Removal Of Malachite Green Dye Research Articles

Effect of Ni doping on the adsorption and visible light photocatalytic activity of ZnO hexagonal nanorods

Pristine and 1, 1.5, 2, 2.5 and 3 wt% Ni doped ZnO nanorods are prepared by hydrothermal technique as an effective photocatalyst for the removal of Malachite Green (MG) dye from aqueous media. Kinetic modelling of photocatalytic degradation and adsorption properties of the catalysts are done by pseudo first order (PFO), pseudo second order (PSO), fractal like psuedo first order (FPFO), fractal like psuedo second order (FPSO), elovich, exponential and intra particle diffusion (IPD) models. In contrary to the general trend, adsorption efficiency of ZnO is decreased while photocatalytic property got enhanced with doping. As-prepared catalysts are well characterised using XRD, FESEM, XPS, EDS, BET, UV and PL. This study points out the effect of Ni doping on the adsorption and visible light photocatalytic properties of ZnO nanostrutures via detailed kinetic modelling and explanation through various characterisation techniques and show cases their practical application in the field of waste water management. Water quality analysis was done post to degradation studies and the purified water samples have pH in the permissible range of drinking water which shows the efficient removal of dye molecules from the solution.

Removal of Malachite Green Dye from Aqueous Solution by Catalytic Wet Oxidation Technique Using Ni/Kaolin as Catalyst.

In this study, natural Algerian kaolin was used as a support and impregnated with nickel at different loading amounts (2 wt.%, 5 wt.%, and 7 wt.%) in order to prepare a supported catalyst. The wet impregnation technique was used in this preparation; nickel oxide (NiO) was the active phase precursor of the catalyst, and the catalysts were designated as follows: 2%, 5%, and 7% Ni/kaolin. These catalysts were put to the test in catalytic wet peroxide oxidation (CWPO) for degrading the organic contaminant malachite green dye (MG). Analytical techniques such as FTIR spectroscopy, X-ray diffraction, BET, and X-fluorescence were used to examine the structure, morphology, and chemical composition of the support and the produced catalysts. Several parameters, including temperature, catalytic dose, metal loading, hydrogen peroxide volume, and kinetic model were systematically investigated. The combination of improved parameters resulted in a significant increase in the catalytic activity, achieving a high removal rate of MG dye of 98.87%.

Tailoring of 2D MoS2 microspheres on 3D low-cost DE for the efficient removal of hazardous cationic dyes

The primary challenge involved in the water treatment field is to treat/clean the contaminated waste dye solutions before it releases into the environment. Industrial contaminant such as dyes are released into water streams, rendering the water unfit for further use. Treatment of such dye contaminants is still a challenging tasks that has evolved as one of the leading issues in environmental remediation. Some of the significant limitations in dye adsorption include time-consuming, synthetic routes, expensive adsorbents, more contact time, less adsorption performances and use of more adsorbents. To address such problems, herein in this work, 2D MoS2 molybdenum disulfide)-3D DE (diatomaceous earth) hybrid materials were synthesized by a facile and efficient hydrothermal route. The prepared innovative combination of 2D & 3D porous hybrid materials demonstrated to be efficient adsorbents for the efficient removal of malachite green (MG) dye from aqueous solution with superior 97 % removal efficiency within 5 mins and with an extended 60 mins of contact time possible to achieve 99.9 % of removal efficiency. Furthermore, the maximum adsorption capacity for DE was only 0.78 mg/g and developed 2D MoS2-3D DE exhibited an outstanding 110 mg/g for MB dye which is a significant improvement when compared to pristine DE. On the other hand, the 2D MoS2-3D DE was explored as a membrane-based filter for the removal of other important cationic pollutant methylene blue (MB) dye which showed 100 % rejection for varied MB volumes from 50 to 200 mL with average flux rate of 2200 L.m−2.h−1. Additionally, the 2D-3D hybrid adsorbents substantiated with better recyclability with up to 5 cycle performances which could be an excellent candidate for the removal of industrially important cationic dyes in the future.

