Methylene Blue Adsorption Research Articles

Methylene Blue Removal Using Activated Carbon from Olive Pits: Response Surface Approach and Artificial Neural Network

This study evaluated the efficiency of methylene blue (MB) removal by using activated carbon produced from olive pits. The activated carbon (OPAC) was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET). The adsorption process was optimized in two stages using factorial design. Based on the existing literature, the first stage selected the most influential variables (reaction time, dosage, pH, and dye concentration). Response surface methodology (RSM) and artificial neural network (ANN) approaches have been combined to optimize and model the adsorption of MB. To assess the optimal conditions for MB adsorption, RSM was initially applied using four controllable operating parameters. Throughout the optimization process, various independent variables were employed, including initial dye concentrations ranging from 25 to 125 mg/L, adsorbent dosages ranging from 0.1 to 0.9 g/L, pH values spanning from 1 to 9, and contact times ranging from 15 to 75 min. Moreover, the R2 value (R2 = 0.9804) indicates that regression can effectively forecast the response of the adsorption process within the examined range. Thermodynamic studies were performed for three different temperatures between 293 and 303 K. Isothermal analysis parameters and negative Gibbs free energy indicate that the process is spontaneous and favorable. The data best fit the Langmuir model. This research showcases the effectiveness of optimizing and predicting the color removal process through the combined RSM-ANN approach. It highlights the effectiveness of adsorption using OPAC as a viable primary treatment method for the removal of color from wastewater-containing dyes.

Interfacial Adsorption Interactions of Dyes and Chitosan/Activated Carbon@Curcumin Derivatives in Single-Component and Binary Solutions.

The remediation of wastewaters contaminated with dyes (discharged mainly from industry) is very important for preserving environmental quality and human health. In this study, a new composite chitosan (CS)-based adsorbent combined with activated carbon (AC) and curcumin (Cur) (abbreviated hereafter as CS/AC@Cur) in three different ratios (12.5%, 25%, and 50%) was synthesized for the removal of anionic [reactive black 5 (RB5)] and cationic [methylene blue (MB)] dyes in single-component or binary systems. The synthesized materials were completely characterized through Fourier transform infrared spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis, and X-ray diffraction. Specifically, a decrease in the surface area of CS/AC@ was observed with the addition of curcumin, from 163 to 18 m2/g, for all CS/AC@Cur derivatives. In terms of the adsorption results, the optimal derivative for the removal of both RB5 and MB was found to be CS/AC@Cur50%, providing 93% removal at pH 2.0 ± 0.1 for RB5 and 54% removal at the optimum pH of 9.0 ± 0.1 due to electrostatic attractions. The Elovich and pseudo-second-order kinetic model, with a correlation coefficient R2 of >0.98, better tailored the results, indicating that adsorption was controlled by chemisorption. In addition, the Sips (Langmuir-Freundlich) isotherm model fitted better to the results, with calculated capacities of 338 and 307 mg/g for RB5 and MB, respectively. The thermodynamic analysis showed a spontaneous and endothermic procedure, with chemisorption as the main mechanism. Reuse experiments showed that the removal efficiency was retained at high levels, while stability studies revealed that the adsorbent retains its structural integrity, even at extreme pH values. Finally, the adsorption of RB5 and MB in a mixed solution was investigated, providing a competitive effect between the anionic and cationic dyes.

Synergizing Monte Carlo simulations and experimental insights for efficient cationic dye removal using natural fluorapatite.

