Adsorption Process Of Ions Research Articles

A review of the application of fungi as an effective and attractive bio-adsorbent for biosorption of heavy metals from wastewater.

One of the most hazardous environmental pollutants is the pollution risen by heavy metal ions in effluents, which is increasing due to the increasing human activity and the development of urbanization. Notwithstanding the economic challenges to control the pollution of effluent treatment processes, it seems necessary to provide effective approaches. The sorption method is widely used due to low-cost, flexibility in design and operation, repeatability, and significant performance. Hence, the need for more environmentally friendly sorbents to eliminate metal ions is greater than ever. Due to the unique features such as the presence of chitin and chitosan in the cell wall, high absorption capacity, environmental friendliness, availability, and cheapness, the use of fungi as adsorbent has received much attention. Therefore, this work tries to address the use of fungi as biosorbents to remove these metals, the dangers of heavy metals, and their sources. Moreover, equilibrium, kinetic, and thermodynamic behaviors of the heavy metal ion adsorption process in the literature are briefly studied.

Insights into the Synergistic Removal of Copper(II), Cadmium(II), and Chromium(III) Ions Using Modified Chitosan Based on Schiff Bases-g-poly(acrylonitrile).

Chitosan has received broad consideration as an adsorbent for all pollutants because of its low cost and great adsorption potential. However, its shortcomings, including sensitivity to pH, poor thermal stability, and poor mechanical strength, limit its use. The functional groups of chitosan can be modified to enhance its performance by the grafting technique and Schiff base modification. The grafting process used acrylonitrile (Ch-g-PAN) as a monomer and potassium persulfate as an initiator. After that, the modification via preparation of the Schiff base reaction using salicylaldehyde (Ch-g-Sch I) and P-anisaldehyde (Ch-g-Sch II) was carried out. The synthesized copolymers were detailed and characterized through several spectroscopic and microscopic techniques including infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. In addition, Ch-g-Sch I and Ch-g-Sch II were applied in the removal of different metal ions such as Cu2+, Cd2+, and Cr3+. The maximum adsorption capacity of Ch-g-Sch I for Cd2+ was 183.7 mg g-1 in 24 h, while in the case of Ch-g-Sch II, the maximum adsorption capacity for Cd2+ was improved to 322.9 mg g-1 for the same time. Moreover, adsorption thermodynamic analysis displays that the all ion adsorption process was not random and the pseudo-second-order model fitted with experimental results. Finally, Ch-g-Sch I and Ch-g-Sch II were applied as designs for industrial wastewater treatment with significant efficiency.

Uji Kemampuan Adsorpsi Komposit Keratin Bulu Itik-Polietilena Terhadap Ion Besi(III)

Research on the adsorption of iron(III) ion using an adsorbent from duck feather-polyethylene composite has been studied. This study aimed to determine the optimum pH conditions and the optimum contact time required in the iron(III) ion adsorption process. Optimum pH and contact time are then measured using AAS to determine the amount of iron(III) ion adsorbed with the duck feather-polyethylene composite adsorbent. The determination of the optimum pH was carried out with pH variations which are 2, 3, 4, 5, 6, 7, and 8, while determination of the optimum contact time was carried out with contact time variations which are 40, 60, 80, 100, 120, 140, and 160 minutes. The result of this research showed that optimum conditions for iron(III) ion adsorption at pH 6 and contact time at 80 minutes, which each adsorption capacity are 68.33% and 79.78%.

Vibrational and impedance analysis of the β-stannic acid samples plasticized by perchloric acid

