Methylene Blue Dye Concentration Research Articles

Enhanced methylene blue degradation and miniralization through activated persulfate coupled with magnetic field

In this work, for the first time, the effectiveness of the degradation and mineralization process of methylene blue) MB) was investigated using activated persulfate (PS) with a magnetic field. The effect of various operating parameters, including pH, PS (5–20 mg/L), intensity of the magnetic field (1–4 A), initial concentration of methylene blue dye (25–100 mg/L), and contact time (30–120 min), was evaluated. Process optimization was conducted via the Taguchi model, and the optimal values of these factors were found to be pH = 5, PS = 10 mg/L, MFs = 4 A, reaction time = 30 min, and the initial concentration of methylene blue dye = 50 mg/L. Under optimal conditions, the methylene blue removal efficiency and TOC destruction efficiency reached 91.8% and 88%, respectively. The kinetics of the process followed pseudo-second order (R2 = 0.9723). According to the promising results of the research, the efficiency of dye purification using a magnetic field has increased by about three times compared to the state without this factor. It can be suggested that this system be used as a wastewater treatment process for the textile industry to reduce the toxicity of wastewater and total organic carbon (TOC).

Advanced nano modification of ecofriendly glauconite clay for high efficiency methylene blue dye adsorption

This research focuses on the utilization of nano glauconite clay as an environmentally friendly sorbent for the removal of cationic dyes, particularly Methylene Blue (MB), from polluted water. The glauconite clay was sourced from the El Gidida region of Egypt and subjected to grinding in a laboratory-type ball mill to ensure homogeneity and increase the active sites available for the adsorption process. The resulting ball milled nano clay (BMNC) was characterized using techniques such as X-ray fluorescence (XRF), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The concentration of MB dye was monitored using UV–Vis spectroscopy to assess the adsorption capacity of BMNC under various conditions including pH, time, dose, and temperature. The optimal conditions for the adsorption process were determined to be a pH range of 7–8, a contact time of 60 min, and a dose of 200 ppm, resulting in an adsorption capacity of 128 mg/g. This process demonstrated both low cost and high speed. The adsorption mechanism of MB on the BMNC surface was evaluated through kinetics, adsorption isotherms, and thermodynamics. The experimental data indicated an endothermic, spontaneous, and thermodynamically favourable adsorption process, which was further supported by simulated modelling results using Forcite program. The in-silico data aligned well with the experimental findings. Additionally, the study assessed the interference of salts, metal ions, and other dyes on MB adsorption onto BMNC, showing promising results. These findings strongly support the effectiveness of our sorbent substrate under challenging conditions.

Box-Behnken design optimization of 2D Ti3C2Tx MXene nanosheets as a microwave-absorbing catalyst for methylene blue dye degradation

The 2D MXene Ti3C2Tx was synthesized from the precursor MAX phase Ti3AlC2 by etching the Al layer using hydrofluoric acid. Different Characterization techniques were employed to investigate the properties of the synthesized Ti3C2Tx. The degradation of methylene blue (MB) dye under microwave irradiation in the presence of the prepared 2D MXene was studied. It was found that the synthesized Ti3C2Tx was an excellent microwave catalyst for MB dye degradation, and results obtained were promising. Using this approach, the dye was almost wholly degraded with a degradation efficiency of 99.85 % in only 10 min without adding any oxidant. The degradation was found to follow the pseudo-first-order kinetic model, and the rate constants obtained varied from 0.10 and reached up to 0.67 min−1. The effect of pH, initial MB concentration and catalyst dosage on the MB dye degradation rate has been studied. It was found that carrying out the reaction at pH values ranging from 2 to 10 did not obviously affect its rate. On the other hand, lower initial MB dye concentrations and higher catalyst dosages significantly increased the degradation rate. The high degradation efficiency was found to be maintained for up to five successive catalytic cycles, ensuring the high stability of the synthesized 2D MXene Ti3C2Tx as a catalyst. Optimization of parameters affecting the degradation process was studied using response surface methodology (RSM). According to the Box-Behnken design, the optimal degradation efficiency (99.92 %) could be achieved by adding 21.24 mg of 2D Ti3C2Tx MXene catalyst and using an initial MB dye concentration of 53.06 ppm (mg/L) during a reaction time of 11.93 min.

