Adsorption Of Methylene Blue Dye Research Articles

Strong, tough, conductive and transparent nanocellulose hydrogel based on Ca2+-induced cross-linked double-networks and its adsorption of methylene blue dye

A novel multi-performance SHNC/SA/CaCl2 hydrogel with multi-performance was prepared via ultra-low-temperature freeze–thaw cycling and Ca2+ cross-linking for the removal of methylene blue (MB) from industrial wastewater. Various methods were used to characterize the structure and properties of hydrogel, and the internal structure of hydrogel showed a three-dimensional network with hydrogen and ester bonds. The SHNC/SA/CaCl2–15 hydrogel exhibited the highest tensile properties (elongation = 800 %), viscoelasticity (90 kPa), compressive strength (0.45 MPa), tensile strength (0.47 MPa) and ionic conductivity (4.34 S/cm). The maximum adsorption capacity of 2 g SHNC/SA/CaCl2–15 hydrogel was 608.49 mg/g at 40 °C, pH = 8 and adsorption 24 h. The adsorption process of hydrogel toward MB was more consistent with the second-order kinetic model and Langmuir isothermal adsorption model. According to the Langmuir isotherm model, the maximum monolayer adsorption capacity of SHNC/SA/CaCl2–15 hydrogel toward MB can reach 613.88 mg/g. Finally, it was found that the removal rate of SHNC/SA/CaCl2–15 hydrogel for MB was still as high as 90 % after five cycles of the adsorption–desorption test, and it could be reused. The hydrogel can be used as cheap and reusable adsorption material for cationic dyes. Our study provides a new perspective for the development of multifunctional cellulose hydrogel adsorbent materials.

Vibrational, optical, and photocatalytic properties of ZnO/layered carbon nanocomposite synthesized by ball milling

ZnO/layered carbon nanocomposites with varied sizes of ZnO nanoparticles (NPs) were synthesized by mechanical milling of mixture of ZnO NPs and carbon NPs. The NP size of ZnO was controlled with average particle sizes about 19.33, 21.87, 24.21, and 27.89 nm by varying the concentrations of carbon NPs viz 0, 2, 5, and 10 weight percent, respectively, in the mixture. Presence of carbon with ZnO in the form of composite also resulted in the enhanced shift of the band gap of ZnO due to the optical transitions in the impurity states or presence of carbon as compared to the ZnO size change alone. Additionally, the enhancement of absorbance in the visible region with an increase in carbon content was observed. Such an increase in absorbance can enhance the photocatalytic activity of ZnO NPs. Raman bands for ZnO NPs also were found to shift faster in the presence of layered carbon. The quenching of visible photoluminescence emission of ZnO NPs with an increase in concentration of carbon NPs in the composite indicated the phenomenon associated with transfer of electrons from ZnO to layered carbon helping the separation of photo-generated electrons and holes in ZnO and can lead to enhancement of the photocatalytic activity of ZnO NPs. In the photocatalytic studies, it was observed that the degradation of methylene blue (MB) dye was significantly enhanced by the increase of content of layered carbon in the nanocomposite. The sample containing 10% carbon showed the highest adsorption in dark conditions which was up to 60% of the starting strength and this was further enhanced to 88% in the presence of UV radiation. Enhanced adsorption of MB dye and the effective separation of electron–hole pairs due to charge transfer were believed to be the main causes behind such kind of improvement in the photocatalytic effects.

Hybrid rGO/Fe3O4 magnetic nanocomposite for anionic and cationic dye removal application