The β-stannic acid powders(I) containing various amounts of perchloric acid with an initial concentration of 56.2 wt% HClO4 were studied by IR and Raman spectroscopy combined with XRD analysis and impedance spectroscopy. The addition of aqueous perchloric acid to I at room temperature leads to the adsorption compound formation. The degree of ionization of HClO4 is 100%. Based on these studies, a structural model has been proposed, according to which the hydrated H+ and ClO4¯ ions fill the pores/capillaries of I. The structure of I does not change during the adsorption process of ions. The finely dispersed powder of I turns into a viscous transparent gel with an optimal ratio of reagents, which indicates its plasticization. The electrochemical properties of the plasticized samples were investigated by impedance method. It was found that plasticization can increase the proton conductivity by more than two orders of magnitude. The plasticized samples have sensory properties. The plot of conductivity σ¯25 versus weight fractions of perchloric acid solution Wpa reveals a linear dependence at RH = 32% and t = 25 °C in a wide range of Wpa values. The maximum value of σ¯25 = 0.43 S cm−1 is achieved at Wpa = 0.61. The straight line has a break at the very beginning due to the perchloric acid flow threshold.

Applicability of Green Absorbents to Remove Lead (II) from Polluted Water: a Potential Low-cost Adsorbent

The present work represent potential bio-sorbent (banana and pomegranate peel) in nano size range, with a view to for adsorption of lead(II) ions from aqueous solution. Dose, adsorbate concentration, pH, time, and temperature factors were investigated. The most favorable stipulations for Pb (II) adsorption are 50 mg /L as initial concentration, 0.2 g as pomegranate and banana peels mass and pH 5.5 and 5.23for banana and Pomegranate peel. Removal data obey the Langmuir model with qmax of 25.64 mg/g for banana and 41.66 mg/g for Pomegranate peel. The kinetics of removal process was fitted well by a second -order equation. It was observed that that the Pb (II) ion adsorption process on the both bio-sorbents is spontaneous process, endothermic for banana while exothermic for pomegranate peel. A distinct improvement in the adsorbent surface was noted after adsorption process which demonstrated via scanning electron microscope.

Characterizing and modeling of oak fruit shells biochar as an adsorbent for the removal of Cu, Cd, and Zn in single and in competitive systems

In this study, the oak fruit shells (OFS) were used to prepare a biochar (OFSBC) obtained by one-step pyrolysis process at 700 °C. The obtained adsorbent was characterized to evaluate physicochemical properties and tested for the adsorption of Cu2+, Cd2+, and Zn2+ in an aqueous solution. The results proved that the prepared adsorbent has a large specific surface area (SBET = 520 m2/g), a large number surface functional groups and a developed porosity. The adsorption equilibrium metal ions onto OFSBC was reached after 4 h of contact time with a removal efficiency 95.29 %, 94.63 %, 82.99 % for Cu2+, Zn2+, and Cd2+, respectively. The Avrami fractional order was the suitable model that describes the kinetic adsorption process of metal ions onto OFSBC. The Freundlich isotherm model fits the experimental data slightly better than other models in single systems. The maximum adsorption capacities of Langmuir that were obtained were in the following order 41.97 mg/g, 41.79 mg/g, and 27.00 mg/g for Cu2+, Cd2+, and Zn2+ ions, respectively. In binary systems the equilibrium adsorption of these ions onto OFSBC was found to be antagonistic in nature and is well described by the extended Freundlich model. The thermodynamic study revealed that the adsorption of these metals was spontaneous and endothermic in nature.The regeneration of the adsorbent was tested in 5 adsorption/desorption cycles, with a slight decrease from cycle 1 to cycle 5. The prepared adsorbent could serve as promising material to remove Cu2+, Cd2+ and Zn2+ effectively from wastewater.

Study on zinc ions binding to the individual casein fractions: αS1-, β- and κ-casein