Natural fluorapatite (FAP) has been investigated as an adsorbent for the removal of dyes such as methylene blue (MB) and crystal violet (CV) from aqueous solutions. Effective dye removal is crucial for water treatment, particularly for industrial wastewater containing toxic dyes. FAP, a naturally abundant material, was characterized using XRD, FTIR, and SEM analysis. The maximum adsorption efficiency achieved was 97% (23 mg/g) for CV and 95% (13 mg/g) for MB under optimal conditions within an equilibrium time of 50 min. The adsorption capacity increased with the ionic strength of the dye solution, reaching 35 mg/g for CV and 28 mg/g for MB. The kinetic study showed that the adsorption of CV and MB is well described by the pseudo-second-order kinetic model (R2 = 0.999) and fits the Freundlich model significantly, with an R2 = 0.99 for both studied molecules. The thermodynamic analysis (ΔH° = 22.647 and 14.907 kJ.mol-1, ΔS° = 88.627 and 47.330 J.mol-1.K-1 for CV and MB, respectively) revealed that the adsorption process is spontaneous and endothermic, with significant randomness at the adsorbent-adsorbate interface. However, desorption and regeneration tests showed that the efficiency of FAP decreases upon reuse. Despite this, the abundance of natural FAP balances its drawbacks. MD simulations confirmed that adsorption is exothermic and spontaneous, especially in basic conditions, where Van der Waals interactions dominate. These findings suggest that natural FAP has significant potential for dye removal in wastewater treatment applications. The effects of various parameters, including dye concentration, temperature, adsorbent mass, and pH, on the adsorption capacity of FAP were studied. Experimental conditions included an initial dye concentration of 20 mg/L, adsorbent mass of 1 g/L, pH of 12, and temperature of 298 K. The Freundlich model was used to describe the adsorption process, while MD simulations provided insights into the adsorption mechanism.

Fabrication of Polydopamine/hemin/TiO2 Composites with Enhanced Visible Light Absorption for Efficient Photocatalytic Degradation of Methylene Blue

With the rapid progression of industrialization, water pollution has emerged as an increasingly critical issue, especially due to the release of organic dyes such as methylene blue (MB), which poses serious threats to both the environment and human health. Developing efficient photocatalysts to effectively degrade these pollutants is therefore of paramount importance. In this work, titanium dioxide (TiO2) was modified with the photosensitizer hemin and the hydroxyl-rich polymer polydopamine (PDA) to enhance its photocatalytic degradation performance. Hemin and PDA function as photosensitizers, extending the light absorption of TiO2 into the visible spectrum, reducing its bandgap energy, and effectively promoting separation of photogenerated electron–hole pairs through conjugated structures. Additionally, the strong adhesion of PDA enabled the rapid transfer and effective utilization of photogenerated electrons, while its abundant phenolic hydroxyls increased MB adsorption on the photocatalyst’s surface. Experimental results demonstrated a significant enhancement in photocatalytic activity, with the 1%PDA/3%hemin/TiO2 composite achieving degradation rates of 91.79% under UV light and 71.53% under visible light within 120 min, representing 2.22- and 2.05-fold increases compared to unmodified TiO2, respectively. This research presents an effective modification approach and provides important guidance for designing high-performance TiO2-based photocatalysts aimed at environmental remediation.

Removal of dyes from aqueous solution using a magnetic graphene oxide nanocomposite: kinetic, isothermal, and thermodynamic characterization

The efficacy of utilizing graphene-magnetite nanocomposite for methylene blue and crystal violet adsorption treatment from aqueous samples was investigated in this study. The nanocomposite properties were evaluated by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and vibrating quantum magnetometry. Some adsorption parameters such as adsorption capacity, contact time, stirring rate, temperature, and pH of the aqueous solution were explored in the research too. Moreover, it was found that adsorption followed a pseudo-second-order kinetic model with an R2 value of 0.999 resulting in a maximum adsorption capacity of 240 mg/g for methylene blue and 203 mg/g for crystal violet respectively. Besides, different well-known isotherm models fit the equilibrium data well. Assessments of thermodynamic parameters showed that the removal of both dyes by GO-Fe3O4 nanocomposite is spontaneous. Also, the reuse ability of GO-Fe3O4 nanocomposite was studied and the result was shown to be recycled suitably and possessed adsorptive properties so that it can be developed as an inexpensive and alternative adsorbent for dye wastewater treatment.

Initial physiochemical characterization of Djulis (Chenopodium formosanum) spent mushroom substrate biochar and its application for methylene blue dye adsorption, isotherm, kinetics, and parameters

Initial physiochemical characterization of Djulis (Chenopodium formosanum) spent mushroom substrate biochar and its application for methylene blue dye adsorption, isotherm, kinetics, and parameters

An exploration of RSM, ANN, and ANFIS models for methylene blue dye adsorption using Oryza sativa straw biomass: a comparative approach

