Methylene Blue Removal Research Articles

One-dimensional magnetic chains for methylene blue removal.

Adsorption is a promising method for the treatment of wastewater from the dyestuff industry due to its simplicity, high efficiency, low energy consumption and no secondary pollution. The capacity to separate adsorbents in a timely and efficient manner is a crucial factor in industrial applications. One-dimensional magnetic chains modified with polydopamine and in situ generated Ag nanoparticles (MC@PDA-Ag) were fabricated as highly regenerable adsorbents for methylene blue (MB). The magnetic chains were characterized by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption, X-ray photoelectron spectrometry, X-ray diffraction and magnetometry. The adsorption and catalytic degradation of MB by the materials were investigated. The regeneration capacity of MC@PDA-Ag was also evaluated. The specific saturation magnetization of MC@PDA-Ag is 38.2 emu g-1. The adsorption capacity of MC@PDA-Ag remained 76% of the initial value after 12 cycles of adsorption and elution. The novel adsorbents, which integrate adsorption and catalytic degradation, are anticipated to facilitate the development of magnetic adsorption materials for the remediation of dye pollution.

Exploiting the efficiency of narrow band gap S-doped g-C3N4/Expanded Perlite/Red Ocher nanocomposite for high-level eliminating halogenated dye in Cool‐White‐SMD/H2O2 system

Hitherto, constructing prominent visible-light-driven g-C3N4/soil composites still suffers from several intricacies, including low specific surface area, inadequate charge separation, and a high band gap energy (Eg >2.7 eV). To address these drawbacks, sulfur atoms were introduced into g-C3N4 (S-doped g-C3N4 or SCN); thereby, Red Ocher (RO) and Expanded Perlite (EP) were grafted to SCN, which the engineered SCN/10EP/20RO nanocomposite divulged a higher specific surface area, further light-harvesting capability, narrower Eg, prolonged charge recombination process, lower the charge transfer resistance, and higher photocurrent density than bulk g-C3N4 (CN). Additionally, the formed S-scheme charge migration mechanism and the hole-trapping role of the hydroxyl functional groups synergistically engendered robust visible-light-driven catalytic performances under visible-light exposure. By enabling the heterogeneous photo-Fenton-like process, the Methylene Blue removal efficiency (MBRE) and the Total Organic Carbon (TOC) decontamination promptly elevated to 99.6% and 87.7% within 90 min under Cool-White-SMD/H2O2 condition, respectively. Manifestly, the kinetic reaction rate of the photo-Fenton-like process was 7.5 times higher than the primary photocatalysis, showcasing HO•had a determining role towards decent decomposing MB. After overviewing, our detailed findings straightforwardly corroborated that SCN/10EP/20RO nanocomposite would be an efficient, long-lasting, and green photocatalyst for eradicating halogenated organic pollution.

Improved Cupressus sempervirens L. galls for methylene blue removal: adsorption kinetics optimisation using the DA-LS algorithm, characterisation, and machine learning modeling

ABSTRACT In this study, an investigation was conducted on the effectiveness of three bioadsorbents – galbuli of Cupressus sempervirens L. almond shells, and Luffa – for removing methylene blue (MB) from water. Various activation techniques and operational conditions were employed to enhance the adsorption capacity. The study focused on adsorption kinetics and equilibrium capacity. The results showed that microwave-dried galbuli of Cupressus sempervirens L. exhibited the highest adsorption capacity of 38.05 mg/g with an adsorption efficiency of 17.4%. To improve this capacity, the Dragonfly Algorithm-integrated least squares (DA-LS) was proposed to optimise the fitting of 32 adsorption isotherm models, which included a proposed modified Langmuir model. After optimisation, the sixth chemical treatment of Cupressus sempervirens L. reached a Langmuir isotherm qmax value of 84.44 mg/g, suggesting the high efficiency of the bioadsorbent compared to previous studies. Characterisation using microscopy and ATR-FTIR techniques revealed that chemical modifications led to rougher, microporous cellulose fibres and significant changes in the chemical structure, potentially enhancing the surface area and adsorption efficiency. To predict the adsorption capacity, the Support Vector Machine for Regression with DA (SVMR-DA) was utilised, achieving a root mean square error (RMSE) of 1.357 and an R2 of 0.9913. This high accuracy indicates a reliable model with a robust error distribution. These results suggest that Cupressus sempervirens L. can be an effective bioadsorbent for water treatment, with significant potential for industrial application.