Synthesis of alginate capped aluminum oxide (Al2O3) nanocomposite for efficient photocatalytic degradation of methylene blue

Abstract In the presence scenario, dye pollution has become a serious issue in present environment protection which need extensive attention of the scientific community. Methylene blue (MB) has been known for its toxic nature and widely used in various industries. In the present work, we reported the green synthesis of alginate capped alumina (Al2O3) nanocomposite (NC). The synthesized Alg@Al2O3 NC have been verified by various sophisticated characterization techniques (XRD, SEM, EDX, UV–vis TEM, FTIR, and XPS). The synthesized Alg@Al2O3 NC have been used as photocatalyst for the degradation of MB dye. Furthermore, photocatalytic activity of the Alg@Al2O3 NC has been studied under ultraviolet (UV) light. The obtained results exhibited excellent photocatalytic properties of the Alg@Al2O3 NC. The effect of photocatalyst doses (0.1–5 g l−1), pH−1 (1–10), MB dye concentration (50–120 ppm), and irradiation time (5–135 min) of UV light were also optimized. The highest efficiency of 99.2% has been observed for MB degradation via Alg@Al2O3 NC. The investigations of kinetics demonstrated that the photocatalytic degradation proceeded along a pseudo-first-order pathway in accordance with the Langmuir–Hinshelwood (L-H) kinetic model. The Alg@Al2O3 NC also exhibited excellent reusability for 4 cycles and suggested that Alg@Al2O3 NC can be used for various cycles. In this study, we proposed the cost-effective green synthetic method for the preparation of Alg@Al2O3 NC and its application as photocatalyst for the removal of MB dye under UV light.

Effectiveness of Porous Durian Shell-based Activated Carbon for Methylene Blue Adsorption

In this study, durian shell-based activated carbon (DAC) was produced via chemical activation method by utilising durian shell and sulphuric acid (H2SO4) as the starting material and activating agent, respectively. The incorporation of H2SO4 in the DAC production process resulted an improvement in the surface properties and adsorption capacity of the produced DAC adsorbent. Field emission scanning electron microscopy analysis further showed that the produced DAC possessed a porous structure which was beneficial for dye adsorption application. Under operating conditions of 500°C and 3 hours carbonisation temperature and time, the Brunauer–Emmett–Teller (BET) surface area, total pore volume and BET average pore diameter were measured to be 242.03 m2/g, 0.028 cm3/g and 2.28 nm, respectively. The adsorption performance of the produced DAC was then investigated using methylene blue (MB) as the model adsorbate. The optimum MB dye removal and adsorption capacity were found to be 92.05% and 0.767 mg/g, respectively, with 0.6 g of DAC dosage, 10 ppm of initial MB dye concentration and 15 min of contact time.

Synthesis of iron loaded jackfruit peel biochar through microwave heating as a stable and active heterogenous Fenton catalyst for dye degradation

Iron-loaded biochar derived from jackfruit peels (Fe-JP) was synthesised by pyrolysis in a microwave furnace and iron was loaded onto the peels prior to pyrolysis, facilitated by sonication. The primary objective of the investigation was to examine the degradation process of methylene blue (MB) dye and Acid Red 1 (AR1) dye by the using Fe-JP biochar as a heterogeneous Fenton catalyst. The investigation encompassed an examination of the impact of different operating parameters, such as pH, catalyst dosage, and H2O2 concentration. The synthesised Fenton catalyst underwent characterization using Field Emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques, Fourier transform infrared (FTIR) spectra analysis, Raman spectroscopy, Brunauer-Emmet-Teller (BET) analysis. At a pH of 3, using an initial MB dye concentration of 20 mg/L and initial AR1 dye concentration of 50 mg/L, an 8 mM H2O2 concentration, and a catalyst dose of 2 g/L, the maximum dye removal efficiency reached 96.5 % and 98 % respectively, while the total organic carbon (TOC) removal efficiency reached 68.5 % and 75 % respectively. The observed reaction time under the given experimental conditions was 120 min. The thermal stability of the biochar catalyst was found to be excellent based on the Thermogravimetric analysis (TGA) and Differential Scanning Calorimeter (DSC) studies. The catalysts that were developed demonstrated remarkable durability and negligible leaching of iron, hence enabling their repeated usage in subsequent cycles. The findings of the investigation suggest that the primary mechanism responsible for the degradation of the dye was the surface-based heterogeneous Fenton activity. Additionally, the effect of adsorption on the elimination of colour under varying pH conditions was examined, which had a very low influence in dye degradation (<30 %). The conducted scavenging investigations in the research have indicated the major involvement of hydroxyl radicals (OH) in the degradation process, followed by surface-bound hydroxyl radicals (OHsurface), superoxide radicals (O2−) and ultimately by singlet oxygen radicals (1O2). The study's economic analysis demonstrated that using microwave mode of heating for catalyst synthesis is both green and cost-effective. This observation suggests the possibility of practical implications in the domain of dye degradation.

