Removal Of MB Dye Research Articles

Utilization of poplar fibers in needle punched nonwovens

The focus of this study is to conduct pioneering research on utilizing poplar seed hair fibers in needle punched nonwovens. These fibers were blended with hollow PET fibers at two different weight ratios to obtain needle punched webs for the first time. The weight, thickness, abrasion resistance, bursting and tensile properties, hydrophobic/oleophilic surface characteristics of the nonwovens are analyzed elaborately. Finally, it has been demonstrated that poplar fiber-containing nonwovens have superior rose oil absorption compared to solely PET nonwoven fabrics. When compared the maximum adsorption capacities, the incorporation of 37.3 wt.% and 21.7 wt.% poplar fiber into PET nonwoven increased the oil absorption by approximately 35 and 24 times, respectively. Although pristine PET nonwoven was able to remove only 16% of MB dye from aqueous dye solution, addition of poplar fiber enhanced the removal process and the solution had been decolorized to nearly colorless. The results indicated that poplar blended nonwoven fabrics treated with NaClO2 show the high-performance removal of MB dye from wastewater, with the increased percentage of 40% and 67% for PET-PO30 and PET-PO60 fabric, respectively. Therefore, developing industrial scale surfaces with non-traditional and sustainable poplar seed fibers, marks a significant advancement for the textile industry.

Porphyrin like porous fullerene functionalized with Ga as an effective adsorbent for the removal of methylene blue from wastewater effluent

Removal of dyes is a significant aspect of environmental remediation to ensure clean water and atmosphere. In this study, we report Ga decorated porphyrin like porous fullerene (Ga@C24N24) for effective removal of cationic dye (methylene blue) using density functional theory calculations. The calculations show that the Ga are strongly anchored at the surface of the C24N24 system with stronger binding energies and larger positive charges. The molecular dynamics simulations evince that the Ga@C24N24 are thermally stable and withstand high temperatures as 500K. The application of Ga@C24N24 as adsorbent for the removal of MB dye shows that the dye could strongly adsorbed over the Ga@C24N24 surface with stronger electrostatic covalent bonds and larger adsorption energies (-2.71 and -1.89 eV for MB@Ga-C24N24 from N site and S site) compared to bare C24N24 system. The electron density difference, partial density of states, and atom in molecule analysis give evidence of the presence of stronger electrostatic covalent bonds between the Ga@C24N24 and MB. This stronger bonding leads to the chemisorption of MB over the Ga@C24N24 surface. The maximum uptake capacity analysis shows that the studied adsorbent can successfully adsorbed 6MB molecules. The solvation effect decreases the desorption time of the MB molecules from Ga@C24N24. These results show that this study will help the experimentalists to explore the Ga@C24N24 system as a new metalloid doped adsorbent for the removal of toxic pollutants from wastewater.

Ultrasonication-assisted synthesis of CuO-decorated montmorillonite K30 nanocomposites for photocatalytic removal of emerging contaminants: A response surface methodology approach

Environmental pollution is increasing worldwide due to population and industrialization. Among the various forms of pollution, water pollution poses a significant challenge in contemporary times. In this study, we synthesized CuO-decorated montmorillonite K30 (MK30) nanosheets via a simple ultrasonication technique. The structural, morphological, compositional, and optical properties of the synthesized nanocomposites were evaluated using advanced instrumentation techniques. The morphology of CuO was cubic and cubic CuO evenly designed on the MK30, which was proved by Field Emission Scanning Electron Microscopy (FESEM). The adsorption photocatalytic activity of the synthesized cubic CuO/MK30 composites was examined through the degradation of MB under visible light irradiation. The apparent reaction rate constant of 20% CuO/MK30 was 12.5 folds higher than that of CuO. These conditions included a catalyst dosage ranging from 5 to 15 mg, a pH level ranging from to 3–11, and a pollutant concentration ranging from 5 to 20 mg/L. The optimal conditions for MB dye removal were determined using response surface methodology (RSM). A scavenger study of the composite was conducted and verified that •O2− and •OH radicals play an important role in the degradation process. This investigation addressed the process of adsorption and potential removal pathways, with a particular emphasis on the role of functional groups. The environmentally friendly CuO/MK30 nanocomposites exhibited potential as photocatalysts for efficiently absorbing and degrading MB dye and TC drug pollutants. They represent promising candidates for the treatment of industrial wastewater, aiming to mitigate the environmental threats posed by organic pollutants.