This study focused on simulating the adsorption-based separation of Methylene Blue (MB) dye utilising Oryza sativa straw biomass (OSSB). Three distinct modelling approaches were employed: artificial neural networks (ANN), adaptive neuro-fuzzy inference systems (ANFIS), and response surface methodology (RSM). To evaluate the adsorbent’s potential, assessments were conducted using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The evaluation of RSM, ANN, and ANFIS included the quantification of R2, mean squared error (MSE), root mean square error (RMSE), and mean absolute error (MAE) metrics. The regression coefficients from the process modelling demonstrated that RSM (R2 = 0.9216), ANN (R2 = 0.8864), and ANFIS (R2 = 0.9589) all accurately predicted MB adsorptive removal. However, comparative statistical analysis revealed that the ANFIS model exhibited superior accuracy in data-based predictions compared to ANN and RSM models. The ideal pH for MB adsorption utilizing OSSB was established as 7. Additionally, favourable outcomes were obtained with 60-minute contact durations, 20 mg adsorbent quantities, and temperatures of 30 °C. The pseudo 2nd -order kinetic model for MB adsorption by OSSB was confirmed. The equilibrium data exhibited a superior fit with the Langmuir isotherm model in comparison to the Freundlich model. The thermodynamic adsorption parameters, including (∆G = -9.1489 kJ/mol), enthalpy change (∆H = -1457.2 kJ/mol), and entropy change (∆S = -19.03 J mol−1 K−1) indicated that the adsorption of MB onto the OSSB surface is exothermic and spontaneous under the experimental conditions. This research effectively showcased the potential of RSM, ANN, and ANFIS in simulating dye removal using OSSB. The generated parameter data proved valuable for the design and control of the adsorption process.

Rapid adsorption of industrial cationic dye pollutant using base-activated rice straw biochar: performance, isotherm, kinetic and thermodynamic evaluation

This work intends to effectively remove methylene blue (MB) dye from wastewater using an agricultural waste-derived sorbent made from pyrolyzing rice straw to generate biochar. This is done while keeping the sustainability idea in mind and tackling the crises arising from environmental contamination with dyes. The physicochemical scrutinization of the non-activated and the base-activated biochar materials showed that the materials have promising textural properties and surface functionalization, leading to high and fast capability to retrieve MB from aqueous solutions in alkaline conditions. The adsorption equilibrium for all the biochar was reached within a time span of 15 min, but 90 percent of the dye removed at equilibrium was already eliminated in less than 5 min. The behaviour of the equilibrium adsorption for the biochar materials was thoroughly assessed using Langmuir and Freundlich adsorption isotherms. Interestingly, the adsorption process for the base-activated biochar follows both Langmuir and Freundlich isotherms at higher pH. The base-activated biochar exhibited a maximum adsorption capacity of 129.87 mg/g at alkaline pH. The adsorption data analysis with various kinetic models revealed that the adsorption process follows a pseudo-second-order kinetics for all the biochar materials. The Gibbs free energy and activation energy studies clearly revealed the adsorption of MB on biochar to be spontaneous and physiosorption in nature. The adsorption mechanism of the fast and efficient removal of MB by the base-activated biochar involves electrostatic interactions, hydrogen bonding, n-π and π-π interactions. Overall, the base-activated biochar with higher and faster adsorption capacity in alkaline conditions is a promising low-cost bioadsorbent with a simple production process for the removal of cationic dyes from aqueous environments and practical dyeing wastewater purification.

Co-Hydrothermal Carbonization of Sawdust and Sewage Sludge: Assessing the Potential of the Hydrochar as an Adsorbent and the Ecotoxicity of the Process Water

Hydrothermal carbonization (HTC) is a promising thermochemical process to convert residues into hydrochar. While conventional HTC utilizes one type of residue as raw material only, Co-HTC generally combines two. By mixing dry and wet wastes, Co-HTC can advantageously avoid water addition. Therefore, this work investigated the potential of hydrochar derived from the Co-HTC of sawdust and non-dewatered sewage sludge as a dye (methylene blue) adsorbent and evaluated the toxicity of the resulting Co-HTC process water (PW) on Daphnia magna. Three hydrochars were produced by Co-HTC at 180, 215, and 250 °C and named H-180, H-215, and H-250, respectively. For methylene blue adsorption, H-180 and H-215 had a better performance than H-250. Both H-180 and H-215 presented a maximum adsorption capacity of approximately 70 mg·g−1, which was superior compared with the adsorption of methylene blue by other hydrochars in the literature. Moreover, the removal percentage obtained with H-180 remained satisfactory even after five cycles. Regarding the toxicological assays of the PWs, raising the Co-HTC temperature increased the variety of substances in the PW composition, resulting in higher toxicity to D. magna. The EC50 values of PW-180, PW-215, and PW-250 were 1.13%, 0.97%, and 0.51%, respectively. This highlights the importance of searching for the treatment and valorization of the PW. Instead of viewing this by-product as an effluent to be treated and disposed of, it is imperative to assess the potential of PWs for obtaining other higher added-value products.