Agricultural low-cost waste adsorption of methylene blue and modelling linear isotherm method versus nonlinear prediction

AbstractThis study shows that geographically marked wheat hull, named Siyez, rice hull Sarı Kılçık, and Taşköprü Garlic stalk were used as agricultural waste to potential adsorbent materials for removing methylene blue from aqueous solution. Experimental data were evaluated in both equilibrium batch process and kinetic studies. In addition, the factors that affect the adsorption capacities, such as pH solutions, methylene blue concentration, contact time, and temperatures, were also investigated. Obtained data were subject to two constant adsorption models of Langmuir, Freundlich, Temkin, and Dubinin−Radushkevich. The kinetic models (pseudo-first-order, pseudo-second-order, intra-particle diffusion and film diffusion) and thermodynamic parameters were evaluated. The adsorption isotherms, characterized by an excellent fit with the Langmuir model (R2 = 0.99) across all adsorbents, underscore the prevalence of monolayer adsorption of methylene blue, in contrast to the Freundlich equation. Adsorption kinetics of the methylene blue onto the adsorbents followed pseudo-second-order kinetic model. According to high regression coefficient (R2) and minimal values of nonlinear error functions like RMSE; the maximum monolayer adsorption capacities of wheat hull, rice hull and garlic stalk were found to be 62.50 (mg/g), 54.94 (mg/g), and 370.37 (mg/g), respectively. The results indicated that these proposed adsorbents could be low-cost and effective adsorbents for water purification and have adsorption capacity as much as comparable with the literature. In batch equilibrium studies, the adsorption of methylene blue dye onto the wheat hull, rice hull, and garlic stalk exhibited a significant correlation with temperature, contact time, and initial concentration of methylene blue dye and Adaptive Neuro-Fuzzy Inference System algorithm for forecasting overall the system parameter well fitted with these findings with the accuracy of outputs (R2 about 0.99 for each). Consequently, the thermodynamic analysis revealed that the adsorption process takes place in bulk diffusion by liquid phase mass transfer and occurred spontaneously with endothermically except garlic stalk. Adsorption thermodynamic studies show that the adsorption of methylene blue onto the garlic stalk was spontaneous and exothermic. Graphical Abstract

Waste-Derived Carbon Nano-Onions for the Removal of Organic Dye from Wastewater and Phytotoxicity Studies.

Dyes are extensively employed in industries, namely, textiles, cosmetics, paper, pharmaceuticals, tanning, etc. The effluent released from these industries contains various kinds of harmful dyes that adversely impact living beings and the environment due to their recalcitrant and toxic nature. In this study, an effort has been made to eliminate the methylene blue (MB) from wastewater using carbon nano-onions (CNOs) produced from waste frying oil (WFO) using an economical and eco-friendly wick pyrolysis method. The impact of process variables, namely, pH, temperature, process time, MB dye concentration, and adsorbent, was examined for optimum dye removal. The dye removal efficiency (RE) of 99.78% was obtained in 20 min under optimum conditions. The pseudo-second-order model demonstrated a better kinetic fitting with the experimental data. The Langmuir model represented the maximum adsorption capacity (q max) of 43.11 ± 2.56 mg g-1. The regeneration studies demonstrated that the CNOs achieved ∼99.6% MB dye removal over three cycles. Brassica nigra seeds irrigated in treated wastewater showed better growth (3.29 cm) than untreated dye wastewater, which confirms the environmental sustainability of the overall process.