The adsorption removal of anionic and cationic azo dyes with magnetic nanoparticles was an important technological strategy for the purification of dye-contaminated water. The present work highlights the dye adsorption properties of the solvothermally synthesized hybrid reduced graphene oxide‑iron oxide (rGO/Fe3O4) nanocomposite for the efficient adsorption of methyl orange, congo red, metanil yellow, and methylene blue from the aqueous medium. Morphology, and porous characteristics of the material was analysed with FESEM and BET respectively. The magnetic properties of the material viz. M-H, FC, and ZFC were investigated with SQUID-VSM. The BET analysis confirmed the mesoporous structure of the hybrid rGO/Fe3O4 nanocomposite, with a BET-specific surface area of 27.74 m2/g. Dye adsorption experiments of hybrid rGO/Fe3O4 nanocomposite were conducted to analyse the influence of adsorbent dosage, dye concentrations, and pH variations. FTIR spectroscopy was also used to verify the adsorption of azo dyes onto the surface of the rGO/Fe3O4 nanocomposite. Hybrid rGO/Fe3O4 nanocomposite show complete adsorption of methyl orange, congo red, metanil yellow, and methylene blue dyes with adsorption capacities of 58.76, 100.3, 533, and 50 mg/g, respectively in the water medium. Hybrid rGO/Fe3O4 nanocomposite showed excellent adsorption of metanil yellow dye. The adsorbed azo dyes methyl orange, metanil yellow, methylene blue, and congo red by the rGO/Fe3O4 nanocomposite can be easily desorbs from the material indicating its reusability. The magnetic coercivity of the material at 300K was 47.4 Oe, as a result the adsorbent material can be magnetically separated from the purification system. The adsorption process of methyl orange, congo red, metanil yellow, and methylene blue dyes on the rGO/Fe3O4 nanocomposite best fits to the pseudo-second-order kinetics and the Langmuir isotherm model.

Preparatiοn οf pοrοus hydrοxyapatite-metakaοlin geοpοlymer granules fοr adsοrptiοn applicatiοns using pοlyethylene glycοl as pοrοgen agent and sοdium dοdecyl sulfate as aniοnic surfactant.

This study investigated the elaboration of novel porous absorbent granules by mixing powdered hydroxyapatite, metakaolin, sodium metasilicate, polyethylene glycol, and sodium dodecyl sulfate (SDS), an anionic surfactant. The effect of sodium dodecyl sulfate (SDS) was then studied by introducing it as a powder to the powdered mixture or dissolved into the granulation fluid. Characterization of the granules indicated that the incorporation of SDS dissolved in the granulation fluid into the G-PEG granules improved their specific surface area (97.9 m2/g) and porosity, resulting in a synergistic increase in the adsorption of crystal violet and methylene blue dyes compared to G-PEG granules and hydroxyapatite or metakaolin geopolymer alone. Moreover, the granules exhibited satisfactory compressive strength of 0.81MPa, making them suitable for large-scale adsorption columns. Finally, the regeneratiοn prοcess οf the granules was modeled and optimized by using surface response methodology based on Box-Behnken design. The granules cοuld be regenerated fοr eight cycles under οptimum cοnditiοns οf acetic acid cοncentratiοn οf 0.72 mοl/L, a temperature οf 323K, and a cοntact time οf 173.22min, withοut a significant lοss in the adsοrptiοn capacity οr degradatiοn οf the granules. These results suggest that the pοrοus granules prepared in this study have pοtential tο be used in industrial wastewater treatment.

Unveiling the Nature of lignin's Interaction with Molecules: A Mechanistic Understanding of Adsorption of Methylene Blue Dye.

The valorization of lignin into advanced materials for water and soil remediation is experiencing a surge in demand. However, it is imperative that material research and manufacturing be sustainable to prevent exacerbating environmental issues. Meeting these requirements necessitates a deeper understanding of the role of lignin's functional groups in attracting targeted species. This research delves into the interaction mechanisms between lignin and organic molecules, using the adsorption of the cationic dye Methylene Blue (MB+) as a case study. Herein, we aim to quantitatively estimate the contribution of different interaction types to the overall adsorption process. While carbonyl groups were found to have no significant role in attraction, carboxylic groups (-COOH) exhibited significantly lower adsorption compared with hydroxyl groups (-OH). Through alternately blocking aliphatic and phenolic -OH groups, we determined that 61% of the adsorption occurred through hydrogen bonding and 38% via electrostatic interactions. Performance studies of modified lignin along with spectroscopic methods (XPS, FTIR) confirmed the negligible role of π-π interactions in adsorption. This study offers fundamental insights into the mechanistic aspects of MB adsorption on lignin, laying the groundwork for potential modifications to enhance the performance of lignin-based adsorbents. The findings underscore the importance of hydroxyl groups and provide a roadmap for future studies examining the influence of steric factors and interactions with other organic molecules.