The presented work is focused on the isotherm study on the Zn2+ ions binding to the individual casein fractions: αS1-, β- and κ-casein (αS1CN, βCN and κCN). The experimental isotherms were evaluated using Freundlich and Langmuir models. Subsequently, the stability of the obtained complexes in the respective Zn2+ ion concentrations (120, 350, 600 mg/L) was determined by carrying out zeta potential measurements. Capillary electrophoresis combined with inductively coupled plasma mass spectrometry (CE-ICP-MS) confirmed the occurring binding process. Additionally, physicochemical characteristics of the obtained metal-protein complexes was performed including scanning electron microscopy (SEM) in two modes (SE and Z-contrast) and the binding sites of caseins to Zn2+ ions were indicated using attenuated total reflectance infrared spectroscopy (FTIR-ATR) and Raman analysis as well as mass spectrometry technique (MALDI-TOF MS). Isothermal studies indicated a heterogeneously complex zinc ion adsorption process, and a stability study showed that the zeta potential is strongly related to the hydrophobicity, size and structure of the casein isoforms studied. Electron microscopy confirmed the modification of casein surfaces due to the addition of Zn2+ ions. Spectroscopic techniques indicated the interaction of zinc ions with polar amino acids of casein, such as glutamic acid (Glu) and aspartic acid (Asp), but also His, Cys. The influence of phosphate groups was also observed. Finally, the study culminated in a molecular docking study of the Zn2+ ion binding process, which confirmed the presence of the listed amino acids responsible for the binding process.

Adsorption and physicochemical release of iron ions in soils with different content of Calcium Carbonate and Calcium Sulfate

Three soils of different content of gypsum and lime were selected, the first soil (G1) and the second soil (G3), were obtained near the fields of the Faculty of Agriculture, Tikrit University. As for the third soil (G5), was taken from the AL- alam Village side east of Tikrit city to a depth of (0-10)cm. the proportions of gypsum were 5%, 15%, 25%, and the proportions of lime were 25%, 20%, and 10% for soils G1, G3, and G5, respectively. Ferrous sulfate was added as a source of iron ions added to the three soils in the following proportions (0,10,25,50,100,150,250,500,750) mg.L-1 The concepts of isotherm were tested by using the physicochemical Freundlich and Langmuir adsorption equations. The results of the study showed the success of both equations in describing of iron ion adsorption process for all three soils, because They achieve a high (R2) but Langmuir's equation showed a greater superiority due to its decreasing (SE). As it appears from the results of the study, the superiority of treatment (G1) over treatments (G3) and (G5) in the maximum adsorption values, binding energy, (PBCFe)(KG) and (Kd) for adsorption and release. As for the values of Labale iron, the lowest value was in treatment (G1)then it began to increase until it reached its value in treatment (G5). The (Δf) values for the three soils were positive, and that the highest value was in soil (G1), and starts declining to reach its value for soil (G5).

Thermodynamics of Charge Regulation during Ion Transport through Silica Nanochannels.

Ion-surface interactions can alter the properties of nanopores and dictate nanofluidic transport in engineered and biological systems central to the water-energy nexus. The ion adsorption process, known as "charge regulation", is ion-specific and is dependent on the extent of confinement when the electric double layers (EDLs) between two charged surfaces overlap. A fundamental understanding of the mechanisms behind charge regulation remains lacking. Herein, we study the thermodynamics of charge regulation reactions in 20 nm SiO2 channels via conductance measurements at various concentrations and temperatures. The effective activation energies (Ea) for ion conductance at low concentrations (strong EDL overlap) are ∼2-fold higher than at high concentrations (no EDL overlap) for the electrolytes studied here: LiCl, NaCl, KCl, and CsCl. We find that Ea values measured at high concentrations result from the temperature dependence of viscosity and its influence on ion mobility, whereas Ea values measured at low concentrations result from the combined effects of ion mobility and the enthalpy of cation adsorption to the charged surface. Notably, the Ea for surface reactions increases from 7.03 kJ mol-1 for NaCl to 16.72 ± 0.48 kJ mol-1 for KCl, corresponding to a difference in surface charge of -8.2 to -0.8 mC m-2, respectively. We construct a charge regulation model to rationalize the cation-specific charge regulation behavior based on an adsorption equilibrium. Our findings show that temperature- and concentration-dependent conductance measurements can help indirectly probe the ion-surface interactions that govern transport and colloidal interactions at the nanoscale─representing a critical step forward in our understanding of charge regulation and adsorption phenomena under nanoconfinement.