A novel bionanocomposite from doped lipase enzyme into magnetic graphene oxide-immobilized-cellulose for efficient removal of methylene blue and malachite green dyes

Immobilized biosorbents with enzymes have become a topic of interest in the fields of environmental and energy science owing to their numerous advantages such as ease of separation, non-toxicity, biocompatiblity, high activity, and regeneration capability for further reuse. In this respect, lipase fromCandida rugose was selected to covalently immobilize ontoa supporting matrix of magnetic graphene oxide-immobilized-cellulose via glutaraldehyde to produce a magnetic bionanocomposite (MGO@Cellulose@Lipase) for the effective removal of methylene blue (MB) and malachite green (MG) from water as two target cationic pollutants. The as-synthesized bionanocomposite was characterized by various techniques to confirm the structure composition, surface morphology, thermal and magnetic properties. The SEM and HR-TEM examinations referred to good homogeneity and surface porosity with 23.80–32.69 nm as the identified particle size. Based on the BET analysis, MGO@Cellulose@Lipase exhibited a mesoporous structure with a mean pore size 11.56 nm, while the VSM results showed that the prepared bionanocomposite particles exhibited a saturation magnetization value 14.78 emu/g. To evaluate the adsorption performance of the newly designed bionanocomposite, batch adsorption experiments was carried out, under the influence and impact of various experimental controlling parameters. The adsorption correlations of MB and MG pollutants were fitted to Langmuir isotherm and pseudo-second order kinetics. The maximum computed adsorption capacity (qmax) for MB and MG were 66.79 and 51.87 mg/g, respectively. Thermodynamic studies confirmed the spontaneity and the endothermic nature of the adsorption process. Moreover, excellent removal efficiency of MB and MG by MGO@Cellulose@Lipase after five consecutive adsorption–desorption cycles were confirmed as 97.43% and 87.60%, respectively. The validity and applicability of MGO@Cellulose@Lipase in removal of MB and MG pollutants from real water samples were characterized in the range 95.09–96.24% and 91.01–92.58%, respectively. Therefore, the outlined results prove that the MGO@Cellulose could be used as a promising carrier alternative for enzymes immobilization and the assembled MGO@Cellulose@Lipase bionanocomposite was also characterized as an innovative green material for solving the environmental dye pollution.

Thiol‐yne 3D Printable Polymeric Resins for the Efficient Removal of a Model Pollutant from Waters

AbstractA new 3D printable resin formulation is developed and optimized from commercially available thiol (pentaerythritol tetrakis(3‐mercaptopropionate); PETMP) and alkyne (3‐butyn‐1‐ol; BA) monomers. Printed objects are characterized by Fourier‐transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The extraction efficiency of the printed thiol‐yne device is then investigated using a model dye – malachite green (MG). The results displayed excellent dye removal efficiency with > 95% MG removed within 5 min. The 3D‐printed devices are reusable and show 100% removal over six cycles after washing with deionized water and methanol. The presence of surface hydroxyl groups derived from the BA monomer is shown to enhance dye adsorption in comparison to control materials. The printing procedure and resin formulation are robust and consistent when devices from different resin batches are compared for MG dye removal. The thiol‐yne 3D printed devices demonstrated excellent dye removal (> 99%) from water samples collected from a tap and a nearby river source. The successful development of this resin provides a new thiol‐yne‐based resin system for stereolithography (SLA) 3D printing for the removal of organic dyes from wastewater and presents a potential for broad applications in water treatment.

Statistically optimized sequential hydrothermal route for FeTiO3 surface modification: evaluation of hazardous cationic dyes adsorptive removal.

In the present study, the performance of facile hybrid sequential chemical treatments of titanomagnetite concentrate (TC), alkaline leaching, and sodium dodecyl sulfate (SDS) modification has been evaluated for the removal of crystal violet (CV), malachite green (MG), and methylene blue (MB) cationic dyes. The physical and chemical properties of samples were characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), N2 adsorption-desorption, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and Fourier transform infrared spectroscopy (FTIR) analyses. Moreover, dye removal in the batch system was investigated by evaluating adsorbent dosage, contact time, initial dye concentration, pH of the solution, temperature, electrolyte concentration, adsorption isotherm, kinetic, and thermodynamic. The results showed that the maximum adsorption capacity was obtained at SDS concentration of 6mM, NaOH concentration of 9M, the temperature of 160°C, solid/liquid ratio of 4g/100mL, and the process duration of 24h. In the alkaline leaching process, forming the Na2TiO3 phase with sharp and high energy points can be improved the adsorption properties. Accordingly, the adsorption capacity and removal efficiency attained 19.84, 18.64, and 19.66mg/g and 99.21, 93.24, and 98.31% for CV, MG, and MB, respectively. Furthermore, the dye removal followed pseudo-second-order (R2 = 0.9990) and Freundlich (R2 = 0.9970) models. The evaluation of thermodynamic parameters indicated the endothermic (∆H° = 110.91J/mol) and spontaneous nature (ΔG˚ < 0) of the adsorption process. This study concluded that the modified TC had a potential ability for application in textile wastewater treatment.