Hydrothermally synthesized Nb -doped TiO2 nanosheets for efficient removal of methylene blue dye on photocatalytic performance

In this work, Niobium-doped (1%, 3%, and 5%) titanium dioxide (Nb-TiO2) nanosheets were successfully formed via the hydrothermal route and further characterized using TEM, XRD, XPS and UV–vis absorption spectroscopy techniques. Phase purity and structural information of the prepared materials were analysed by XRD measurements. The band gap values ranged from 3.27 to 2.98 eV as Nb doping increased, leading to improved photocatalytic activity by creating new energy levels close to the conduction band. The XPS results confirm the amalgamation of Nb5+ ions into TiO2 without affecting the crystallinity, structure or orientation of the occurrence of oxygen vacancies. In 3% Nb-doped TiO2, the degradation efficiency for removing (Methylene blue) MB dye increased by ∼96% for the removal of MB dye within 70 min in comparison to pure and other doped TiO2 catalysts The better photocatalytic activity of 3% Nb-TiO2 is due to the longer time between electron–hole pairs before they recombine into one pair. Hydroxyl radicals (HO•) and superoxide radicals (O2 •−) are the primary reactive entities responsible for the deterioration of MB dye. Therefore, incorporating Nb into TiO2 nanostructures represents an auspicious material for the decomposition of hazardous and toxic pollutants in aquatic environments.

Photocatalytic activity of ZnO doped Nano hydroxyapatite/GO derived from waste oyster shells for removal of Methylene blue.

Hydroxyapatite (HAp) stands as an inorganic compound, recognized as a non-toxic, bioactive ceramic, and its composition closely resembles that of bone material. In this study, nHAp was prepared from waste oyster shells, which are biowaste rich in calcium carbonate. nHAp with its unique catalytic property can be used as an adsorbent in various fields, including wastewater treatment. nHAp with an exceptional surface adsorbent with excellent chemical stability, enabling its catalytic function. Nano hydroxyapatite doped with Zinc oxide (ZnO) by wet chemical precipitation and made into a composite with Graphene oxide (GO) by modified hummers method followed by grinding, which was taken as 9:1 ratio (nHAp/ZnO and GO) of weight, enhances its tensile and mechanical strength. The energy band gap of nHAp photocatalyst was evaluated as 3.39eV and that of the in nHAp/ZnO/GO photocatalyst was narrowed to 1.77eV. The ternary nanocomposites are very efficient in generating the photogenerated electrons and holes, thereby improving the degradation potential of dye effluents to by-products such as CO2 and H2O. The nanocomposites photocatalyst were characterized by FTIR, XRD, SEM, TEM, EDS, XPS, DRS, and BET techniques. The UV-visible study shows the complete dye degradation efficiency of the prepared nanocomposites photocatalyst. In this study, the prepared nanocomposites nHAp/ZnO/GO have studied their efficiency for the removal of MB dye in a batch process by varying the dosage from 0.1 to 0.5g, and the effects of dosage variations, pH, kinetic, scavenger study were evaluated at a time interval of 30min. The removal of dye was found to be 99% at 150min of 0.3g dosage and pH = 12 is most favorable as it reached the same percentage at 90min. The as-prepared nanocomposite nHAp/ZnO/GO fits the kinetic rate constant equation and shows a pseudo-first-order reaction model. This study indicates the suitability for dye removal due to the synergistic effect and electrostatic interaction of the synthesized ternary nanocomposite, which shows the potential, socially active, low-cost-effective, eco-friendly, and safe for photocatalytic degradation of MB from wastewater.