Adsorption of Pb(II) ions from aqueous solutions by magnetite (Fe3O4) nanoparticles functionalized with two different Schiff base ligands

In this study, Fe3O4 magnetic nanoparticles were synthesized using a co-precipitation method and thereby modified with 3-aminopropyltriethoxy-silane (APTES) as the amine precursor, and 4- bromobenzaldehyde (BA) and 2-Formyl-1H-pyrrole (FP) as aldehyde precursors, to create Schiff ligands on the surface. In addition, FT-IR, FE-SEM, TGA-DTG, TEM, and XRD analyses were employed to characterize the nanoparticles. The resultant modified nanoparticles (Fe3O4-BA and Fe3O4-FP) were then applied for Pb(II) removal from aqueous solutions. The kinetic behavior of Pb(II) removal was studied through pseudo-first-order and pseudo-second-order adsorption experiments, resulting in the rate constants. According to the findings, the metal adsorption process followed a pseudo-second-order kinetic reaction. Assessing the equilibrium behavior of the adsorption process through Langmuir and Freundlich models revealed that the adsorption equilibrium data for Pb(II) ions on Fe3O4-BA and Fe3O4-FP followed the Langmuir and Freundlich isotherm models, respectively. Moreover, the results showed that the adsorption process of metal ions by the Fe3O4-BA and Fe3O-FP nanoparticles was affected by operating parameters such as pH, temperature, metal ion concentration and mass of adsorbent.

Preparation and Characterization of an Electrospun Whey Protein/Polycaprolactone Nanofiber Membrane for Chromium Removal from Water.

Chromium pollution represents a worldwide concern due to its high toxicity and bioaccumulation in organisms and ecosystems. An interesting material to remove metal ions from water is a whey-protein-based material elaborated by electrospinning, which is an emerging method to produce adsorbent membranes with diverse applications. The aim of this study was to prepare an adsorbent membrane of whey protein isolate (WPI) and polycaprolactone (PCL) by electrospinning to remove chromium ions from water. The adsorbent membrane was synthesized by a central composed design denaturing WPI using 2-Mercaptoethanol and mixing it with PCL to produce electrospun nanofibers. The adsorbent membrane was characterized by denaturation, Scanning Electron Microscope, Fourier-Transform Infrared Spectroscopy, Contact Angle, Thermogravimetric Analysis, and X-ray Photoelectron Spectrometry. The adsorption properties of this membrane were assessed in the removal of chromium. The removal performance of the membrane was enhanced by an increase in temperature showing an endothermic adsorption process. The adsorption process of chromium ions onto the nanofiber membrane followed the Sips adsorption isotherm, while the adsorption kinetics followed a pseudo-second kinetics where the maximum adsorption capacity was 31.0 mg/g at 30 °C and pH 2. This work provides a novel method to fabricate a hybrid membrane with amyloid-type fibrils of WPI and PCL, which is a promising adsorbent to remove heavy metal ions from water.

Integrated Process of Ammonium Ion Adsorption by Natural Dispersed Sorbents

The process of adsorption treatment of effluents from ammonium ions is considered as an integrated two-stage process consisting of the stage of adsorption of contaminants by natural sorbents in the apparatus with a stirrer and the liquid separation stage and solid phases. Mathematical models of ammonium ions adsorption from effluents by natural dispersed sorbents are proposed, based on the assumption that the process is described by Langmuir and Friendlich isotherms. The values of ion exchange equilibrium constants for different types of natural sorbents have been established by identifying experimental data for theoretical dependences. The obtained constants can be used to calculate the average concentration of ammonium ions in the solution and in the grain of the sorbent in the process of integrated adsorption process. Based on the analysis of the research results, the optimum method of the spent sorbent separation was selected - separation of the suspension of purified ammonium-containing effluents - spent sorbent under the action of gravity. Indicators of optimization of complex process of sewage treatment from ammonium ions are offered.