Calcined biomass-bentonite composites as eco-friendly adsorbents for the treatment of toxic anionic and cationic dye wastewater

Adsorption is a suitable technique for decontamination of organic dye wastewaters. Herein, we comparatively investigated the adsorption performance of bentonite (BEN) and its modification with groundnut shell (BGS) and palm kernel shell (BPS) for methylene blue (MB) and congo red (CR) dyes removal from aqueous solution. BGS and BPS were prepared by calcination at 300 °C for 6 h and were characterized using BET, SEM, EDS and FTIR to determine their textural properties, morphologies, elemental compositions, and functional groups. The BET surface examination revealed that the surface area of BEN was enhanced from 78 m2/g to 195 m2/g and 141 m2/g after modification with groundnut shell (BGS) and palm kernel shell (BPS), respectively. The adsorption process in a batch system was subjected to comprehensive experimentation to investigate the effect of adsorbent dosage, contact time, temperature, initial concentration, and pH. The adsorption was fitted to adsorption isotherm and kinetic models and the results revealed that the adsorption process of BEN, BGS, and BPS towards MB and CR adsorption can be best described by Temkin, Freundlich and pseudo-second order kinetic models. The adsorption capacities (qmax) for uptake of MB by BEN, BGS and BPS are 10.61, 10.85 and 10.93 mg, while CR exhibited 8.83, 6.87 and 5.86 mg/g, respectively. The thermodynamics study revealed that the adsorption process was spontaneous, feasible, endothermic in nature. The adsorption process is governed by electrostatic attraction with the involvement of physical and chemical adsorption. This study suggests that biomass-modified bentonite is a sustainable, cost-effective, non-toxic, and greener approach for eliminating MB and CR from aqueous solution. Furthermore, the modification method does not only achieve substantial removal of MB and CR dyes, but also offers considerable energy savings and operational cost reductions in real-time based on water quality data. This study does present a novel, sustainable approach to improve natural water treatment efficiency and compliance.

A novel approach for the modification of eggshell powder and its application for lead and methylene blue removal

Water pollution is one of the major concerns due to rapid industrialization and urbanization. Wastewater treatment has been an area of great interest for the researchers and among many technologies developed for water treatment, adsorption is the most preferred due to its efficiency and ability of been economical method. In this research, eggshell powder (ESP) is converted into modified eggshell powder (MESP) through chemical and thermal treatment (at 550 °C for 2 h) to use it as an adsorbent to remediate Pb2+ and Methylene blue (MB) from water, then it is transferred into modified eggshell powder magnetic composite (MESPMC) with iron coating to resolve the separation challenges and to boost the MESP's adsorption efficiency. FTIR analysis identified the functional groups of ESP, MESP, and MESPMC. XRD analysis reveals a hexagonal crystal structure of calcite in MESP and a combination of the hexagonal crystal structure of calcite and the cubic crystal structure of iron in MESPMC. The Scherrer equation is used to determine the average crystallite sizes of MESP and MESPMC, which are 22.59 nm and 12.15 nm, respectively. The SEM image shows the irregular shape of the MESP and MESPMC particles, as well as the active coating layer in MESPMC. EDX analysis reveals that Ca (20.92 %), O (56.83 %), and Fe (41.03 %), O (48.83 %) are the most abundant elements in MESP and MESPMC respectively. TGA analysis points out that MESPMC outperforms MESP in terms of thermal stability between 600 and 750 °C. MESP and MESPMC were found to be very efficient adsorbent for lead and methylene blue in aqueous medium. At 40 mg/mL adsorbent dosage, ESP, MESP, and MESPMC had the highest yields of Pb2+ removal, with 46.996 %, 99.27 %, and 99.78 % respectively at 200 rpm for 60 min with 25 °C. Furthermore, at the 0.5 mg/mL adsorbent dosage, ESP, MESP, and MESPMC have the maximum removal efficiency of methylene blue, with 47.19 %, 90.1 %, and 92 %, respectively at 200 rpm for 30 min with 25 °C. In both cases, the removal efficiency of MESPMC is slightly higher than that of MESP and much higher than that of ESP. Additionally, the results confirm that MESP and MESPMC are potential environment-friendly bio sources to remediate heavy metal (Pb2+) and methylene blue dye from water.

Enhanced Dye Adsorption on Cold Plasma-Oxidized Multi-Walled Carbon Nanotubes: A Comparative Study.