Photocatalytic and antimicrobial activities of pure and Mn doped ZnO nanoparticles synthesised by Annona Muricata leaf extract

ABSTRACT The present work aim to investigate the photocatalytic, antibacterial and antifungal activities of Zn1-xMnxO (x = 0.0, 0.03, 0.05 and 0.07) nanoparticles synthesised using the leaf extract of Annona Muricata via green synthesis method. The effect of Mn doping in the obtained nanopowder were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM), selected area diffraction pattern (SAED), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and UV-visible spectroscopy techniques. XRD pattern confirms hexagonal wurtzite structure of ZnO nanoparticles. Incorporation of Mn into the ZnO host lattice was confirmed by XPS measurement. Morphology of nanoparticles shows irregular, spherical shapes with agglomeration. Presence of Zn, Mn and O elements in the EDAX reveals the perfect nature of nanostructures. The synthesised pure and Mn-doped ZnO nanoparticles were found to be significant antibacterial activity against gram positive Bacillus subtilis, Staphylococcus aureus and gram negative Pseudomonas aeruginosa bacterial pathogens as well as the fungal strain of Candida albicans and Aspergillus Niger. The minimum zone of inhibition observed for bacterial and fungal pathogens confirms better antimicrobial activity of ZnO nanoparticles. The Mn-doped nanoparticle shows comparatively enhanced removal of methylene blue (MB), malachite green (MG) and Congo red (CR) dye under sunlight. These results indicates the green synthesised pure and Mn-doped ZnO nanoparticles have valuable applications in environmental and biomedical fields.

Application of emulsion liquid membrane for removal of malachite green dye from aqueous solution: Extraction and stability studies

Malachite green (MG) dye has various applications as a dyeing material, medical disinfectant and biocide but is also recognized as a teratogenic, carcinogenic, mutagenic and respiratory toxic material which creates dire effects on human beings, aquatic flora and fauna. Hence, the main objective lies in the removal of MG dye from an aqueous stream. In the current investigation, emulsion liquid membrane (ELM) technique was used and the effect of different factors like concentration of carrier, surfactant, stripping phase and its type and volume ratio of membrane to stripping solution on the removal of MG dye were studied. MG extraction efficiency of 94.99% was achieved using emulsion consisting of 2% w/v Span 80, 2% w/v D2EHPA, 0.1 N HCl and membrane phase to stripping phase volume ratio 1. Microscopic studies of the emulsion revealed the formation of well-defined and large number of globules with very less coalescence which resulted in high removal of MG dye. The physical stability of the emulsion was analysed and the phase separation was comparatively less at various time intervals suggesting that the conditions used for preparing the emulsions are suitable. Fourier transform infrared spectroscopy established the bonding and presence of various functional groups. The current study intends to fulfill the gap by exploring the removal of MG dye by ELM technique.

Utilization of fly ash for the effective removal of hazardous dyes from textile effluent

• Fly Ash from brick kiln was modified as Brick Sand Blended Fly Ash for the dye adsorption. • BSBFA fly ash was used for the removal of Malachite Green and MV dyes. • Maximum removal efficiency for MV was recorded up to 96% by using BSBFA. • The system follows Langmuir and first order Lagregren in isotherm and kinetics model. A novel adsorbent, Brick Sand Blended Fly Ash (BSBFA) from Brick Kiln, removes synthetic dyes from the polluted aqua. It is a cost-effective and environmentally suitable material. This study compares the adsorption capacity of BSBFA when used to treat Malachite Green (MG) and Methyl Violet (MV) dye as synthetic pollutants. Characterization studies like Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and Fourier Transform Infrared Spectroscopy (FTIR) are performed to evaluate the surface area, available active sites, and functional groups in BSBFA. Batch study experiments like adsorbent dose, pH, initial dye concentration, contact time, and temperature are varied to attain good removal efficiency. The adsorption capacities of MV and MG are 5.144 mg/g, and 5.88 mg/g is achieved through the batch mode process. The adsorption process was examined by the Lagergren first-order model, Natarajan and Khalaf model, Bhattacharya and Venkobhachar, and intraparticle diffusion models to state the adsorption mechanism. The interaction between the adsorbent and the adsorbate can be determined by Langmuir and Freundlich isotherms. The isotherms are used to evaluate the homogeneous and heterogeneous nature of the adsorption process. MG has a higher adsorption capacity than MV, and it states that BSBFA is a sustainable adsorbent and can be used as a dye removing agent.