Characterization of the remediation of chromium ion contamination with bentonite by terahertz time-domain spectroscopy

Heavy metal pollution of agricultural and urban soils limits economic progress in the rapidly developing society. Terahertz technology is applied to detect heavy metal pollutants under existence of multiple pathways of their dissemination. In this study, terahertz time-domain spectroscopy (THz-TDS) is employed as an advanced probing technique in combination with traditional detecting methods to measure the adsorption ability of trivalent chromium ions on bentonite. The concentration of chromium ions and the weight of bentonite are known to influence on the adsorption capacity of the latter. It is tested here by both qualitative and quantitative measurements of two mentioned parameters. The adsorption process of chromium ions by bentonite is monitored using THz-TDS. The adsorptions signal from samples at 0.5 THz gradually increases with the increase of bentonite weight or chromium ion concentration. It would appear to indicate that terahertz could be used for quantitative detection of metal ions. Secondly, the ratios of results obtained by inductively coupled plasma mass spectrometry (ICP-MS) and the THz-TDS ones are stabilized at 0.105 ± 0.014 as the bentonite weight or chromium ion concentration increase. Such finding confirms that terahertz technology can be used for the quantitative detection of metal ions. Using the relationship between the ICP-MS test results and the THz-TDS ones, the amplitude value of bentonite is obtained to be 13.925 at the concentration of chromium ions of 0.05 mol/L, the mass of bentonite sample involved in adsorption of 1.5 g, and the detection frequency in THz-TDS measurements of 0.5 THz. The adsorption coefficient of bentonite is calculated to be 1.44%. Increase of the chromium ion concentration to 0.2 mol/L, and the mass of bentonite involved in adsorption to 3 g leads to the increase of the amplitude corresponding to adsorbed chromium ions to about 19.463, and the adsorption coefficient to about 2.1%. Obtained results demonstrate that terahertz technology is promising to meet the ever-increasing requirements in mineral analyses for rapid detection of chemical contaminants and measurement of the adsorption efficiencies of materials.

Three-dimensional lattice Boltzmann simulation of reactive transport and ion adsorption processes in battery electrodes of cation intercalation desalination cells

Cation intercalation desalination (CID) has gained great popularity in the field of water desalination because of its excellent desalination performance. Due to lack of understanding of the relationship between electrode microstructures and reactive adsorption processes in CIDs, the further development of high-performance CID electrodes has been hindered. To this end, the influences of electrode microstructures on the desalination performance of CID cells were investigated from the pore-scale level in this work. The three-dimensional microstructures of porous electrodes are first reconstructed by an improved random generation method. Based on the reconstructed porous electrodes, the flow, mass transfer and intercalation reaction processes under the constant current are simulated using the lattice Boltzmann method. The effects of applied current density, porosity and size of active particles on the change of liquid-phase sodium concentration and Na-intercalated degree in the solid phase are evaluated. The simulation results show that increasing the current density can accelerate the ion intercalation and desalination rates. During the desalination, the ion concentration is unevenly distributed in the pores of porous electrodes, and the intercalation degrees are different along the electrode thickness direction and in the particle radial direction. The increase of porosity can alleviate the concentration polarization of liquid-phase sodium ion and reduce the difference of particle intercalation degree between the front- and back-sides of the electrode. In addition, the increase of porosity can accelerate the desalination process, but cannot improve the total salt removal. Reducing particle size can shorten the time for particles to reach the sodium-rich state, but it can aggravate the polarization of sodium ion concentration in the liquid phase at both ends of the electrode. This work reveals the ion intercalation behavior in the CID and its relationship with the electrode microstructures, and may provide useful information for the design and research of CID.

Sintesis Zn-BDC dengan Metode Sonokimia dan Aplikasinya Pada Proses Adsorpsi Ion Logam Pb2+

The heavy metal ion pollution such as lead (Pb2+) in wastewater is an environmental problem that needs to be solved. The adsorption method has been reported to have good potential as an alternative method for reducing heavy metal contents in aquatic environment. The most widely used adsorbent media are porous materials with a large surface area and low density. Metal Organic Frameworks (MOFs) are a type of porous material that is widely applied in various fields, such as fuel purification, solvent recovery, gas storage, and adsorbents. Lead(II) is a heavy metal ion that can pollute the environment and endanger humans. This study aims to synthesize MOFs and apply it to the Pb2+ adsorption process. In this research, MOFs type Zn-BDC or MOF-5 were synthesized by sonochemistry method at 60 ℃ as adsorbent for Pb2+ ion. Characterization of the adsorbent by FTIR showed the presence of functional groups C=O, C-H, and Zn-O which indicated the formation of the MOF-5 compound. The concentrations of Pb2+ ions were analyzed using Atomic Absorption Spectrophotometer (AAS). The experimental results show the optimum conditions for the adsorption process at pH 5 for 60 minutes with adsorption efficiency reaching 93.41%. Testing the adsorption isotherm model showed that the Pb2+ ion adsorption process using Zn-BDC as an adsorbent followed the Langmuir isotherm model with the R2 value of 0.9986.