Preparation magnetic graphene oxide/diethylenetriamine composite for removal of methylene blue from aqueous solutions

Graphene oxide (GO) and its derivatives have several applications in many areas such as environmental and energy materials, water treatment and biomedical technologies. Because of having various polar groups on its surface, GO is considered as an excellent adsorbent. However, for many applications such as adsorption of pollution from aqueous solutions, chemical functionalization of graphene oxide is often a necessary requirement. In the present study, a new composite from graphene oxide, diethylenetriamine (DETA) and silica coated MnFe2O4 nanoparticles (GO/DETA/MnFe2O4@SiO2) was prepared. The structure, thermal stability and magnetic properties of the composite were studied by FT-IR, XRD, SEM, EDS, VSM and TGA spectroscopic methods. The prepared composite showed magnetic property with a saturation magnetization of 3.0 emu/g. The adsorption properties of GO/DETA/MnFe2O4@SiO2 composite for methylene blue (MB) in aqueous solution were studied using batch method. The effects of important parameters on the surface adsorption process of MB, including pH, contact time, adsorbent dosage and initial dye concentration were investigated. The adsorption isotherm was in accordance with Langmuir model showing surface homogeneity of the adsorbent. According to the Langmuir analysis, the maximum adsorption capacity (qm) of GO/DETA/MnFe2O4@SiO2 composite for MB was found to be 243.91 mg/g. The kinetic studies showed that the adsorption was pseudo first-order process. In addition, the thermodynamic studies indicated the adsorption was spontaneous and endothermic process.

A Novel Nanogold Composite Fabrication, Its Characterization, and Its Application in the Removal of Methylene Blue Dye from an Aqueous Solution

A unique aspect of this research lies in the combination of polyethylene terephthalate (PET) nanofibers with Auo@PPh2-PIILP to create a nanogold composite (NGC). This NGC has proven to be highly efficient in removing methylene blue (MB) from wastewater. The prepared nanogold composite NGC was characterized by Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDAX), and Elements Distribution Mapping (EDM). Several factors were examined in batch adsorption experiments to determine their impact on dye adsorption. These factors included the initial pH range of four to eight, the dosage of NGC adsorbent ranging from 0.001 to 0.008 g, the initial concentration of MB dye ranging from 10 to 50 mg L−1, and the contact period ranging from 10 to 80 min. It has been observed that NGC is more efficient in removing MB from polluted water. The results of the pseudo-second-order model show good agreement between the calculated adsorption capacity (qe)cal. (4.3840 mg g−1) and the experimental adsorption capacity (qe)exp. (4.6838 mg g−1) values. Experimental findings suggest a monolayer capping of MB dye on the NGC surface with a maximum adsorption capacity Qm of 18.622 mg g−1 at 20 °C, indicating that it is well-fitted to the Langmuir isotherm.

A new nanocomposite as adsorbent and catalyst for enhanced removal of methylene blue

In this study, we present, for the first time, the preparation and characterization of a few-layer graphene (FLG)/Fe3O4/Ag nanocomposite functionalized with polyacrylic acid (PAA) polymer for the removal of methylene blue (MB). X-ray Powder Diffraction (XRD) analysis confirmed the coexistence of Fe3O4 and Ag nanoparticles. The results demonstrate a high adsorption ability (qmax 141.60 mg/g) of the nanocomposites, achieving 98% removal of MB dye within 40 min at a concentration of 50 mg/L, with a nanoadsorbent amount of 100 mg. Furthermore, the findings indicate that the FLG/Fe3O4/Ag@PAA adsorbent maintains high dye removal efficiency over four consecutive cycles. The FLG/Fe3O4/Ag@PAA nanocomposites exhibit significantly enhanced catalytic reduction activity on organic pollutants. The reduction of MB can be completed in 300 s in the presence of NaBH4 as a reducing agent, using 5 mg of nanocatalyst and a concentration of MB dye of 50 mg/L. These results suggest that the nanocomposite can serve not only as an adsorbent but also as a promising catalyst for the reduction of organic dyes.