A novel composite (Bi2WO6/TiS2) presenting an excellent Z-scheme photocatalytic degradation for methylene blue dye under the visible light irradiation

The current research direction in the field is the development of a Z-scheme composite photocatalyst for the purpose of degrading organic materials in water. The Solvo-thermal synthesis method was employed to successfully synthesize a novel Z-scheme photocatalyst namely Bi2WO6/TiS2@3 %, Bi2WO6/TiS2@6 % and Bi2WO6/TiS2@9 % which is driven by visible light. The materials physicochemical properties were assessed using several analytical methods i.e. XRD, EDX, SEM, TEM, FTIR, UV–vis, PL, Raman spectroscopy and EIS. The Bi2WO6/TiS2@6 % composite revealed the maximum photocatalytic efficiency in the removal of MB dye (98 %) in 70 min. The results of the free radical trap studies indicate that h+ and •O2− are the primary free radicals involved in the photocatalytic degradation. The photocatalytic performance of the composite was improved due to the creation of a heterojunction between Bi2WO6 and TiS2 resulted in enhanced electron conduction, efficient separation of photogenerated e- and h+. Furthermore, it has been shown through six cycle test that the hybrid material consisting of Bi2WO6/TiS2@6 % exhibited a consistent degrading capability (91 %) during the photodegradation process. This distinctive heterojunction photocatalyst material exhibits extensive potential for application in the elimination of organic contaminants and cleanup of the environment.

Investigation of kinetics and thermodynamics of methylene blue dye adsorption using activated carbon derived from bamboo biomass

This research paper aimed to evaluate the potential of activated carbon (AC) made from non-torrefied and torrefied bamboo biochar samples for the purpose of adsorbing methylene blue solution. The process involved impregnating bamboo biochar with a 5 M potassium hydroxide (KOH) solution at a 1:4 ratio of biochar to KOH, followed by carbonization at 800 °C, 900 °C, and 1000 °C to produce activated carbon samples. The samples were then characterized using techniques such as XRD, FESEM-EDX, FTIR, FE-TEM, and BET analysis to study their respective phase, surface morphology, elemental composition, functional groups, and structural and surface properties. The results showed that the torrefied bamboo AC exhibited a specific surface area of 366 m2/g and a total pore volume of 0.24 m3/g. Kinetic analyses showed adsorption following a pseudo-second-order model, with a capacity of 83.3 mg/g according to the Langmuir model and a favorability constant of 0.52 from the Freundlich model. Thermodynamic studies revealed the process to be spontaneous and endothermic, with changes in enthalpy and entropy of 77,810.73 kJ/mol and 269.9 kJ/mol·K, respectively. These findings highlight the effectiveness of bamboo-derived AC as a sustainable adsorbent for MB dye removal, offering a promising solution for water pollution control.

Adsorption behavior of MB dye on alginate-sepiolite biocomposite beads: Adsorption, kinetics, and modeling

This work is based on the preparation of biocomposite beads Alginate-Sepiolite using a simple preparation method. A series of materials was prepared by varying only the mass of the sepiolite in the biocomposite beads (mass of the sepiolite is varied between 0.5–1.5 g in the reaction mixture). The obtained biocomposites were characterized by XRD, FTIR, TGA, XRF, SEM, and EDX and then tested as adsorbents for the removal of Methylene Blue MB dye in an aqueous solution. To study the adsorption behavior of MB dye on biocomposites, several parameters affecting MB adsorption were investigated and discussed. The results obtained showed that the ALG-Sep composite hydrogels were well formed, and their properties were improved depending on the sepiolite content used. The kinetics and modeling results show that the adsorption process follows first-order kinetics, and the Langmuir model. It was found that the adsorption capacity of MB dye increased with the increase of sepiolite in the composite beads, and adsorption was carried out in the following order ALG-Sep(1.5) > ALG-Sep(1) > ALG-Sep(0.5). The maximum absorption capacity of MB dye on ALG-Sep(1.5) was qmax = 55.49 mg.g−1. Among the advantages of this biocomposite is that it is prepared from natural and non-toxic sources, and it is easily separable after adsorption, which makes it an excellent candidate for the elimination of organic pollutants in polluted waters.