Composite of activated carbon-hydroxyapatite from corn (Zea mays L.) cob and catfish (Pangasius sp.) bones with H3PO4 activation for methylene blue dye adsorption

Methylene blue (MB) is a synthetic dye in wastewater that causes serious environmental problems due to its toxicity, carcinogenicity, and resistance to environmental degradation. To overcome this problem, activated carbon (AC) from corncob waste and natural Hydroxyapatite (HAp) from catfish bone were synthesized to generate a simple, cost-effective, and efficient composite adsorbent for removing MB dye in wastewater. The performance of the AC/HAp composite adsorbent was assessed under varying conditions, including initial dye concentration, contact time, adsorbent dosage, pH, and reusability. The scanning electron microscope (SEM) morphology and BET results showed that the composite had an irregular shape, with a specific surface area of 419.02 m2/g. The results showed that the isotherm model followed the Langmuir model with an adsorption capacity of 109.90 mg/g. Reusing the composite adsorbent after 3 cycles resulted in an insignificant decrease in the MB removal percentage from 73.52 % to 55.32 % at an initial dye concentration of 200 mg/L. Ion exchange, hydrogen bonding, Lewis acid-base interaction, electrostatic interaction, and π–π bond interactions were several adsorption mechanisms. Based on these findings, the composite had the potential to be an MB adsorbent by enhancing agricultural and aquaculture waste value and supporting the implementation of a circular economy and net zero carbon in Indonesia.

Closing the sustainability loop: CuO-infused antibacterial cellulose-dominant matrices for multi-tasking wastewater clean-up and energy storage

In tandem with the water contamination brought about by emerging pollutants (EPs), bacterial contamination assumes a pivotal role in water pollution dynamics. Developing efficient yet uncomplicated adsorbents is crucial to meet these demands, even though it remains a challenging endeavor. Addressing this, a cost-effective and straightforward strategy has been proposed for creating a copper oxide (CuO) infused cellulose-dominant matrix (referred to as CuO@SBF) derived from Saccharum officinarum bagasse, aimed at effective ciprofloxacin (Cpf), and methylene blue (MB) dye adsorption, alongside exhibiting antibacterial activity. The CuO-infused SB filter exhibited remarkable effectiveness in capturing methylene blue (MB), surpassing the originally anticipated performance with an adsorption capacity of 361 mg/g, alongside exhibiting notable antibacterial efficacy, particularly with an 11 mm zone of inhibition against Bacillus cereus. In contrast, filters without CuO showed no inhibition zones, underscoring the significance of CuO for antibacterial properties. Beyond their primary function, the used CuO@SBF underwent high-temperature carbonization under nitrogen atmosphere, at 800 °C for 3 h for point-of-use energy storage devices. Remarkably, this subsequent application produced noteworthy outcomes, with the devices attaining a significant capacitance of 161 F/g at a current density of 0.3 A/g. This multifaceted application not only strengthens the adsorbents' sustainability and economic feasibility, but also opens up promising avenues for repurposing waste materials within the domain of energy storage. Hence, the dual-functional CuO@SB filter, boasting impressive antibacterial prowess, is poised to emerge as a prospective contender for effective emerging pollutant adsorption. Moreover, its multifaceted attributes suggest promising applications across diverse domains in the times ahead.

Nanofiber films reinforced with biomass extracts and their high efficiency in adsorbing dyes

In this study, polyacrylonitrile (PAN) was used as precursor and calcium Lignesulfonate (CLS) as additive to prepare composite films by electrospinning technology for the adsorption of methylene blue (MB) and Congo red (CR) dyes. The composite films were characterized by Brunauer-Emmett-Taylor analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS). The effects of pH value, temperature, concentration and reaction time on adsorption efficiency were investigated. When the content of CLS is 20 wt%, the composite membrane has excellent adsorption performance, and the maximum adsorption capacity of MB and CR are 48 and 23 mg/g.

Tunable dye adsorbing materials from crab and shrimp waste shells for water remediation

Crab and shrimp shells are waste byproducts from shellfish farming and processing. In this study, we demonstrated that it is possible to obtain individual shell components either separately or in combinations. These diverse materials were composed of calcium carbonate and organic molecules inter- and intra-mineral, calcium carbonate and organic molecules intra-mineral, organic molecules such as chitin and proteins, only calcium carbonate, and only chitin. These substrates were tested for the adsorption of Methylene Blue and Eosin dyes. The goal is to demonstrate that the organic dye adsorption capacity can be modified by controlling the degree of deconstruction of the starting material. The best adsorption for the positively charged Methylene Blue was achieved on the chitin-calcium carbonate substrates, while the negatively charged Eosin adsorbed best on the chitin substrate. In conclusion, this research demonstrates that it is possible to obtain different materials by deconstructing the shells from crabs and shrimps at various levels reducing the generation of additional wastes. Moreover, these materials exhibit features that are related to the original material and possess new properties that can be also exploited in other fields like material sciences.

