dimension. The hydroxyl content was negatively correlated with the oxidation temperature, but the carbonyl content showed an opposite trend. At the initial stage of oxidation, the rate of hydroxyl consumption is higher than that of formation. The reaction to generate carbonyl, such as the oxidation of aliphatic hydrocarbons, alcohol hydroxyl groups and ethers, requires a higher reaction temperature, so the carbonyl content increased when the temperature was higher than 70 °C. Oxidized lignite was used to adsorb Congo red dye in aqueous solution, and the removal increased significantly with increasing oxidation temperature. Therefore, oxidized lignite can effectively remove Congo red dye from aqueous solution, so as to improve the economic benefit of oxidized lignite.

ABSTRACTThis study investigates the adsorption of Congo red (CR) dye onto corn cob based activated carbon (CCAC) in the batch process. The activated carbon was characterized using FTIR, SEM, and EDX techniques, respectively. The effect of operational parameters such as the initial dye concentration (10–50 mg/L), contact time (5–160 minutes), and solution temperature (30–50°C) were studied. The amount of the CR dye adsorbed was found to increase as these operational parameters increased. Kinetic data for CR dye adsorption onto CCAC were best represented by the pseudo second-order kinetic model. Four different isotherms namely Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models were used to test the adsorption data. It fitted the Langmuir isotherm model most. Thermodynamic parameters such as ΔH0, ΔS0, and ΔG0 were evaluated. The adsorption process was found to be exothermic and spontaneous. The study shows that CCAC is an effective adsorbent for the adsorption of CR dye from aqueous solution.

One of the most significant applications of green chemistry is the utilization of agricultural organic waste products as efficient and cost-effective adsorbents. This eventually leads to environmental sustainability and the safeguarding of natural resources. Previous studies have shown that many agricultural waste products may be used as source materials or with physical or chemical alterations in Congo red (CR) dye adsorption. Employing waste materials aligns with the concepts of sustainability and waste reduction, both of which are important aspects of green chemistry. Agricultural waste is often abundant and inexpensive, making it a viable alternative to conventional adsorbents. Transforming debris into usable commodities reduces the environmental effect of waste disposal and the demand for non-renewable resources. Many agricultural wastes have vast surface areas and functional groups, which can effectively adsorb pollutants from aqueous solutions. This mini-review looks at the use of organic waste materials such as agricultural leftovers, fruit peels, and biomass as sustainable adsorbents to remove the hazardous color Congo Red from water. It emphasizes the benefits of these materials over traditional adsorbents, looking at advances in their manufacture and modification to increase adsorption capacity. The review analyses the parameters that influence the adsorption process, compares green adsorbents to traditional ones, and considers their regeneration and reuse, highlighting their potential for environmental conservation and waste valorization.

The removal of pollutants from water bodies is crucial for the well-being of humanity and is a topic of global research. Researchers have turned their attention to green synthesized nanoparticles for wastewater treatment due to their eco-friendly nature, biocompatibility, and cost-effectiveness. This work demonstrates the efficient removal of organic dye and both gram-positive and gram-negative bacteria from water bodies using copper-doped cerium oxide nanoparticles synthesized with Murraya Koenigii extract. Characterized via various methods, the 15% copper doped cerium oxide nanoparticles (Cu 15% NPs) exhibited maximum Congo red dye adsorption (98% degradation in 35 min). Kinetic analysis favoured a pseudo-second-order model, indicating the chemical nature of adsorption. Equilibrium adsorption isotherms aligned with the Langmuir model, indicating homogenous monolayer dye adsorption on the doped adsorbent. The maximum uptake of adsorbate, Q m obtained from Langmuir model for Cu 15% NPs was 193 mg g−1. The study also showed enhanced antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa for Cu-doped ceria, attributed to generation of reactive oxygen species (ROS) induced by the redox cycling between Ce3+ and Ce4+. This substantiated that the green synthesized copper doped cerium oxide nanoparticles are potential candidates for adsorptive removal of Congo red dye and as antibacterial agents.

Optimized adsorption and effective disposal of Congo red dye from wastewater: Hydrothermal fabrication of MgAl-LDH nanohydrotalcite-like materials