The oxidation of multi-walled carbon nanotubes (MWCNTs) using cold plasma was investigated for their subsequent use as adsorbents for the removal of dyes from aqueous solutions. The properties of MWCNTs after plasma modification and their adsorption capacities were compared with pristine and chemically oxidized nanotubes. The modification process employed a reactor where plasma was generated through dielectric barrier discharges (DBD) powered by high-voltage nanosecond pulses. Various modification conditions were examined, such as processing time and pulse voltage amplitude. The degree of oxidation and the impact on the chemistry and structure of the nanotubes was investigated through various physicochemical and morphological characterization techniques (XPS, BET, TEM, etc.). Maximum oxidation (O/C = 0.09 from O/C = 0.02 for pristine MWCNTs) was achieved after 60 min of nanopulsed-DBD plasma treatment. Subsequently, the modified nanotubes were used as adsorbents for the removal of the dye methylene blue (MB) from water. The adsorption experiments examined the effects of contact time between the adsorbent and MB, as well as the initial dye concentration in water. The plasma-modified nanotubes exhibited high MB removal efficiency, with adsorption capacity proportional to the degree of oxidation. Notably, their adsorption capacity significantly increased compared to both pristine and chemically oxidized MWCNTs (~54% and ~9%, respectively). Finally, the kinetics and mechanism of the adsorption process were studied, with experimental data fitting well to the pseudo-second-order kinetic model and the Langmuir isotherm model. This study underscores the potential of plasma technology as a low-cost and environmentally friendly approach for material modification and water purification.

Insight into adsorption-desorption of methylene blue in water using zeolite NaY: Kinetic, isotherm and thermodynamic approaches

It is critical to find an efficient method to separate methylene blue (MB) in wastewater before discharging them into environment. Adsorption using zeolites is the most commonly used one. To determine adsorption mechanism providing useful data to enhance adsorption capacity and practicability of scale-up, kinetic, isotherm and thermodynamic adsorption were evaluated and discussed intensely. Zeolite NaY was synthesized from rice husk ash with a one-stage process. Effects of pH, contact time, initial concentration, adsorbent dose, temperature, solvents and recyclic stability on MB adsorption and desorption were investigated in detail via alternating variable method. Optimal conditions for adsorption were at pH 8, 1 h, 50 mgMB/L, 303K. Adsorption kinetics and isotherms showed that the process fitted to pseudo-second-order, Freundlich and Temkin isotherm, indicating a spontaneous, exothermic and physical adsorption process with multilayer adsorption. Desorption process showed that EtOH:H2O (1:1) solvent at 323K was optimal for releasing MB and its thermodynamic studies revealed that this process was favorable with rising temperature. The maximum adsorption capacity was calculated as 49 mg/g and the adsorbent could maintain its adsorption performance after six cycles. Generally, this study provided a comprehensive approach of an efficient, cost-effective, and recyclable NaY for MB removal from water.

A strategy for the efficient removal of acidic and basic dyes in wastewater by organophilic magadiite@alginate beads: Box-Behnken Design optimization

In this study, four adsorbents were developed: layered silicate magadiite material (mag), Hexadecyltrimethylammonium intercalated magadiite (HDTMA@mag), a cross-linked composite of sodium alginate and magadiite (ALG@mag) and a cross-linked composite of sodium alginate and HDTMA@magadiite (ALG@HDTMA@mag). The adsorbents were evaluated for their effectiveness in removing of Methylene Blue (MB) and Eriochrome Black T (EBT) dyes. The prepared adsorbents were characterized using SEM, XRD, FTIR, and zeta potential measurements. Kinetic modeling results indicated that both film diffusion and intraparticle diffusion are useful as rate-determining processes in adsorption for all adsorbents. For both dyes, the Langmuir isotherm model provided a good correlation with the adsorption equilibrium data. ANOVA analysis for the best adsorbent (ALG@HDTMA@mag beads) revealed that MB removal was significantly influenced by the positive individual effects of contact time and ALG@HDTMA@mag dose. However, the individual effect of MB concentration exhibited an antagonistic effect throughout the adsorption process. The optimal parameters for achieving an adsorption capacity of 118.54 mg/g were a dye concentration of 60 ppm, a contact period of 1800 min, and an ALG@HDTMA@mag dose of 50 mg.