Green algae Ulva lactuca-derived biochar-sulfur improves the adsorption of methylene blue from water

The present investigation explores the efficacy of green algae Ulva lactuca biochar-sulfur (GABS) modified with H2SO4 and NaHCO3 in adsorbing methylene blue (MB) dye from aqueous solutions. The impact of solution pH, contact duration, GABS dosage, and initial MB dye concentration on the adsorption process are all methodically investigated in this work. To obtain a thorough understanding of the adsorption dynamics, the study makes use of several kinetic models, including pseudo-first order and pseudo-second order models, in addition to isotherm models like Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich. The findings of the study reveal that the adsorption capacity at equilibrium (qe) reaches 303.78 mg/g for a GABS dose of 0.5 g/L and an initial MB dye concentration of 200 mg/L. Notably, the Langmuir isotherm model consistently fits the experimental data across different GABS doses, suggesting homogeneous adsorption onto a monolayer surface. The potential of GABS as an efficient adsorbent for the extraction of MB dye from aqueous solutions is highlighted by this discovery. The study’s use of kinetic and isotherm models provides a robust framework for understanding the intricacies of MB adsorption onto GABS. By elucidating the impact of various variables on the adsorption process, the research contributes valuable insights that can inform the design of efficient wastewater treatment solutions. The comprehensive analysis presented in this study serves as a solid foundation for further research and development in the field of adsorption-based water treatment technologies.

Adsorption Performance of Acidic Modified Fly Ash: Box–Behnken design

Fly ash (FA) and modified fly ash (mFA) were used as adsorbents to remove methylene blue (MB) dye from aqueous solutions. The adsorbents were characterized using crystal structures with XRD, surface functional groups with FTIR, and surface morphologies with SEM. Response surface methodology (RSM) with Box-Behnken design (BBD) was used to optimize adsorption parameters such as MB dye concentration (A: 10-20 mg/L), solution pH (B: 3-11), and contact time (C: 30-180 min). ANOVA analysis shows the significant inter-actions between initial concentration, solution pH value, and solution pH value, contact time was found to be significant in the removal of MB (p-value=&amp;lt; 0.0001, 0.0040), whereas between the effect of initial concen-tration and contact time was not significant (p-value = 0.0881). The adsorption kinetics followed the pseudo-second-order (PSO) kinetic model and the adsorption isotherm followed the Langmuir model. At 28°C, the adsorption capacity of fly ash-HNO3 for MB was found to be 7.67 mg/g.

Dye adsorption onto iron oxide prepared by green method mediated by leaf extract of Falcaria vulgaris

ABSTRACT Iron oxide nanoparticles were green synthesised by Falcaria vulgaris extract. Characterisation of samples was carried out by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Investigating factors, such as pH, adsorbent dosage, temperature, contact time and the dose effect of the initial concentration of methylene blue dye, was done on adsorption of methylene blue. The synthesised nanoparticles exhibited a relatively spherical and irregular surface, with a size of about 35 nm, a haematite crystal phase and a saturation magnetisation of 8.3 emu/g. The highest adsorption of methylene blue (76%) was achieved at a pH value of 6, with an optimal adsorbent quantity of 0.004 g/L and a starting concentration of 80 mg/L. The adsorption behaviour of synthesised iron oxide nanoparticles follows from Langmuir isotherm and has a maximum adsorption capacity of 49.169 mg/g. The kinetics of methylene blue dye removal using iron oxide nanoparticles followed a second-order kinetic equation. The adsorption activity of iron oxide nanoparticles showed very little change even after two regeneration cycles. Therefore, the obtained adsorbent regained its adsorption capacity with the help of the photo-Fenton process and is reusable again.

Chitosan-ZnO Composite for Removal of Methylene Blue

This study aims to determine the effectiveness and increase in absorption of the chitosan-ZnO composite in the process of removing methylene blue when using the photodegradation method with the help of a UV lamp. Chitosan was synthesized from shrimp shell waste composite with metal oxide ZnO. The results of the characterization using XRD obtained the diffraction peak for chitosan at an angle of 2θ, namely 19.85°; 29.43°; 34.76° and chitosan-ZnO composite at an angle of 20.18°; 28.93°; 33.57°. The SEM-EDX characterization shows that chitosan-ZnO has small, light-colored grains and more gaps and contains elements of chitosan and Zn. In the FTIR characterization, there was a decrease in intensity at a peak of around 3360 cm1 which was caused by the chitosan-ZnO composite producing OH groups which reacted with methylene blue dye. In testing the effect of contact time using a UV lamp, there was an increase in the percentage of degraded methylene blue compared to without using a UV lamp. The maximum contact time is obtained at 60 minutes. While testing the effect of methylene blue dye concentration, the maximum absorption concentration was 45 ppm at 60 minutes of contact time. The adsorption capacity of the composite against methylene blue dye without UV light was 18.91 mg/g while using a UV lamp it increased to 20.145 mg/g. Based on this research, the chitosan/ZnO composite can be used quite well as a methylene blue dye remover.