Valorization of agroindustrial orange peel waste during the optimization of activated carbon–multiwalled carbon nanotubes–zinc oxide composites used in the removal of methylene blue in wastewater

Activated carbons (AC) produced from agroindustrial orange peel (OP) wastes and/or commercial multi–walled carbon nanotubes (MWCNTs) were modified with ZnO nanoparticles in different amounts (15 and 30 wt–%) for the removal of methylene blue in aqueous solutions. The MWCNTs functionalization was carried out by typical procedure in acid medium using a ratio of 3:1 (HNO3/H2SO4). A batch adsorption analysis was carried out evaluating different parameters: MB concentration from 40 to 100 mg L–1; pH values between 4 and 10 and adsorption time that varied from 1 to 48 h. The modified materials were characterized through the techniques XRD, FTIR, BET, TGA, SEM and UV–vis. The results showed an adequate dispersion of ZnO NPs on the carbon surfaces with a typical flower–like morphology this type of shape developed micropores that facilitate adsorption phenomena. Under the evaluation conditions, 20 mg of carbon–based materials can remove up to 89.5 ± 4.47 % of MB (80 ppm) after 24 h of exposure at a regulated pH of 8. The equilibrium adsorption data were better fitted by a Langmuir isotherm (R2 = 0.9999) than the Freundlich model (R2 = 0.9366); showing in the best case a maximum adsorption capacity of 1250 mg g−1 for both materials with 30 wt–% of ZnO NPs (AC–MWCTs or MWCNTs). Experimental data also suggest that the most likely mechanism is chemisorption followed by physical adsorption. Then, the compounds with 30 wt–% metal loading (ZnO NPs), AC–MWCNTs–ZnO or MWCNTs–ZnO, displayed the most interesting properties for MB dye removal. AC–ZnO compounds can also remove about 88.75 ± 4.43 % of MB, demonstrating that it can also be a facile and low–cost method to improve the surface area in carbonaceous structures by promoting a strong interaction with the ZnO NPs, which in turn helps to remove contaminants in water efficiently.

A green and economic approach to synthesize magnetic Lagenaria siceraria biochar (γ-Fe2O3-LSB) for methylene blue removal from aqueous solution.

In the printing and textile industries, methylene blue (a cationic azo dye) is commonly used. MB is a well-known carcinogen, and another major issue is its high content in industrial discharge. There are numerous removal methodologies that have been employed to remove it from industrial discharge; however, these current modalities have one or more limitations. In this research, a novel magnetized biochar (γ-Fe2O3-LSB) was synthesized using Lagenaria siceraria peels which were further magnetized via the co-precipitation method. The synthesized γ-Fe2O3-LSB was characterized using FTIR, X-ray diffraction, Raman, SEM-EDX, BET, and vibrating sample magnetometry (VSM) for the analysis of magnetic properties. γ-Fe2O3-LSB showed a reversible type IV isotherm, which is a primary characteristic of mesoporous materials. γ-Fe2O3-LSB had a specific surface area (SBET = 135.30 m2/g) which is greater than that of LSB (SBET = 11.54 m2/g). γ-Fe2O3-LSB exhibits a saturation magnetization value (Ms) of 3.72emu/g which shows its superparamagnetic nature. The batch adsorption process was performed to analyze the adsorptive removal of MB dye using γ-Fe2O3-LSB. The adsorption efficiency of γ-Fe2O3-LSB for MB was analyzed by varying parameters like the initial concentration of adsorbate (MB), γ-Fe2O3-LSB dose, pH effect, contact time, and temperature. Adsorption isotherm, kinetic, and thermodynamics were also studied after optimizing the protocol. The non-linear Langmuir model fitted the best to explain the adsorption isotherm mechanism and resulting adsorption capacity ( =54.55mg/g). The thermodynamics study showed the spontaneous and endothermic nature, and pseudo-second-order rate kinetics was followed during the adsorption process. Regeneration study showed that γ-Fe2O3-LSB can be used up to four cycles. In laboratory setup, the cost of γ-Fe2O3-LSB synthesis comes out to be 162.75 INR/kg which is low as compared to commercially available adsorbents. The results obtained suggest that magnetic Lagenaria siceraria biochar, which is economical and efficient, can be used as a potential biochar material for industrial applications in the treatment of wastewater.