Design and preparation of a novel Mg–Al LDH@EDTA-Melamine nanocomposite for effective adsorptive removal of methylene blue and rhodamine B dyes from water

This paper deals with the preparation of a novel nanocomposite consisted of magnesium-aluminum layered double hydroxide (Mg–Al LDH) and ethylenediaminetetraacetic acid (EDTA) as well as melamine (MA) as an adsorbent. This nanocomposite was utilized to adsorb different dyes such as rhodamine B (RhB) and methylene blue (MB) from water. The prepared adsorbent was characterized using FT-IR, EDS, XRD, TGA, and FE-SEM analyses. The effects of various parameters such as concentration, time, adsorbent dosage, temperature, and pH were tested to investigate their influence on adsorption conditions. Both methylene blue and rhodamine B dyes showed pseudo-second-order adsorption kinetics, and their adsorption followed the Langmuir isotherm. Moreover, the maximum adsorption capacities for methylene blue and rhodamine B were found to be 1111.103 mg/g at 45 °C and 232.558 mg/g at 60 °C, respectively. Additionally, the adsorption processes were found to be spontaneous (ΔG°< 0, for both dyes) and exothermic (ΔH° = −12.42 kJ/mol for methylene blue and ΔH° = −25.84 kJ/mol for rhodamine B) for both dyes. Hydrogen bonding and electrostatic forces are responsible for the interactions occur between the nanocomposite and the functional groups in the dyes. The experimental findings demonstrated a greater adsorption rate of MB than RhB, suggesting the adsorbent's stronger affinity for MB. This preference is likely due to MB's size, specific functional groups, and smaller molecule size, enabling stronger interactions and more efficient access to adsorption sites compared to RhB. Even after recycling 4 times, the dye adsorption percentages of the adsorbent for MB and RhB dyes were 90 % and 87 %, but the desorption percentages of the adsorbate dyes were 85 % and 80 %, respectively. The prepared adsorbent boasts several unique properties, such as the swift and effortless adsorption of MB and RhB dyes, straightforward synthesis, mild adsorption conditions, remarkable efficiency, and the ability to be recycled up to 4 times without a significant decrease in activity.

Optimizing Methylene Blue Dye Adsorption onto Liquid Natural Rubber-Based Hydrogel: Kinetics, Isotherms and Reusability

In recent years, notable advancements have taken place in the textile industry, particularly with the widespread use of synthetic dyes such as methylene blue (MB). However, the environmental impact of these dyes has raised significant concerns. Their potential to influence both chemical and biochemical demand poses risks, leading to potential disruptions in aquatic plant photosynthesis. Additionally, concerns exist regarding the toxicity and potential carcinogenicity of these dyes to humans. This study achieved successful hydrogel synthesis through the efficient utilization of ultrasonic methods, combining liquid natural rubber (LNR), acrylic acid (AAc), and pectin (Pc) to adsorb MB from aqueous solutions. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were employed to analyze the structure. Utilizing Response Surface Methodology (RSM), the study investigated the effects of the AAc:LNR weight ratio and Pc weight on hydrogel preparation for MB removal. This led to the development of a quadratic polynomial model with an ANOVA-derived R2 value of 0.9970. Optimal conditions for hydrogel production were identified as a 3.00 g/g AAc:LNR weight ratio and 0.0325g of Pc, resulting in an impressive 99.07% MB removal effectiveness. The limit of detection (LOD) for methylene blue adsorption was calculated at 0.64 ppm. The kinetics and isotherms of MB removal were described by the pseudo-second-order and Freundlich models, respectively. Furthermore, the investigation into hydrogel reusability demonstrated its capability for up to five utilization cycles. The LNR/AAc/Pc hydrogel exhibits promising potential as an effective, cost-efficient, and environmentally conscious adsorbent for MB removal. This makes it applicable to water treatment scenarios involving cationic dyes.