Cr-substituted Mn–Zn ferrite nanoparticles: A study of optical, photocatalytic degradation, and radiation shielding evolution

In this work, we investigate the impact of chromium (Cr) additives on the optical, photocatalytic degradation and the radiation attenuation features of chromium-manganese (Mn)-zinc (Zn)-based spinel nanoferrite (named MZCF-nanoferrites. The Kubelka-Munk approach of reflectance results and Tauc's plots were exploited to verify the energy gap (Eg) of the MZCFx ferrite nanoparticles. The nanoferrites MZCF0, MZCF1, MZCF2, MZCF3, MZCF4, and MZCF5 have Eg values 1.826, 1.811, 1.797, 1.784, 1.772, and 1.769 eV, respectively. The comparative study of the photocatalytic degradation for the optimal (Mn0.8Zn0.2Cr0.1Fe1.9O4) nanoferrite sample and many reported photocatalytic materials evidenced that the MZCF5 nanoferrite has methylene blue dye removal ability higher than those materials (96.38 %, in 60 min). Moreover, this comparative study showed the improved photocatalytic degradation stability performance of the present nanoferrites (just 1.65 % efficiency was decreased after five cycles). The present study proposes a novel approach toward spinel nanoferrites, focusing on the optical and photocatalytic characteristics of the MZCFx-nanoferrites that can be applicable in water treatment fields. Examining linear attenuation coefficient (LAC) of MZCFx-nanoferrite at 0.662 MeV, we observe increased LAC values 0.286 cm−1 to 0.344 cm−1 with increasing Cr additions. Conversely, the half value layer (HVL) values at 0.662 MeV decreased 2.421 cm–2.017 cm with increasing Cr additions. By comparing the HVL values of the MZCFx-nanoferrites at 0.662 MeV to some selected radiation shielding materials, the HVL of the MZCFx-nanoferrites showed smaller values. These findings offer promising perspectives for optimization of spinel nano materials for use in radiation shielding applications.

The interaction of light with oxygen-vacancy-rich W18O49 nanoparticles synthesized using different acid molarities for acidic and neutral water treatments

Toxic industrial compounds as a global difficulty can adversely impact people's health and the environment which motivates studies on the interaction of light and metal oxide nanoparticles to treat the water through adsorption or photocatalysis mechanism by nanoparticles. In the paper, oxygen-vacancy-rich W18O49 nanorods are successfully synthesized by a facile one-pot hydrothermal method using different molarities of hydrochloric acid (HCl) (2–12 M) as proposed candidates to treat the wastewater and solve the global difficulty related to treating the acidic water. The results declare that the change in acid molarity leads to noteworthy changes in the characteristic properties of the produced W18O49 nanorods, and the lowest acid molarity (2 M) causes the formation of uniform and pure monoclinic W18O49 nanorods with the high specific surface area (SSA) of 51.33 m2/g. Furthermore, the nanorods exhibit indirect and direct band gap energies in the range of 2.52–2.68 eV and 2.54–3.08 eV, respectively, as influenced by varying acid molarities (2–12 M). Furthermore, the impressive effects of acid molarity on the methylene blue removal efficiency of the nanorods under ultraviolet (UV) light are observed. The highest efficiency is obtained for W18O49 nanorods synthesized using the acid molarity of 2 M which can be explained by its high SSA, small band gap energy, generation of a large number of electron-hole pairs, and its efficient charge separation. The efficiencies of water treatment reach up to 99 % and 99.5 % at pH of 7 and 5, respectively, which is an excellent achievement and leads to proposing the mentioned W18O49 nanorods as an excellent candidate for treating wastewater and acid factory effluent which represents an appreciable breakthrough in addressing the issue.

Waste newspaper as cellulose resource of activated carbon by sodium salts for methylene blue and congo red removal

The work was aimed at evaluating the adsorptive properties of waste newspaper (WN) activated carbons chemically produced using sodium salts for methylene blue (MB) and congo red (CR) removal. The activated carbons, designated as AC1, AC2, AC3 and AC4 were prepared through impregnation with NaH2PO4, Na2CO3, NaCl and NaOH, respectively and activation at 500 °C for 1 h. The activated carbons were characterized for surface chemistry, thermal stability, specific area, morphology and composition. The AC1 with a surface area of 917 m2/g exhibits a greater MB capacity of 651 mg/g. Meanwhile, a greater CR capacity was recorded by AC2 at 299 mg/g. The pseudo-second order model fitted well with the kinetic data, while the equilibrium data could be described by Langmuir model. The thermodynamic parameters, i.e.., positive ΔH°, negative ΔG° and positive ΔS° suggest that the adsorption of dyes is endothermic, spontaneous and feasible at high solution temperature. To conclude, WN is a potential cellulose source for producing activated carbon, while NaH2PO4 activation could be employed to convert WN into activated carbon for effective dye wastewater treatment.