Phosphoric acid based geopolymer foam-activated carbon composite for methylene blue adsorption: isotherm, kinetics, thermodynamics, and machine learning studies.

In this study, a binary composite adsorbent based on activated carbon and phosphoric acid geopolymer foam (ACP) was prepared by combining phosphoric acid geopolymer (PAGP) with activated carbon (AC) and applied for the removal of methylene blue (MB). Activated carbon was thoroughly mixed with a mixture of fly ash and metakaolin in varying ratios, followed by phosphoric acid activation and thermal curing. The ACP adsorbent was characterized using scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectrophotometer, X-ray diffractometer (XRD), surface area analyser (SAP), and thermogravimetric analyser (TGA). Batch analysis was performed to examine the effects of various adsorption parameters including pH (2, 4, 6, 7, 8, and 10), adsorbent dosage (0.06-0.2 g), MB concentration (50-250 mg L-1), contact duration (up to 240 minutes), and temperature (25-55 °C). The ACP with 70% PAGP and 30% AC was found to be the most suitable adsorbent as it maintained its structure and exhibited better MB adsorption. The ACP had a surface area of 47.36 m2 g-1 and a pore size of 5.6 nm and was found to be amorphous in nature. The adsorption equilibrium reached in 240 minutes at pH 7, indicating an efficient adsorption process. The adsorption increased with the initial dye concentration and decreased with the increase in temperature. The ideal parameters for adsorption of MB using ACP include 0.2 g of adsorbent, 25 °C, pH 10, and 240 minutes. The adsorption data fitted well with the Langmuir isotherm, pseudo-second-order (PSO) kinetics model, and three-step intraparticle diffusion (IPD) model. The adsorption capacity calculated using the Langmuir isotherm was 204.8 mg g-1 with an R 2 = 0.989. Thermodynamics parameters showed that the adsorption process was exothermic, energetically favourable, and associated with a decrease in entropy. According to the FTIR findings, pH effect, Langmuir isotherm, PSO kinetics, IPD model, and thermodynamics factors, chemisorption is identified as the predominant process. Different machine learning models, i.e., gaussian process regression (GPR), support vector regression (SVR and SVR-rbf), random forest regression (RFR), decision tree regression (DTR) and artificial neural network (ANN), were trained and tested using adsorption capacity and % removal data. The ANN model (random search) demonstrated better performance compared to other models, achieving an R 2 value of 0.873 for adsorption capacity and 0.799 for % removal on test data.

Use of Modified Activated Carbon in Groundwater Remediation for Human Consumption

This study aimed to produce activated carbon from desilicated rice husks using various carbonization and activation methods, including a tube furnace, muffle furnace, and artisanal pyrolysis. The resulting activated carbons were characterized for their adsorptive capacity through the determination of iodine number and methylene blue adsorption; these are key indicators of specific surface area and adsorbent quality. Advanced characterization techniques were employed, such as scanning electron microscopy (SEM), which revealed a highly porous and irregular surface structure, and energy dispersive X-ray spectroscopy (EDS), confirming the effective removal of impurities and optimization of the elemental composition. Atomic force microscopy (AFM) demonstrated favorable surface roughness for adsorption processes. Among the samples, CaDH162-CADH53 exhibited the highest performance, with an iodine number of 1094.8 mg/g and a yield of 93.5%, signifying a high adsorption capacity. The activation treatments with phosphoric acid and calcium carbonate significantly improved the porous structure, further enhancing the material’s adsorptive properties. In conclusion, the activated carbons produced in this study demonstrated optimal physicochemical properties for water purification and contaminant treatment applications. These findings highlight the potential of using agricultural waste, such as rice husk, as a sustainable and scalable alternative for industrial-scale activated carbon production.