Kinetic study of adsorption and photocatalytic degradation of methylene blue dye using TiO2 nanoparticles with activated carbon

Activated carbon (AC) exhibits limited adsorption capacity for pollutants. Conversely, titanium dioxide (TiO2) demonstrates excellent photocatalytic performance, making it a popular choice for pollutant removal. This study investigates the removal of methylene blue (MB) dye from wastewater using AC, TiO2@AC-2, and TiO2@AC-10 samples via adsorption and photocatalysis. The Energy Dispersive analysis of x-rays (EDAX) has confirmed the presence of Ti, C and O in the prepared samples without any impurities. All the diffraction peaks in x-ray diffractograms indicated the presence of pure anatase TiO2 (tetragonal phase) with no evidence of any other phase. Fourier transform infrared spectroscopy (FTIR) analysis identified a peak around 545 cm−1 in the TiO2@AC-2 sample, indicative of O-Ti-O stretching vibrations. This peak shifted to 602 cm−1 in the TiO2@AC-10 sample. Raman spectroscopy confirmed the presence of carbon (D and G bands) at 1310–1347 cm−1 and 1582–1597 cm−1. Additionally, characteristic Raman active bands for anatase TiO2 were observed at 154 cm−1 (Eg), 204 cm−1 (Eg), 398 cm−1 (B1g), 508 cm−1 (A1g), and 628 cm−1 (Eg). N2 adsorption–desorption isotherms revealed a mesoporous structure for all samples (AC, TiO2@AC-2, and TiO2@AC-10) with hysteresis loops, indicating pores ranging from 2 nm to 50 nm in diameter. Reflectance spectra of TiO2@AC-2 and TiO2@AC-10 displayed absorption edges at 368 nm and 385 nm, respectively, corresponding to a direct band gap of approximately 3.22 eV. Subsequently, these prepared samples were effectively employed for the removal of methylene blue (MB) dye from wastewater utilizing both adsorption and photocatalysis method. Under dark conditions, 20 mg L−1 doses of TiO2@AC-2 and TiO2@AC-10 resulted in 60% and 36% dye adsorption within 60 min respectively. In the presence of UV radiation, the degradation of dye was observed to be 74% and 95% by TiO2@AC-2 and TiO2@AC-10 respectively. This observation indicates that TiO2 nanoparticles along with AC leads to enhanced photocatalytic activity. The Langmuir–Hinshelwood model reveals lower rate constants for AC compared to the composite samples. This is likely because AC lacks inherent catalytic activity, requiring UV light to trigger adsorption. Conversely, TiO2@AC-10 exhibits the highest rate constants (K1 = 24.25 × 10−3 min−1 and K2 = 82.71 × 10−3 min−1), aligning with its higher TiO2 content confirmed by EDAX analysis. This suggests a significantly faster photocatalytic rate and superior degradation efficiency, even at a low sample concentration (20 mg L−1).

Diffusion and chemical kinetics of methylene blue dye adsorption on silica doped with iron (III) ions

Silica are widely used in catalysis, adsorption, and chromatography. In the last decade, they have been increasingly used in medicine, however, to ensure their biocompatibility, silica need to be modified and the simplest way of such a modification is doping them with iron cations. The article presents a study of the sorption characteristics of silica doped with iron cations. The purpose of the study was to assess the effect of doping silica with iron ions on the kinetics of their adsorption of model sorbate of methylene blue dye. Doped silica were synthesised by the alkoxide sol-gel method at pH=1.5 and pH=5.0 with the introduction of iron cations into the reaction mixture during the hydrolysis of tetraethoxysilane. The iron content in the samples was 1.5, 2.3, and 3.8 at. %. According to the results of X-ray phase analysis, all samples were X-ray amorphous. According to the shape of the isotherms of low-temperature nitrogen adsorption, all samples were classified as microporous. The specific surface area of the samples and the total pore volume decreased slightly with an increase in the iron content in the samples. The adsorption of methylene blue dye was carried out at temperatures of 25, 30, and 35 °C. The kinetic adsorption curves were analysed using the following diffusion kinetics models: Boyd model (external diffusion process) and Weber-Morris model (internal diffusion process). Also, the kinetic data were analysed using kinetic models of pseudo first-order (Lagergren model) and pseudo second-order (Ho and McKay's model). It was established that all samples were characterised by a mixed-diffusion regime of the sorption process. Adsorption kinetics was adequately described by the model of pseudo-second-order.