Surface‐Modified Mesoporous V2‐xSb2xO5‐δ Ceramics for Improving the Electrostatic Chemisorption of Methylene Blue

AbstractHerein, mesoporous V2‐xSb2xO5‐δ (Sb−V−O) compounds, encompassing a compositional range of x varying between, 0.05≤x≤0.08, with orthorhombic Pmmn space group symmetry, are synthesized by high‐temperature solid‐state reaction method. Scanning electron microscopy indicated the formation of microscale rods and flakes and EDS spectra affirmed the stoichiometric precision of their composition adhering to the formulated chemical formula. Nitrogen adsorption isotherms exhibited the distinctive type IV pattern, accompanied by an H3 hysteresis loop, signifying the formation of mesoporous micro rods and flakes. Brunauer‐Emmett‐Teller measurements demonstrated an augmented surface area, ranging from 16.67–28.74 m2/g, mirroring the effect of the increase in the concentration of Sb cations. The study demonstrated complete Methylene Blue dye removal within a brief 90 minute period, highlighting its efficacy in water remediation. The adsorption kinetics was aptly described by the pseudo‐second‐order model which exhibited a high degree of fit (R2=0.99). Freundlich adsorption isotherm was used to describe the multilayer adsorption of MB dye on the Sb−V−O surface indicating an exponential increase in adsorption active sites. Enhanced cationic MB dye adsorption on negative Sb−V−O surface is attributed to the electrostatic chemisorption by the interaction of NMe2+ on the negative surface modified Sb−V−O compounds.

Magnetically nanorized seaweed residue for the adsorption of methylene blue in aqueous solutions.

The cost-effective and green separation of dye pollutants from wastewater is of great importance in environmental remediation. Industrial seaweed residue (SR), as a low-cost cellulose source, was used to produce carboxylated nanorized-SR (NSR) via oxalic acid (OA)-water pretreatments followed by ultrasonic disintegration. Fourier transform infrared spectroscopy, X-ray polycrystalline diffraction, nitrogen isotherms, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, X-ray photoelectron spectrometry, particle charge detection, zeta potential and retro titration experiments were utilized to explore the physiochemical properties of samples. The NSRs with carboxyl content of 4.58-6.73 mmol g-1 were prepared using 10-60% OA-water pretreatment. In the case of 20% OA-water pretreatment, the highest NSR yield (73.9%) and nanocellulose content (80.2%) were obtained. Through self-assembly induced by the electrostatic interaction, magnetic NSR composite adsorbents (MNSRs) were prepared with the combination of NSR and Fe3O4 nanoparticles (NPs). The carboxylated NSR with negative charge demonstrated good affinity for Fe3O4 NPs. The Fe3O4 NPs were perfectly microencapsulated with the NSR when the NSR/Fe3O4 mass ratio was higher than 1/1. The adsorption properties of the MNSR for methylene blue (MB) removal from aqueous solution were investigated. The adsorbent with NSR/Fe3O4 mass ratio of 1/1 (MNSR1/1) exhibited optimum performance in terms of the magnetic properties and adsorption capacity. The MNSR1/1 showed high adsorption ability in a pH ≥7 environment. According to the Langmuir fitting, the maximum adsorption capacity of MNSR1/1 for MB reached 184.25 mg g-1. The adsorption of MB complies with the pseudo-second-order kinetic model. MNSR1/1 still maintained good adsorption properties after the fifth cycle of adsorption-desorption. MNSR1/1 could selectively adsorb cationic dye (i.e., MB and methyl violet) from wastewater, with hydrogen bonding and electrostatic interaction as the main force.