Synthesis and characterization of a new natural saccharide polymer (n-LTP) for adsorption of Methylene blue dye from an aqueous solution

ABSTRACT In this study, a new natural polysaccharide material, i.e., n-LTP, was synthesized by mixing Linum usitatissimum seed oil cake, Trigonella foenum-graecum and Plantago physilium husk in a 1:1:1 ratio for adsorption of Methylene blue. BET, FTIR and SEM reveal the presence of various organic and inorganic groups besides heterogeneous surfaces of the adsorbent having a surface area of 384 m2/g. It is observed that at pH values of 12, contact time of 100 min, n-LTP dose of 1.5 mg, with dye concentration of 70 ppm at 50 °C, nearly 88% of adsorption take place. Experimental data shows that the Freundlich isotherm (R2 = 0.96) and pseudo-first-order kinetic model (R2 = 0.9538) fit best to the process. A thermodynamic study showed that the process was spontaneous, endothermic and feasible. Electrostatic, π -π and hydrogen bonding interactions are involved in MB dye adsorption on n-LTP as confirmed by a surface complexation model (SCM). Overall, results of the study explored the potential f n-LTP for removal of MB dye from contaminated water. This study is novel as till now, to the best of our knowledge, no work has been reported on MB adsorption using n-LTP as Q5 an adsorbent specifically.

Chitosan‐nTiO2 Nanocomposite Synthesis and its Adsorptive Removal Capacity for Methylene Blue from its Aqueous Solution: Batch Adsorption Study and Modeling

AbstractThe current work used chitosan (CS)‐nTiO2 nanocomposites (CTNCs) prepared with different CS:nTiO2 mass ratios toward the MB dye removal from an aqueous medium in batch method at variable experimental conditions. The stability and competence of the nanocomposites were checked through characterization by SEM, FTIR, XRD, TGA, and BET. The highest removal of MB was 78 % with the adsorbent CS without nTiO2 (CWT), 94.5 % with CS:nTiO2=1 : 1 weight ratio (CTNC1‐1) and 80 % with CS:nTiO2=2 : 1 weight ratio (CTNC2‐1) with 10 mgL−1of MB and 5 gL−1 adsorbent dosages. The experimental observations obeyed the pseudo‐2nd‐order model, and rate‐limiting steps were film diffusions for CWT, CTNC1‐1 and intraparticle diffusion for CTNC2‐1. Monolayer adsorption was established from the isotherm model. Langmuir adsorption capacities for MB were presented as CTNC1‐1 (qL=34.31)>CTNC2‐1 (qL=32.87)>CWT (qL=21.32). The sorption energy, as derived from Dubinin–Radushkevich isotherm model, showed physisorption for all three adsorbents. The scale‐up design is reported. The statistical (R2>0.98) and GA modeling (R2>0.98) successfully predicted the percentage elimination of MB. Thus, CS‐nTiO2 nanocomposites are prepared as novel and environment‐friendly adsorbents for dye removal.

Advancing the eradication of harmful dyes through stereolithography-produced 3D floating photocatalysis: Exploiting the synergistic potential of graphene/MnO2/Fe3O4 hybrid nanomaterials

The utilization of heterogeneous photocatalysis for the breakdown of organic pollutants in wastewater has become increasingly popular as an alternative treatment method, offering rapid mineralization of organic compounds. However, the challenges lie in the recycling and recovery processes. To overcome this hurdle, a novel 3D-printed hybrid photocatalyst composed of graphene/MnO2/Fe3O4 was developed through an ex-situ approach. Comprehensive property evaluations were conducted, and the catalyst was employed in the creation of a 3D photocatalyst designed for MB dye removal under direct sunlight, facilitating the easy separation of the used catalyst. Further enhancement of its photocatalytic activity was achieved through carbonization, rendering it promising for wastewater treatment owing to its ordered structure and facile recovery. Notably, the developed 3D photocatalyst exhibited a significant improvement in MB dye degradation compared to powder samples. It showcased effective degradation of 10 ppm of MB dye within a mere 120 min of sunlight exposure. Radical trapping analysis indicated that the high photocatalytic degradation was predominantly attributed to the photogenerated superoxide radicals. Consequently, the 3D printed photocatalyst demonstrated exceptional reusability and sustained efficiency in MB dye degradation without any discernible decrease in catalytic activity. The augmented photocatalytic degradation was governed by the generation of photogenerated charge carriers through reduction and oxidation reactions. This research holds promise for the creation of an economical, user-friendly, and highly efficient 3D printed hybrid photocatalyst with synergistic applications in water purification.