Simultaneous removal of cationic and anionic dyes from simulated industrial effluents using a nature-inspired adsorbent

Alginate-grafted polyaniline (Alg-g-PANI) microparticles were synthesized through the grafting of aniline onto functionalized Alg followed by double crosslinking by glutaraldehyde and calcium chloride. The performance of the developed microparticles as adsorbent in simultaneous removal of malachite green (MG) and congo red (CR) dyes were examined by the batch method. Experimental parameters, including adsorbent amount, pH, initial dyes concentrations, and contact time were optimized. Langmuir and Freundlich adsorption models were employed to explore the equilibrium isotherm. As the Langmuir model results, the maximum adsorption capacities (Qm) of microparticles for the MG and CR dyes were obtained as 578.3 and 409.6 mgg−1, respectively. Adsorption kinetics for both dyes were well-fitted with the pseudo-second-order model that confirm the rate-limiting step might be the chemical adsorption. The adsorbent was regenerated via desorption process and was reusable five times without a substantial decrease in its adsorption efficacy in first three cycles. Adsorbent-dyes interactions were computationally evaluated using Gromacs package, and it was found that both MG and CR are able to interact strongly with the adsorbent. In accordance with experimental results, simulation data revealed that MG can be removed more efficiently than those of the CR. As the experimental results, we could conclude that the synthesized Alg-g-PANI microparticles can be used as a nature-inspired adsorbent for simultaneous removals of CR and MG dyes.

Development of Antifouling Thin-Film Composite/Nanocomposite Membranes for Removal of Phosphate and Malachite Green Dye.

Nowadays polymer-based thin film nanocomposite (TFN) membrane technologies are showing key interest to improve the separation properties. TFN membranes are well known in diverse fields but developing highly improved TFN membranes for the removal of low concentration solutions is the main challenge for the researchers. Application of functional nanomaterials, incorporated in TFN membranes provides better performance as permeance and selectivity. The polymer membrane-based separation process plays an important role in the chemical industry for the isolation of products and recovery of different important types of reactants. Due to the reduction in investment, less operating costs and safety issues membrane methods are mainly used for the separation process. Membranes do good separation of dyes and ions, yet their separation efficiency is challenged when the impurity is in low concentration. Herewith, we have developed, UiO-66-NH2 incorporated TFN membranes through interfacial polymerization between piperazine (PIP) and trimesoyl chloride (TMC) for separating malachite green dye and phosphate from water in their low concentration. A comparative study between thin-film composite (TFC) and TFN has been carried out to comprehend the benefit of loading nanoparticles. To provide mechanical strength to the polyamide layer ultra-porous polysulfone support was made through phase inversion. As a result, outstanding separation values of malachite green (MG) 91.90 ± 3% rejection with 13.32 ± 0.6 Lm−2h−1 flux and phosphate 78.36 ± 3% rejection with 22.22 ± 1.1 Lm−2h−1 flux by TFN membrane were obtained. The antifouling tendency of the membranes was examined by using bovine serum albumin (BSA)-mixed feed and deionized water, the study showed a good ~84% antifouling tendency of TFN membrane with a small ~14% irreversible fouling. Membrane’s antibacterial test against E. coli. and S. aureus. also revealed that the TFN membrane possesses antibacterial activity as well. We believe that the present work is an approach to obtaining good results from the membranes under tricky conditions.