Adsorption characteristics of magnetized biochar derived from Citrus limetta peels

Agro-industrial waste is an alarming issue that needs to be addressed. Waste valorization is an effective technique to deal with such effectively. Synthesis of biochar from fruit waste is one of the emerging approaches for adsorption, energy storage, air purification, catalysis, and biogas production trending these days. Magnetized Citrus limetta biochar (MCLB) was synthesized from Citrus limetta peels and was magnetized using iron oxide. Magnetization of biochar increases its functionalities as well as makes its separation easy. The removal of Methylene Blue (MB) dye from an aqueous solution is achieved through the use of MCLB. Methylene Blue is a prominent and widely used cationic-azo dye in the textile and printing industries. The accumulation of MB in wastewater is the major problem as MB is reported as a carcinogenic agent. The removal of MB dye with MCLB was analyzed by adsorption studies, wherein the effect of factors influencing adsorption such as initial concentration of MB dye, MCLB dosage, the effect of pH, contact time, and adsorption isotherms were studied. Characterization of MCLB was carried out using various techniques, such as FTIR, VSM, XRD, SEM, RAMAN, and Zeta potential. The adsorption isotherm mechanism was well explained with the non-linear Langmuir isotherm model resulting in a good adsorption capacity (qe = 41.57 mg/g) of MCLB when MB (co = 60 mg/L, pH ~ 6.8, T = 273K). The thermodynamics analysis revealed that MB's spontaneous and endothermic adsorption onto the MCLB surface followed pseudo-second-order kinetics. The results obtained from this study suggest that the magnetized biochar derived from Citrus limetta peels has a wide range of potential applications in the treatment of dyeing wastewater.

Experimental investigation of H3PO4 activated papaya peels for methylene blue dye removal from aqueous solution: Evaluation on optimization, kinetics, isotherm, thermodynamics, and reusability studies

This investigation is centered on the effectiveness of methylene blue (MB), a cationic dye, adsorbed from an aqueous media by H3PO4 activated papaya skin/peels (PSPAC), with initial pH (2–10), contact time (30–180 min), MB dye concentration (varying from 10 to 50 mg/L), and MB dose (0.1–0.5 gm). The findings show that the best optimal conditions for MB dye removal occur at a 6 pH, 0.3 gm dose of PSPAC adsorbent for 10 mg/L MB dye concentration, with 90 min of contact time. To optimize and validate the extraction efficiency of MB dye, a response surface methodology (RSM) study was conducted using a central composite design (CCD) with a regression model showing R2 = 0.9940. FT-IR spectroscopy shows, CO, and O–H stretching functional groups while FE-SEM is assessed to supervise morphological features of the PSPAC adsorbent. The peak adsorption capacity with 46.95 mg/g for the Langmuir isotherm model conveniently satisfies the adsorption process with R2 = 0.9984 while with R2 = 0.999, a kinetic model, pseudo-second-order, confirms MB dye adsorption by PSPAC adsorbent. Moreover, thermodynamic parameters including ΔGᵒ, ΔH°, and ΔS° were computed and found to be spontaneous and exothermic. Furthermore, regeneration studies employed with NaOH (0.1 M) and HCl (0.1 M) solution media show an acceptable MB removal efficiency consecutive up to three cycles. The study highlights that H3PO4 papaya skin/peel (PSPAC) is an effectual, sustainable, reasonably available biosorbent to remove industrial cationic dyes disposal.