Removal of methyl blue from aqueous solutions with nano-magnetic Pinus brutia biochar

In the study, the removal of dye (methyl blue) from aqueous solutions by batch/agitation adsorption method was investigated using Pinus brutia (PB). For this purpose, first, PB wood was collected and made into wood chips (PB), and then Pinus brutia biochar (PBB) was made. The PBB was modified to gain nano-magnetic properties. The biochar structure was characterized by FT-IR. PBB and nM-PBB were used for the removal of MB dye. The adsorbent amount, temperature, pH, time and dye concentration were investigated in the adsorption process with adsorption isotherms, kinetics and thermodynamics to estimate their MB removal efficiency. Sorption equilibrium for MB dye was reached by nM-PBB within 60 min and adsorption efficiency up to 99.007% was reached. While the adsorption kinetics followed a pseudo-second-order kinetic model, the Langmuir isotherm model, with a maximum adsorption capacity of 107.527 mg/g (nM-PBB), showed homogeneous physiochemical adsorption. The efficiency was found to be a spontaneous endothermic reaction. It can be suggested that nM-PBB can be used to remove MB.

Adsorption of methylene blue dye onto phosphoric acid-treated pomegranate peel adsorbent: Kinetic and thermodynamic studies

The orthophosphoric acid-treated pomegranate peels (POPAC) performance was investigated through batch mode for Methylene Blue dye (MB) adsorption from an aqueous solution. Although chemical activation using various chemical agents has been explored by other research work, but novelty application of H3PO4 in a 1:1 wt percentage for activation exhibits unprecedented performance in enhancing the efficiency of MB dye removal. Dependent parameters were optimized, with pH of the sample, contact interval, initial MB concentration, and dose of adsorbent. Excellent removal efficiency (above 92 %) was observed at pH 8 with a dose of 0.25 g/100 mL for 120 min of contact duration. At the qmax value of 14.03 mg/g, the Langmuir isotherm demonstrated the MB dye monolayer adsorption onto POPAC, elucidating the adsorption mechanism with R2 = 0.9883. The kinetics of MB adsorption fit excellently through the pseudo-second-order model with R2 = 0.9997, and the model's estimated adsorption capacity agreed well with the results obtained from the experimental investigation. Thermodynamic parameters, including ΔGᵒ, ΔH°, and ΔS°, additionally demonstrated the spontaneous as well as endothermic adsorption nature of MB on the POPAC’s surface. Furthermore, regeneration studies using 0.1 M NaOH and 0.1 M HCl solutions show adequate MB dye elimination after three cycles. According to the research findings, pomegranate peel may be an inexpensive, environmentally acceptable, and operative biosorbent to eliminate MB dye from polluted aqueous matrices.

Fabrication of cellulose nanocrystals/carboxymethyl cellulose/zeolite membranes for methylene blue dye removal: understanding factors, adsorption kinetics, and thermodynamic isotherms.