Efficient removal of Rose Bengal and Malachite Green dyes using Green and sustainable Chitosan/CMC/Bentonite-based hydrogel materials

Efficient removal of Rose Bengal and Malachite Green dyes using Green and sustainable Chitosan/CMC/Bentonite-based hydrogel materials

Characterization and adsorption of malachite green dye from aqueous solution onto Salix alba L. (Willow tree) leaves powder and its respective biochar

In the present study, the use of low-cost, highly efficient, eco-friendly, and abundantly available (in Kashmir region, J&K India) willow leaves from which adsorbents like willow leaves powder (WLP) and willow leaves biochar (WLB) were prepared, have been found to be efficient for malachite green (MG) dye removal and can be used as an alternative to the current expensive methods of removing the same dye from an aqueous solution. The techniques like Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and carbon, hydrogen, nitrogen, sulphur (CHNS) analyser were used to characterize the samples without any chemical treatment. SEM of the adsorbents shows the presence of different sized pores, cracks, and crevices. FTIR and CHNS show functional groups and elemental concentration, respectively. The effects of various experimental parameters such as contact time, adsorbent dosage, initial dye concentration, salt treatment, and pH were investigated and optimal experimental conditions were obtained. It has been found that Langmuir, Freundlich, and Temkin isotherms were useful for describing the equilibrium of adsorption system. The equilibrium adsorption data in this research work was found to follow both Langmuir and Freundlich isotherm models and maximum monolayer capacity of WLP and WLB were found to be 10.014 and 21.244 mg/g, respectively. The experimental data for both WLP and WLB followed pseudo-second-order kinetic model with R2= 0.999. Intraparticle diffusion model reveals that more than one mechanism influenced the adsorption process. Thermodynamic study concluded that the adsorption is spontaneous for both adsorbents but exothermic for WLP and is endothermic in nature for WLB. Present exploration and comparison with other reported adsorbents concluded that, WLP and WLB may be useful as low-cost attractive option for the removal of MG dye from aqueous solution and therefore, also from wastewater containing MG dye.

Green synthesis of Mn3O4 nanoparticles using Costus woodsonii flowers extract for effective removal of malachite green dye

The pollution of organic dyes such as malachite green is one of the globally critical issues, calling for efficient mitigation methods. Herein, we developed green Mn3O4 nanoparticles synthesized using natural compounds extracted from Costus woodsonii flowers under an ultrasound-assisted mode. The materials were characterized using several physicochemical techniques such as Fourier-transform infrared spectroscopy, X-ray diffraction, Energy-dispersive X-ray spectroscopy, scanning electron microscopy, Raman spectroscopy, and N2 adsorption desorption isotherm measurement. The X-ray diffraction and N2 isotherm plots confirmed the presence of tetragonal γ-Mn3O4 phase and mesoporous structure, respectively. Carbonyl groups derived from flavonoids or carboxylic compounds were found in the surface of green Mn3O4 nanoparticles. The effect of pH, contact time, dose, and concentration on the adsorption of malachite green over green Mn3O4 was carried out. The maximum malachite green adsorption capacity for green Mn3O4 nanoparticles was 101–162 mg g−1. Moreover, kinetic and isotherm adsorption of malachite green obeyed Langmuir (Radj.2 = 0.980–0.995) and pseudo first-order models (Radj.2 = 0.996–1.00), respectively. Adsorption of malachite green over green Mn3O4 was a thermodynamically spontaneous process due to negative Gibbs free energy values (ΔGο < 0). Green Mn3O4 nanoparticles offered a high stability through the FR-IR spectra analysis. With a good recyclability of 4 cycles, green Mn3O4 nanoparticles can be used as potential adsorbent for removing malachite green dye from water.

Porous graphitic carbon nitride nanosheets coated with polyfluorene for removal of Malachite green and Methylene blue dyes and Cu (II) ions

Dyes and heavy metal ions are of great interest for environmental studies as they are common pollutants in industrial applications. Therefore, development of innovative adsorbents has received tremendous interest in wastewater treatment studies. In this study, a new hybrid adsorbent (g-C3N4/AFP) was prepared by modifying porous graphitic carbon nitride surface (g-C3N4) with 2-amino fluorene polymer (AFP) and investigated its adsorptive behaviour for removal of representative dyes and heavy metal from aqueous solution. Experimental data obtained from batch tests were analysed using two parameters (Freundlich, Langmuir and Dubinin–Radushkevich) and three parameters (Sips) isotherm models. Langmuir isotherms were the best model to describe the experimental results of Methylene blue (MB) and Malachite green (MG) dye adsorptions, while Freundlich isotherms were the best for Cu (II) ions. Sips isotherm model was found to have the highest regression coefficient (≥0.99) among the two-parameters isotherms studied. The maximum adsorption capacities of g-C3N4 and g-C3N4/AFP were found to be 226.88 and 327.83 for MG, 85.73 and 221.85 for MB and 184.51 and 452.19 mg g−1 for Cu (II), respectively. This increase in adsorption capacity can be explained by the improved textural properties of the new hybrid adsorbent and the presence of multiple functional groups in its structure. A possible adsorption mechanism was suggested using FTIR and pHpzc data.