Improved methylene blue adsorption from an aqueous medium by ozone-triethylenetetramine modification of sawdust-based biochar

In this study, sawdust biochar-O3-TETA (SDBT), a novel biochar, was prepared via treatment with 80% sulfuric acid, followed by oxidation by ozone and subsequent treatment with boiling Triethylenetetramine (TETA). Characterization studies of the prepared SDBT adsorbent were performed with SEM–EDX, BET, XRD, BJH, FT-IR, DTA and TGA analyses. The adsorption efficiency of MB dye by SDBT biochar from water was investigated. Methylene Blue (MB) dye absorption was most effective when the solution pH was 12. The maximum removal % of MB dye was 99.75% using 20 mg/L as starting MB dye concentration and 2.0 g/L SDBT dose. The Qm of the SDBT was 568.16 mg/g. Actual results were fitted to Temkin (TIM), Freundlich (FIM), and Langmuir (LIM) isotherm models. The experimental results for SDBT fitted well with all three models. Error function equations were used to test the results obtained from these isotherm models, which showed that the experimental results fit better with TIM and FIM. Kinetic data were investigated, and the pseudo-second-order (PSOM) had R2 > 0.99 and was mainly responsible for guiding the absorption rate. The removal mechanism of the MB dye ions in a base medium (pH 12) may be achieved via physical interaction due to electrostatic interaction between the SDBT surface and the positive charge of the MB dye. The results show that SDBT effectively removes the MB dye from the aqueous environment and can be used continually without losing its absorption efficiency.

Dialdehyde cellulose/gelatin hydrogel as a packaging material for manganese oxides adsorbents for wastewater remediation: Characterization and performance evaluation

The dialdehyde cellulose (DC) was used to synthesize gelatin-cellulose dialdehyde by Schiff base as a packaging material to manganese oxides nanoparticles adsorbents (Mn oxides@DC/Gel) for wastewater remediation and support the antimicrobial behavior of gelatin and DC. The crystallinity index% of microwave-synthesized DC prepared from cellulose II decreased from 43.18% to 34.11% and its oxidation degree was 143.77%. The greenly-produced Mn oxides were studied by XRD and TEM. XRD verified the presence of two different phases of α-MnO2 and α-Mn2O3 in the form of nanorods and nanocubes. Mn oxides@DC/Gel was investigated by FT-IR, XRD, XPS, SEM, swelling absorptivity, and thermal analysis. The optimal swelling ratio% of Mn oxides@DC/Gel nanocomposite was 1494.04±16.65%. The influence of pH on swelling ratios verified the instability of the imine group in acid and basic media. Mn oxides@DC/Gel nanocomposite hydrogel causes approximately two-fold greater inhibitory zones than gentamicin. The optimal adsorption conditions were adsorbent dose (0.05g), pH (9.0), contact time (120 min), and methylene blue dye concentration (30mg/L). The maximum adsorption capacity of Mn oxides@DC/Gel nanocomposite was 51.06±1.0 mg/g. The adsorption by Mn oxides@DC/Gel nanocomposite agrees with Langmuir, Redlich–Peterson, and Freundlich mechanisms.

Biosorption of methylene blue by lentil shell on activation with sulfuric acid, formaldehyde, and calcination: kinetic, isotherm, and thermodynamic study

Lentil shell (LS) on modification with sulfuric acid (LSAC), formaldehyde (LSFM), and on calcination (LSCL) were used for the adsorption of methylene blue dye in the present study. The sulfuric acid treated LS adsorbent has shown maximum adsorption. The batch adsorption experiments were studied with the effect of adsorbent dose (10–60 mg), pH (4–10), dye concentration (10–80 mg/L), contact time (10–60 minutes), and temperature (303–333 K). The maximum removal of methylene blue was found at pH 10 with adsorption time 60 minutes. The maximum adsorption capacity is measured for LSAC, LSCL, LSFM, and LS untreated (LSUN) are 49.56, 45.79, 42.24, and 42.09 mg/g respectively for 60 mg adsorbent dose with 60 mg/L of initial methylene blue dye concentration. The biosorbents were characterized with Fourier Transform Infrared spectra, Scanning Electron Microscopy, Transmission Electron Microscopy, BET-N2 adsorption, and Energy Dispersive X-ray analysis. The adsorption isotherm was studied at the temperature of 303, 313, 323, and 333 K. It was found that the higher temperature suitable for maximum adsorption. Langmuir model and Freundlich model were studied from the obtained results for adsorption mechanism. The pseudo second order kinetic model was found suitable for the present adsorption study in comparison with pseudo first order model and intraparticle diffusion model. The data obtained from the present work showed that LS could be employed as an efficient adsorbent for the adsorption of the dye.