Stable and effective photo-Fenton catalysts of Fe-alginate/PVDF composite electrospun nanofibers for the removal of methylene blue

Stable and effective photo-Fenton catalysts of Fe-alginate/PVDF composite electrospun nanofibers for the removal of methylene blue

Fabrication of Ag-doped BiOF-reduced graphene oxide composites for photocatalytic elimination of organic dyes

Bismuth oxyfluoride (BiOF) is an emerging class of material with notable chemical stability, unique layered structure and striking energy band structure. Bi-based semiconductor materials and reduced graphene oxides (rGOs) have attracted considerable attention due to their broad spectrum of potential applications. Herein, we successfully synthesised an efficient photocatalyst comprising BiOF–rGO nanocomposites with embedded Ag nanoparticles using a simple hydrothermal method. The synthesised nanocomposites were characterised through Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy and ultraviolet (UV)–visible spectroscopy. The XRD results indicated the crystalline structures of the BiOF, Ag-doped BiOF and Ag-doped BiOF–rGO composites. Photocatalytic activity assessments focused on the degradation of methylene blue (MB) and methyl orange (MO) dyes under UV-light and sunlight irradiation. The Ag-doped BiOF–rGO composite exhibited significantly enhanced degradation efficiency, achieving 61.81 % and 74.25 % degradation of MB and MO, respectively, after 300 min under UV-light irradiation. On the contrary, pure BiOF demonstrated only 17.63 % and 48.29 % degradation for MB and MO, respectively, under similar conditions. Furthermore, under sunlight irradiation, the Ag-doped BiOF–rGO composite exhibited an MB removal efficiency of 43.87 % after 300 min, whereas pure BiOF showed only 27.47 % under identical conditions. These results underscore the potential of Ag-doped BiOF–rGO composites as highly efficient and adaptable photocatalysts for the photodegradation of organic dyes in industrial wastewater.

Steric and energetic investigations of adsorption isotherms of methylene blue on new polymeric multi-layered material-based k-carrageenan and alginate

In this research study, we examined the adsorption behavior of methylene blue (MB) on a novel biosorbent made of polyelectrolyte multilayers (PEM) biopolymeric material at three different temperatures. Various models derived from statistical physics formalism were employed to analyze the adsorption isotherms. An alternative approach based on the application of multilayer models from statistical physics theory was used to better investigate the adsorption mechanisms of MB on the PEM grafting material. We adjusted various parameters within this model across temperatures of 295K, 313 K, and333K, and these parameters played a crucial role in comprehending the adsorption mechanism. In addition, this approach revealed that the MB dye is linked through a multilayer process on the PEM grafting material with ‘non-parallel’ configurations and multimolecular process. The PEM grafting material showed maximum adsorption capacities ranging from 632.23 mg⁄g to 463.76 mg⁄g for the removal of MB over a pH of 6. The calculated adsorption energies ranged from 11.6 to 18.65kJ/mol, indicating that the MB adsorption process was primarily of a physisorption nature influenced by both hydrogen bonding and van der Waals interactions. Thus, the theoretical analysis indicated that this low-cost adsorbent material (PEM grafting) is a promising material for the removal of MB dye from the solution. Additionally, we examined the adsorption behavior by calculating the entropy, the free energy and the internal energy which govern the adsorption process of MB onto the PEM grafting material.

Date kernel biochar: A green approach to methylene blue removal from polluted water in Iraq

ABSTRACT This study investigated the potential use of biochar produced from Iraqi date kernels (Khestawi) as an adsorbent for methylene blue (MB) removal from polluted water. A full factorial design methodology was employed to examine the effects of heating rate, pyrolysis temperature and holding time on the performance of the produced biochar. The results showed that pyrolysis temperature and time had a strong effect on the biochar performance, while the heating rate had a weaker effect. The biochar produced at pyrolysis temperatures of 350°C and 550°C exhibited MB removal percentages (% R) of 48.9% and 30.9%, respectively. Similarly, biochar production through pyrolysis durations of 30 and 90 minutes resulted in MB removal rates of 47.5% and 30.3%, respectively. The adsorption experimental data was well-fitted by the Freundlich isotherm model, with a high value of the Freundlich constant (KF = 1.64), indicating a high adsorption capacity of the biochar. The activation of biochar using bio-oil (organic-1) led to a substantial enhancement in the adsorption capacity, with the activated biochar (ABC-1) exhibiting a higher adsorption capability and a higher value of the Freundlich constant (KF = 7.12). Overall, the results suggest that biochar produced from date kernels has the potential as an effective and sustainable adsorbent for MB removal from polluted water, with the potential for further enhancement through biochar activation.