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.

Production and Characterization of Activated Carbon Derived from Costus Afer Leaves (C. afer) for the Adsorption of Methylene Blue Dye from an Aqueous Solution

In this work, Costus afer leaves (C. after) was utilized as an agricultural waste material for the synthesis of activated carbon (AC) used for the adsorption of methylene blue dye from its aqueous solution. The raw material was prepared, chemically activated using KHCO3 with an impregnation ratio of 1:3, and later carbonized at a temperature of 700℃ in an inert N2 atmosphere for 1hour to produce activated carbon. The proximate analysis of the biomass revealed the percentage of ash content, moisture content, volatile matter, and fixed carbon present in the waste biomass. The raw and activated carbon produced were characterized using various tests such as: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), Fourier Transform Infrared-(FTIR) Spectrometry, X-Ray Fluorescence (XRF), and Brunauer-Emmett-Teller (BET). The results revealed that the SBET of the biomass increased from 400m2/g to 600m2/g after activation. Adsorption studies were carried out in batch mode to determine the influencing factors of adsorption with varying adsorbent dosage, contact time, and pH values. The adsorption experiment revealed high adsorption efficiency at an optimum parameter of dosage (0.2g), contact time (10 min), and pH (8) with a 70.58% removal of methylene blue dye. An increase in dosage, contact time, and pH above the optimum parameter leads to a decrease in percentage removal. The adsorption capacity was achieved using adsorption isotherm models like Langmuir and Freundlich. Adsorption of methylene blue validated the Langmuir model with an R2 of 0.999 and a Qm of 11.83 mg/g. These results show that activated carbon prepared from Costus afer leaves constitutes an effective low-cost material for the adsorption of Methylene dye from wastewater.

Enhanced adsorption capacity of phosphoric acid-modified montmorillonite clay and ground coffee waste-derived carbon-based functional composite beads for the effective removal of methylene blue

Clays, valued for their versatility, serve as economical adsorbents. Recent studies show that physical, thermal, and chemical modifications can enhance their adsorption capacity. In this study, the synthesis of a functional bead comprising phosphoric acid-modified montmorillonite (PMMT) and coffee waste carbon (CWC) and its application for the efficient adsorption of methylene blue (MeB) dye is investigated. A highly flexible and low-cost phyllosilicate, montmorillonite clay, MMT was treated with phosphoric acid to enhance the ionic density, composited with CWC, resulting in improved surface properties thereafter was transformed into easily recoverable bead form through subsequent cross-linking steps. These functional composite beads were characterized using various characterization techniques. As a result, the existing tetrahedral sheets possessed by the MMT having weak bonds between the layers are improved in a way that they can allow molecule exchange for the efficient enhancement of the adsorption capacity of the composite material. Moreover, after the necessary modifications, the adsorbent was found to be mechanically stable, inhibiting secondary pollutions from the use in powder forms while allowing the interlayers favorable for not just cationic but also anionic exchange whilst increasing the specific surface area and pore volume. The surface area was enhanced to 9.93 m2 /g. Following this, maximum adsorption capacity of 489.9 mg/g was attained showing a superior removal efficiency for methylene blue dye (>80%). The adsorption equilibrium was analyzed using Freundlich and Langmuir models. The adsorption mechanism aligns with the Langmuir model which encompasses a monolayer adsorption. All in all, this study is anticipated to play a crucial role in the search for adsorbents with multiple functionalities and good structural stability during and after use.