ZnO/POA functionalized metal-organic framework ZIF-8 nanomaterial for dye removal

In this work, a novel metal-organic framework ZIF-8 is fabricated with poly-o-anisidine/zinc oxide (POA/ZnO) to obtain poly-o-anisidine/zinc-oxide nanohybrid material (PAZ@ZIF-8) via in-situ approach at room temperature. The characteristics of as-prepared nanocomposites were investigated by employing sophisticated techniques such as SEM, TEM, FTIR, XRD, and SEM-EDAX. The PAZ@ZIF-8 nanohybrid material exhibits a significant rational function for the adsorption of highly toxic organic pollutants. The as-synthesized nanohybrid materials are employed to remove Malachite Green (MG) dye from aqueous solutions. PAZ@ZIF-8 has displayed excellent removal efficiency towards the removal of MG dye, and almost 96% of the dye is removed within a very short period as compared to ZIF-8 (34%) and POA/ZnO (61%), respectively. The experiments were carried out at different pH values (3 - 9) and adsorbent amounts (1 - 1.5 mg/g). The Langmuir sorption model is a better fit for the removal of MG dye on PAZ@ZIF-8, and the maximum adsorption capacity of 613 mg/g is observed. The sorption kinetics of MG dye on PAZ@ZIF-8 is well followed by the pseudo-second-order model. PAZ@ZIF-8 has shown excellent recyclability for three consecutive cycles, and almost 90% of the dye is removed in the third cycle. This research will overlay the road to developing innovative nanohybrid 3D-MOF adsorbent systems for detoxification and wastewater treatment.

Removal of Malachite Green Dye from Wastewater Using Natural and Activated Siirt/Koçpınar Clay

Bu araştırmada, genellikle akvaryumculukta, sıklıkla da pamuk ve elyaf gibi ürünlerin boyanmasında kullanılan toksik ve kanserojen bir boyar madde olan malahit yeşilinin atık sulardan Siirt/Koçpınar kili kullanılarak uzaklaştırılması incelenmiştir. Çalışmamızın ilk aşamasında adsorbent herhangi bir modifiyeye maruz bırakılmadan (K1) gerekli çalışmalarda kullanılmış, ardından aynı işlemler nitrik asit ile modifiye edilen adsorbent (K2) ile tekrar edilmiştir. Çalışmada başlangıç pH’ının (2.0 – 8.0 aralığı), adsorbent miktarının (0.05 g - 1 g aralığı), derişimin (50 ppm - 150 ppm aralığı), sıcaklığın (298 K - 323 K aralığı) ve temas süresinin (0 dk. - 120 dk. aralığı) etkinliği de araştırılmış ve elde edilen veriler Langmuir, Freundlich, D-R izoterm modellerine uygulanmıştır. Çalışma sonucunda en iyi verim pH 5 başlangıç değeri ile 0.2 g adsorbent kullanılarak yapılan çalışmalarda elde edilmiş ve çalışma neticesinde de K1 adsorbenti için %63.05, K2 adsorbentin de %91.99 giderim sağlanmıştır. İzoterm hesaplamaları sonucunda Freundlich izoterm modeline ait korelasyon katsayısı tüm sıcaklıklarda 0.98’den büyük bulunmuştur. D-R izoterm modeli yardımıyla hesaplanan D-R adsorpsiyon serbest enerjisi ise her iki kil ve tüm sıcaklıklar için 8 kJ/mol değerinden küçük bulunmuştur. Termodinamik hesaplamalar yardımıyla bulunan Gibbs serbest enerji değerlerinin negatif olması, adsorpsiyon işleminin kendiliğinden meydana geldiğini göstermiştir.