This study introduces environmentally-friendly nanocellulose-based membranes for AZO dye (methylene blue, MB) removal from wastewater. These membranes, made of cellulose nanocrystals (CNCs), carboxymethyl cellulose (CMC), zeolite, and citric acid, aim to offer eco-friendly water treatment solutions. CNCs, obtained from sugarcane bagasse, act as the foundational material for the membranes. The study aims to investigate both the composition of the membranes (CMC/CNC/zeolite/citric acid) and the critical adsorption factors (initial MB concentration, contact time, temperature, and pH) that impact the removal of the dye. After systematic experimentation, the optimal membrane composition is identified as 60% CNC, 15% CMC, 20% zeolites, and 5% citric acid. This composition achieved a 79.9% dye removal efficiency and a 38.3mg/g adsorption capacity at pH 7. The optimized membrane exhibited enhanced MB dye removal under specific conditions, including a 50mg adsorbent mass, 50ppm dye concentration, 50mL solution volume, 120-min contact time, and a temperature of 25°C. Increasing pH from neutral to alkaline enhances MB dye removal efficiency from 79.9% to 94.5%, with the adsorption capacity rising from 38.3mg/g to 76.5mg/g. The study extended to study the MB adsorption mechanisms, revealing the chemisorption of MB dye with pseudo-second-order kinetics. Chemical thermodynamic experiments determine the Freundlich isotherm as the apt model for MB dye adsorption on the membrane surface. In conclusion, this study successfully develops nanocellulose-based membranes for efficient AZO dye removal, contributing to sustainable water treatment technologies and environmental preservation efforts.

Development of TiO2-CaCO3 Based Composites as an Affordable Building Material for the Photocatalytic Abatement of Hazardous NOx from the Environment.

This study explores the depollution activity of a photocatalytic cementitious composite comprising various compositions of n-TiO2 and CaCO3. The photocatalytic activity of the CaCO3-TiO2 composite material is assessed for the aqueous photodegradation efficiency of MB dye solution and NOx under UV light exposure. The catalyst CaCO3-TiO2 exhibits the importance of an optimal balance between CaCO3 and n-TiO2 for the highest NOx removal of 60% and MB dye removal of 74.6%. The observed trends in the photodegradation of NOx removal efficiencies suggest a complex interplay between CaCO3 and TiO2 content in the CaCO3-n-TiO2 composite catalysts. This pollutant removal efficiency is attributed to the synergistic effect between CaCO3 and n-TiO2, where a higher percentage of n-TiO2 appeared to enhance the photocatalytic activity. It is recommended that CaCO3-TiO2 photocatalysts are effectiveness in water and air purification, as well as for being cost-effective construction materials.

Development of iron oxide nanoparticles using egg peel (brown) extract as a useful tool for removing the MB dye

The development of iron oxide nanoparticles (IO-NPs) (Fe3O4 and γ-Fe2O3) synthesized from ferric chloride (FeCl3) with egg peel extract by the hydrothermal method at different temperatures for the removal of methylene blue dye (MB) (Fe3O4 and γ-Fe2O3) NPs were diagnosed using (XRD) analysis, (FE-SEM) analysis, (TEM) images, (VSM) instrument, (UV–Vis) spectra, and (FTIR) spectroscopy. XRD measurements explained a crystallinity size of about 15 nm and a face center cubic structure (FCC) for Fe3O4 synthesized from egg peel (brown) extract at 200 °C, while for γ-Fe2O3 NPs prepared using egg peel (brown) extract at 400 °C, the crystal peak structure referred to a cubic structure (maghemite). The average grain size of Fe3O4 NPs was 18.61 to 27.91 nm; however, it was 31.25 to 125.5 nm for γ-Fe2O3 NPs, according to FESEM. Average grain size and the morphology of Fe3O4 and γ-Fe2O3 NPs were (14.7 nm to 26.1 nm) and the spherical structure was determined by the TEM images. The saturation magnetization (Ms) values were 8.12 emu/g and 9.39 emu/g, respectively, for Fe3O4 and γ-Fe2O3 NPs measured with the VSM device. The UV–visible data indicated a blue shift to the band energy gap of 4.1 eV for Fe3O4 NPs but 2.5 eV for γ-Fe2O3 NPs. The absorption band for Fe3O4 NPs is robust at 681 cm−1 at 200 °C, whereas it gets weaker at 650 cm−1 for γ-Fe2O3 NPs at 400 °C, according to FTIR. A photocatalytic activity value explained (Fe3O4 and γ-Fe2O3) NPs affected the MB dye's removal. A results referred to the synthesized Fe3O4 (magnétite) synthesized at 200 °C showed a higher removal efficiency (95 %) at 40 min than the γ-Fe2O3 (maghemite) at 400 °C, for which, after 65 min, the removal efficacy was 90 %.