Synthesis of novel magnetic carboxyl-functionalized crosslinked copolymer microspheres for methylene blue removal from water

Magnetic carboxyl-functionalized crosslinked copolymer microspheres of α-methyl styrene and maleic anhydride (MCPMs) with a uniform particle size were synthesized based on self-stabilized precipitation polymerization. Magnetic crosslinked copolymer microspheres (MPMs) were prepared by in situ polymerization using oleic acid-modified Fe3O4 as the magnetic source, α-methyl styrene and maleic anhydride as monomers and divinylbenzene as the crosslinking agent, and MCPMs were then obtained by hydrolyzing the anhydride groups of MPMs into carboxyl groups. The as-prepared MCPMs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, vibrating sample magnetometry and the Brunauer–Emmett–Teller method. The adsorption behavior, adsorption kinetics and adsorption isotherms of MCPMs for methylene blue (MB) removal from water were systematically investigated. It was found that MCPMs manifested good MB removal ability from water with a maximum MB adsorption capacity of 315 mg/g. The kinetic and isothermal data of MCPMs for MB removal followed the pseudo-second-order model and the Langmuir isothermal model, respectively. In addition, MB-loaded MCPMs could be separated easily by magnets, and the MB removal rate of MCPMs still reached more than 90.0% after five cycles. These results indicate that MCPMs have great potential in cationic dye wastewater treatments.

A Comparative Kinetic and Thermodynamic Adsorption Study of Methylene Blue and Its Analogue Dye on Filter Paper.

A comparative adsorption study was carried out for methylene blue (MB) and its 3,7-bis(N,N-(2-hydroxyethyl)amino)-phenothiazinium dye analog (MBI). Batch experiments employed aqueous solutions and commercial filter paper. Out of seven kinetic models tested by means of four quality statistical indicators, the pseudo-second-order, the double-exponential, and the bi-linear Weber-Morris equations were best fits. For both dyes, the process was described as a succession of two diffusion-controlled steps. The Freundlich isotherm was chosen from 11 models describing a variety of mechanism assumptions. Physisorption was considered responsible for the dye removal from liquid. Adsorption of MB is thermodynamically favored, whereas that of MBI is sterically hindered. Both processes are exothermic and exhibit reduced randomness at the S-L interface. The paper was found suitable for retaining MB but served rather filtration/purification purposes for MBI.

Nitrogen-doped reduced graphene oxide for high efficient adsorption of methylene blue.

A highly efficient and widely applicable adsorbent for the removal of methylene blue (MB) was created using nitrogen-doped and reduced graphene oxide (NRGO). The effects of NRGO mass, pH, contact time, and the initial MB concentration on the adsorption properties of MB onto NRGO were investigated. The results showed that the adsorption behavior remained stable within the pH range of 2.0-10.0, and the adsorption process gradually reached equilibrium after 24h. Additionally, the adsorption kinetics and adsorption isotherms were discussed to propose a theoretical adsorption mechanism. Meanwhile, some characterizations including Scanning Electron Microscopy, Energy Disperse X-ray Spectroscopy, X-ray Photoelectron Spectroscopy, X-ray Powder Diffraction, Fourier Transform Infrared Spectroscopy, etc. were used to explore potential adsorption mechanism, which indicated the physisorption caused by π-π bonds was the main adsorption mechanism. NRGO exhibits efficient MB absorption and holds significant potential application for the wastewater treatment.

Preparation and Adsorption Properties of Corn Straw Amphoteric Adsorbent for Cationic and Anionic Dyes

AbstractA highly efficient and environmentally friendly corn straw amphoteric adsorbent (CSAA) was produced using pretreatment, etherification, and graft copolymerization of corn straw (CS) for the purpose of removing methylene blue (MB) and acid red 1 (AR1). The CSAA was subjected to characterize utilizing SEM, FTIR, XRD, Zeta surface potential, and TG. The impacts of pH value, adsorbent dosage, dye concentration, and salt concentration on the adsorption of MB and AR1 by CSAA were examined. The concurrent removal of cationic and anionic dyes under different pH levels has been successfully shown, exhibiting potential utility in dye wastewater. The pseudo‐second‐order kinetic equation indicated a superior match with the empirical data, suggesting that the principal adsorption mechanism may be attributable to ionic attraction. The equilibrium adsorption isotherm study of the CSAA demonstrated a stronger conformance with the Langmuir isotherm model and the maximum adsorption capacity reached 356.2 and 408.2 mg·g−1 for MB and AR1, respectively. Furthermore, the thermodynamic parameters revealed that adsorption reaction using CSAA was spontaneous and exothermic.