Nanocarbons decorated TiO2 as advanced nanocomposite fabric for photocatalytic degradation of methylene blue dye and ciprofloxacin

In this research, C [graphene (Gr), multi-walled carbon nanotubes (MWCNTs), and single-walled carbon nanotubes (SWCNTs)] decorated TiO2 nanostructures were developed and further utilized to modify textile to achieve high-performance photocatalytic degradation of mixed water pollutants including methylene blue (MB) dye and pharmaceutical active compound, Ciprofloxacin (CPF) on solar radiation exposure (∼105 Lumens). The crystallite sizes of TiO2, TiO2-MWCNT, TiO2-SWCNT, and TiO2-Gr nanocomposites were observed in the 7.2–10.4 nm range. The bandgap, Eg of nanostructured C-TiO2, was observed in the 3.09–3.14 eV range. The photocatalytic performance of C-TiO2 showed almost complete removal of MB under the irradiation of the solar spectrum in just 120 min. Among C-based TiO2 nanocomposites, nanostructured TiO2-SWCNT showed the highest degradation efficiency of ∼98.86 % for MB dye. Further, the textile membrane showed a good degradation efficiency of 99.49 % for MB dye and 95.7 % for CPF within 120 min. An impressive removal efficiency of ∼93 % was observed for the mixture of MB and CPF solution due to a combination of several properties like surface groups (OH− & O2−), low charge recombination rate due to CNTs, and small crystal size. This proof-of-the-concept study can be the potential platform to manage water quality according to sustainability goals.

Efficacy of activated carbon using Salvadora persica stem for remediation of potentially toxic dyes from aqueous solution.

Potentially toxic dyes are introduced mainly to rivers through industrial effluents which have a high risk to human health and aquatic life. Activated carbon (AC) from the stem of Salvadora persica was synthesised to take off toxic industrial dyes from an aqueous solution. KOH was used as the activating agent throughout the preparation process for the AC. The morphology and composition of the prepared AC were studied by various analytical methods. From the overall results, it was found that the prepared AC is highly porous and thermal stability gained around 800 ℃. At room temperature, remediation of the dyes (cationic dye, methyl red and anionic dye, methylene blue) using the adsorption method was carried out to ascertain the impact of time and the quantity of AC on methylene blue (MB) and methyl red (MR) removal. During the initial 60min, equilibrium was attained for the optimum dye concentration (200mg/L). The data for adsorption on the AC obtained at equilibrium were examined by the Langmuir and Freundlich isothermmodels. Both the isotherms accurately predicted the data, with regression values of 0.99 for MR and 0.90 for MB, respectively. The equilibrium adsorption data was also analysed by kinetic models. The adsorption data well fittedin2nd order kinetic model. The results of MB and MR adsorption from solutions have demonstrated that the stem of Salvadora persica is one of the cheap and more eco-friendly options for remediation of toxic dyes from aqueous solutions.

Investigation of Eucalyptus camaldulensis and Tamarix aphylla species' capacities for methylene blue removal in wastewater and heavy metal remediation in soil.

In the contemporary landscape, the reuse of wastewater holds paramount significance. Concurrently, wastewater carries an array of pollutants encompassing chemical dyes and heavy metals. This study delves into the potential of Tamarix aphylla (TA) and Eucalyptus camaldulensis (EC) species for mitigating heavy metals in soil and eliminating methylene blue dye (MB) from wastewater. The research begins with assessing the dye adsorption process, considering pivotal factors such as initial pH, adsorbent dosage, initial dye concentration, and contact time. Outcomes reveal EC's superiority in dye removal compared to TA. As a bioremediation agent, EC exhibits a 90.46% removal efficacy for MB within 15 min, with pH 7.0 as the operative condition. Equilibrium analysis employs Temkin (T), Freundlich (F), and Langmuir (L) isotherms, revealing an excellent fit with the L isotherm model. The study delves further by probing surface adsorption kinetics through pseudo-first-order (PFO) and pseudo-second-order (PSO) models. Furthermore, to discern the divergent impacts of EC and TA on soil heavy metal reduction, soil samples were collected from three distinct zones: an untouched control area, alongside areas where EC and TA were cultivated at the Yazd wastewater site in Iran. Heavy metal levels in the soil were meticulously assessed through rigorous measurement and statistical scrutiny. The findings spotlight TA-cultivated soil as having the highest levels across all examined factors. Ultimately, EC emerges as the superior contender, proficiently excelling in both MB eliminations from wastewater and heavy metal amelioration in the soil, positioning it as the preferred phytoremediation agent.