Novel evolution of gamma irradiated PVP/Cu–Ag nanocomposite for dye polluted water treatment

A novel polyvinylpyrrolidone/copper–silver (PVP/Cu–Ag) nanocomposite was synthesized via aqueous solution reduction and gamma radiation techniques for the treatment of methylene blue dye (MB) polluted water as a common organic dye pollutant in wastewater which is harmful to human health and aquatic life. Different analyses were used for the characterization of the synthesized Cu–Ag nanoparticles (NPs) and PVP/Cu–Ag nanocomposites such as XRD, TEM, DLS, FTIR, EDX, and TGA The XRD results indicated the typical peaks of CuNPs and AgNPs and the formation of pure crystalline nanoparticles in addition to their corresponding peaks were noticed in the PVP/Cu–Ag nanocomposite. Results of FTIR for the PVP/Cu–Ag nanocomposite confirmed the successful interaction between Cu–Ag NPs and PVP chains. The SEM of the PVP/Cu–Ag nanocomposite appeared rough and dense porous surface with white spots of Cu–Ag nanoparticles that dispersed homogeneously all over the surface of the PVP matrix. The effect of the dose of gamma radiation on the gelation and swelling of PVP hydrogel and PVP/Cu–Ag nanocomposite was studied. Using 15 kGy, the gel content of 89% and 97.1% for PVP and PVP/Cu–Ag, respectively. The swelling degree of PVP/Cu–Ag nanocomposite shows pH dependence and the maximum swelling was at pH 6. The point of zero charge (pHpzc) of PVP/Cu–Ag nanocomposite was 5.8. The factors affecting the removal of MB dye were evaluated as the effect of reaction time, dosage, temperature, pH, and dye concentration. The PVP/Cu–Ag nanocomposite shows fast adsorption of MB dye with a removal percentage of 95% after 50 min, at pH 8, 200 mg/L dye concentration, and 0.1 g nanocomposite dosage. Based on the kinetic, isotherm, and thermodynamic studies, it was found that the adsorption of MB dye onto PVP/Cu–Ag nanocomposite fitted to the Pseudo-second-order kinetic model and the Langmuir isotherm model and the reaction was an endothermic, spontaneous, and chemisorption. The fast removal of the dye using the PVP/Cu–Ag nanocomposite confirms its possible use in wastewater treatment applications as an effective adsorbent for dye treatment.

Efficient removal of methylene blue dye from aqueous solution using a new biosorbent derived from Ensete ventricosum (Enset)

In this study, kocho was prepared from pseudostem and corm of Ensete ventricosum (enset).The behaviors of kocho were examined by using FESEM, TGA, XRD and FTIR spectroscopy. The biosorption potential of kocho, a possible low-cost new biosorbent for the efficient removal of MB dye from wastewater was investigated. Biosorption experiments were carried out in batch mode to study the effects of biosorbent dosages (0.025-0.2 g), pH (2–10), initial concentrations of MB (10 to 100 mg/L) and contact time (10 to 120 min).The highest removal efficiency of methylene blue dye (94.2%) was recorded at optimum experimental conditions. Following the removal study, it was determined that the pseudo-second order kinetics (R2 = 0.997) and Langmuir isothermal (R 2= 0.996) models may well describe the MB dye biosorption process. Furthermore, this newly developed biosorbent was fairly recyclable up to five cycles without significant loss of re-adsorption efficiency (around 9.6% loss) between 1st and 5th cycle. Thus, the findings of this study revealed that a new kocho biosorbent derived from Ensete ventricosum can be used as a promising low-cost, environmentally friendly and efficient biosorbent for the rapid removal of MB from aqueous solutions.
 KEY WORDS: Kocho, Ensete ventricosum, Biosorption, Methylene blue, Kinetics, Isothermal
 Bull. Chem. Soc. Ethiop. 2024, 38(1), 69-84. DOI: https://dx.doi.org/10.4314/bcse.v38i1.6