Blended Nephelium lappaceum and Durio zibethinus wastes for activated carbon production via microwave-ZnCl2 activation: optimization for methylene blue dye removal

Herein, this work targets to employ the blended fruit wastes including rambutan (Nephelium lappaceum) peel and durian (Durio zibethinus) seed as a promising precursor to produce activated carbon (RPDSAC). The generation of RPDSAC was accomplished through a rapid and practical procedure (microwave-ZnCl2 activation). To evaluate the adsorptive capabilities of RPDSAC, its efficacy in eliminating methylene blue (MB), a simulated cationic dye, was measured. The Box–Behnken design (BBD) was utilized to optimize the crucial adsorption parameters, namely A: RPDSAC dose (0.02–01 g/100 mL), B: pH (4–10), and C: time (2–6 min). The BBD design determined that the highest level of MB removal (79.4%) was achieved with the condition dosage of RPDSAC at 0.1 g/100 mL, contact time (6 min), and pH (10). The adsorption isotherm data is consistent with the Freundlich concept, and the pseudo-second-order versions adequately describe the kinetic data. The monolayer adsorption capacity (qmax ) of RPDSAC reached 120.4 mg/g at 25 °C. Various adsorption mechanisms are involved in the adsorption of MB dye onto the surface of RPDSAC, including π–π stacking, H-bonding, pore filling, and electrostatic forces. This study exhibits the potential of the RPDSAC as an adsorbent for removal of toxic cationic dye (MB) from contaminated wastewater.

Tailoring electrospun nanocomposite fibers of polylactic acid for seamless methylene blue dye adsorption applications.

The introduction of biopolymers, which are sustainable and green materials, desegregated nature's water purification proficiency with science and technology, opens a new sustainable methodology in water reclamation. In order to introduce an efficacious adsorbent system for MB dye-toxic pollutant, adsorption, providing robust mechanical properties and facile processability, a facile system was introduced via electrospinning utilizing polylactic acid (PLA) and Ti3C2Tx, viz., PMX. The addition of 3 wt.% Ti3C2Tx led to a 3-fold substantial augmentation in the uptake capacity of the membrane from 197.28 to 307 mg/g when the adsorbate concentration was 100 ppm. The adsorption followed a PSO behavior, proposing that the rate-limiting stage is chemisorption and data best fitted to Freundlich isotherm, indicating heterogeneous adsorption sites and multi-layer adsorption. Further, biodegradability was studied by simulating natural environmental conditions where the nanofibers exhibited 42-64% degradation after 270 days. Based on the result with PLA, it is anticipated that the prepared fibrous system will introduce a new perspective as a potential candidate for MB removal from wastewater, opening new directions toward the research and development in wastewater treatment with electrospun biopolymer fibers using waste PLA.

Exploring the potential of olive pomace derived activated charcoal as an efficient adsorbent for methylene blue dye: a comprehensive investigation of isotherms, kinetics, and thermodynamics

Methylene blue (MB) is a heterocyclic aromatic chemical compound used as a dye in various dyeing processes. The accumulation of such an organic compound poses a significant threat to both the environment and human health. Therefore, numerous biological, physical, and chemical processes have been established to remove MB dye, with adsorption being the most predominant dye-based treatment technology. In this context, the aim of this work was to evaluate the adsorption properties of activated carbon derived from olive pomace against methylene blue. To this end, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR) analyses were carried out to confirm the adsorption of MB on carbon structures. In addition, the effect of contact time, pH, initial dye concentration, adsorbent dose, and temperature on the adsorption efficiency of MB was investigated. On the other hand, kinetic and isothermal models were used to further understand the adsorption mechanism, which showed a good correlation with the pseudo-second-order kinetic model and the Langmuir isotherm. Finally, thermodynamic analysis showed favorable conditions for physisorption, with the process being both endothermic and spontaneous.

Decolourization of Methylene Blue by using Eucalyptus Globulus Leaf Powder as a Adsorbent

In the present study, the feasibility of using low-cost adsorbent Eucalyptus Globulus leaf powder for the cationic dyes adsorption from aqueous solutions have been investigated. Batch adsorption studies are conducted to study conducted to the different parameters are adsorbent dosage of 2-20 g/L, initial dye concentration of 50-250 mg /L, Temperature of 293oK, 303 oK and 313 oK on adsorption of methylene blue dye at equilibrium time of 80 minutes respectively and optimal pH of 5.0. The equilibrium data is analysed with isotherm models are Langmuir and Freundlich and kinetic models are Pseudo-first order, Pseudo-second order model. The adsorption equilibrium and kinetic data fitted well to Freundlich isotherm model for methylene blue dye and Pseudo-second order model for methylene blue dyes. The adsorption is an Endothermic and it is energetically favourable adsorption. The result demonstrates that Eucalyptus Globulus leaf powder could be employed as effective and low-cost adsorbent for the removal of methylene blue and from aqueous solutions.