Controlled synthesis of ternary acrylamide/sodium acrylate/polyethyleneglycol hybrids by integrating different clays and fillers: a comprehensive evaluation of structural features.

A series of anionic poly(acrylamide-co-sodium acrylate)/poly(ethylene glycol), PAN/PEG, hybrids were conveniently synthesized via free radical aqueous polymerization by integrating bentonite, kaolin, mica, graphene and silica, following a simple and eco-friendly crosslinking methodology. A comparative perspective was presented on how integrated nanofillers affect the physicochemical properties of hybrid gels depending on the differences in their structures. Among the five types of nanofillers, bentonite-integrated hybrid gel had the highest water absorbency, while graphene-integrated gel had the lowest. The elastic moduli of hybrid gels with the same content of inorganic component followed the order graphene > silica > mica > kaolin > bentonite. Adding 1.50% (w/v) bentonite to the PAN/PEG matrix increased the elastic modulus by 1.4 times compared to the as-prepared state, while adding the same amount of graphene created a 4.1-fold increase. By decreasing the synthesis temperature of hybrids to cryoconditions, -18 °C, an increase in the modulus of all gels was observed, while the modulus of graphene-doped gels increased from 25.9 kPa to 39.1 kPa. pH-dependent swelling demonstrated that hybrid gels can dynamically bind or release protons in response to changes in surrounding pH and thus abruptly change their overall dimensions. On-off switching behavior as reversible pulsatile swelling in pH 11.2 and deswelling in pH 2.1 showed that hybrid gels exhibit reversible pH-responsiveness following Fickian diffusion of water into the hybrid matrix. The change in pH of the swelling medium caused a 4.5-fold increase in swelling ratio for the silica-doped hybrid gels. The studies in which anionic hybrids were tested to explore adsorption potential for cationic dye methylene blue (MB) showed that adsorbent properties could be tuned to the desired extent by incorporating different fillers. In terms of efficiency among the selected fillers, the maximum efficiency for MB was obtained as 99.2% and 88.60% for hybrids containing graphene and silica, respectively. The adsorption of MB on hybrids was fit to the three-parameter Sips model rather than the two-parameter models. The results introduced a new perspective on the design of ternary hybrid gels that could effectively address both the mechanical and responsive properties of soft materials, providing a platform for subsequent cationic dye adsorption.

Mechanistic impact of sodium nitrate on the characteristics of MWCNTS oxidation and potential application on methylene blue adsorption from wastewater

Mechanistic impact of sodium nitrate on the characteristics of MWCNTS oxidation and potential application on methylene blue adsorption from wastewater

Preparation of nitrogen-doped lignin porous carbon using low dosage KHCO3 for efficient methylene blue adsorption: Activation mechanism and adsorption performance

The previous requirement for activation of porous carbon adsorbents commonly exceeded several times the mass of the carbon precursor. Therefore, it was crucial to develop cost-effective and efficient carbon adsorbent materials for long-term environmental remediation. In this study, biorefinery lignin was utilized to fabricate porous carbon with an ultrahigh specific surface area (3423 m2 g−1) and pore volume (1.52 cm3 g−1) by employing melamine as the nitrogen source and a low dosage of KHCO3 as the activator. Multiple activations during the carbonization process contributed to the exceptional characteristics of the porous carbon, including well-developed pore structure, high specific surface area, and reasonable nitrogen doping. The porous carbon demonstrated remarkable adsorption capabilities with a maximum methylene blue (MB) adsorption capacity of 1457 mg g−1. Structural characterization conducted before and after adsorption revealed that electrostatic interactions, pore filling, hydrogen bonding, and π-π stacking were among the main mechanisms employed by lignin porous carbon for effective MB adsorption. The proposed method is a simple, green, highly efficient, and environmentally friendly approach that can be applied to treat lignin from various industrial sources. It provides valuable insights into the development of advanced carbon materials suitable for adsorption and capacitor applications.

Hollow spherical g-C3N4 rich in cyano groups for efficient adsorption and photodegradation of methylene blue

Hollow spherical g-C3N4 rich in cyano groups for efficient adsorption and photodegradation of methylene blue

Synthesis of waterborne polyurethane-carboxymethyl chitosan cross-linked biodegradable bio-based porous materials for the adsorption of methylene blue

Synthesis of waterborne polyurethane-carboxymethyl chitosan cross-linked biodegradable bio-based porous materials for the adsorption of methylene blue