Ultrahigh adsorption by regenerable iron-cobalt core-shell nanospheres and their synergetic effect on nanohybrid membranes for removal of malachite green dye

The accelerated use of an industrial dye (malachite green (MG)) has led to serious deterioration of water bodies. Although, several water treatment methods have been investigated for MG removal, but they are either costly or produce several byproducts. To address these issues, the present research demonstrates the application of reusable iron-cobalt (Fe-Co) core-shell nanospheres against MG removal from water, using batch adsorption and membrane filtration technique. During batch adsorption, almost complete MG removal (99.8%) was observed against significantly high dye concentration (150 ppm) and the maximum adsorption capacity achieved was 270.27 mg g−1. Furthermore, the adsorbent exhibited excellent reusability up to five consecutive cycles. For membrane filtration studies, remarkable MG dye removal efficiency (97%) was achieved through M-0.1 membrane (containing 0.1% Fe-Co loading) along with outstanding water flux rate (214.73 L/m2 h). Additionally, a multi-cycle filtration test for M-0.1 membrane demonstrated high stability in MG dye separation performance and permeate flux throughout three consecutive cycles. All findings confirm the outstanding potential and financial feasibility of Fe-Co nanospheres in the removal of MG dye for both batch adsorption as well as membrane filtration processes.

Removal of Malachite Green Dye from Water Using MXene (Ti3C2) Nanosheets

In the present study, new emerging 2D Mxene nanosheets (MXNSs) were synthesized from MAX phase powders of Ti3AlC2 and then characterized using a scanning electron microscope (SEM) and X-ray diffraction (XRD) to explore the chemical and physical properties of the prepared MXNS. The characterization of the synthesized MXNS indicated the formation of exfoliated 2D MXene nanosheets (Ti3C2) as a result of the HF treatment of the MAX phase, which was confirmed by XRD measurements, as the characteristic peaks of 2D MXene nanosheets were only observed. The synthesized MXNS was then used as a solid adsorbent for removing malachite green dye (MG) from water. The effects of different operational factors such as MXNS dose, solution temperature, time, MG concentration, solution pH, and ionic strength have also been evaluated. The adsorption results showed that the temperature of the solution, as well as its pH, significantly influenced MG removal when using MXNS. The optimum removal was obtained within 150 min, with 20 mg of MXNS at ambient temperature and a pH value of 6.0. The maximum removal capacity obtained was 4.6 mg MG per g of MXNS using 5 mg of MXNS with a removal efficacy of 46.0%, and the minimum removal capacity obtained was 2.5 mg MG per g of MXNS using 20 mg of MXNS with a removal efficacy of 99.1%. Finally, the results displayed that the MXNS solid adsorbent was able to absorb a high percentage of MG and maintained reasonable efficiency for four consecutive cycles, indicating that MXNS could be a promising adsorbent in wastewater remediation and environmental sustainability.

Selective and effective adsorption of malachite green and methylene blue on a non-toxic, biodegradable, and reusable fenugreek galactomannan gum coupled MnO2 mesoporous hydrogel

A new FG-g-AM-cl-MBA-MnO2 hydrogel has been synthesised via a free radical cross-linking reaction using fenugreek gum containing macromolecular galactomannan units, acrylamide, N, N′-methylenebisacrylamide, potassium persulfate, and MnO2 for removal of methylene blue and malachite green dyes from water. Surface morphology of synthesised hydrogel was porous and rough as determined by FESEM. The presence of functional groups and cross-linking mechanism were validated by FTIR spectroscopy. TGA revealed that FG-g-AM-cl-MBA-MnO2 hydrogel is thermally stable up to 700 °C and mass ratio of MnO2 was found to be 25.9%. BET technique gave surface area as 5.59 m2/g with a pore radius of 3.654 nm. The swelling ratio of FG-g-AM-cl-MBA-MnO2 hydrogel was 1862% at 313 K. To evaluate the influence of adsorbent dose, contact time, temperature, pH, and dye concentration on adsorption behaviour of hydrogel several batch experiments were conducted. The hydrogel preferentially removes MG (98.5%) and MB (96.3%) effectively following Langmuir model with 526.31 and 483.09 mg/g adsorption capacity, respectively. The adsorption process followed pseudo-second-order kinetics and thermodynamics study revealed that process is endothermic and spontaneous. The hydrogel retained more than 85% adsorption capacity even after ten cycles of dye adsorption-desorption process and thus, serves as a proficient, reusable, and eco-friendly adsorbent for wastewater remediation.