Adsorption of Nutrient Ions into Biofilm Matrices of Natural Microbial Consortium

The presence of nutrient ions significantly affects the biotic components in the ecosystem, including the microbial consortium. Nutrient ions are an essential part of the aquatic ecosystem, which significantly affects microbial life. Most microbes live by forming biofilms that can uptake nutrient ions from the surrounding water. However, studies reporting the characteristics of uptake of nutrient ions by biofilms of the natural microbial consortium have been rarely reported. Understanding the uptake characteristics of cationic and anionic nutrients is an essential foundation for understanding biofilms as the predominant habitat of aquatic microbes. This study aims to analyze the adsorption characteristics of cationic nutrient (ammonium) and anionic nutrient (nitrate) by biofilm matrices. This study indicates that cationic nutrients can be adsorbed more into the biofilm matrix than anionic nutrients. The adsorption process of nutrient ions by biofilms is a fast process that allows the concentration of nutrient ions inside the biofilm matrix to be much higher than the surrounding water. According to the results of this study, the passive uptake of nutrient ions into the biofilm matrix is an important ecological factor providing nutrient ions for aquatic microbial life.

Investigation of the process of desalination of the concentrate of reverse osmosis plants by energy waste

PURPOSE. To investigate the cleaning process of the reverse osmosis water filtration system (ROWFS) concentrate with energy waste, to obtain and determine its quality indicators, to study the mechanism of sulfate and chloride ions adsorption by sorption material on the basis of energy waste, to consider the process of sulfate and chloride ion adsorption by this sorption material under static and dynamic conditions.METHODS. The method of variable weights was used to determine the adsorption capacity of the sorption material. Methods of titrimetric and photocolorimetric analysis were used during determining of water quality indicators.RESULTS. In this paper the technology of desalination of the ROP concentrate by the adsorption method was studied. Under static conditions the adsorption isotherm has been constructed. On the basis of ground sludge the granular sorption material has been developed. The possibility of using ionexchange filters with granular loading has been considered, the adsorption curve under dynamic conditions has been constructed.CONCLUSION. The sorption based on energy waste - carbonate sludge material for the purification of ROWFS concentrate has been developed. Adsorption isotherms of sulfate and chloride ions were constructed on the basis of experimental data. For investigation the purification of the ROWFS concentrate under dynamic conditions the granular sorption material was obtained. The adsorption technology of ROWFS concentrate purification from sulfate and chloride ions by energy waste is presented.

Cover Feature: Transfer Mechanism of Anthracycline Antibiotics and Their Ion Association with PAMAM Dendrimer at Liquid|Liquid Interfaces (ChemElectroChem 13/2022)

The Cover Feature illustrates ion transfer and adsorption processes of anthracycline antibiotics affected by the dendritic polymer at liquid|liquid interfaces. More information can be found in the Research Article by T. Takami et al.

Low-Cost RSAC and Adsorption Characteristics in the Removal of Copper Ions from Wastewater

Adsorption is a typical method for treating copper-containing wastewater. Fly ash and steel slag both have a good adsorption performance, and activated clay is added in this study, too. In this study, the performance of residue and soil adsorption composite (RSAC) particles for copper ion adsorption was discussed through the substrate ratio and the influence mechanism, to achieve the win–win effect of industrial waste reuse and copper ion wastewater treatment. The results indicated that adsorption time, dosage, initial copper ion concentration, coexisting ions, and temperature showed different effects on the adsorption, respectively. Additionally, the adsorption kinetic study showed the removal of copper ions by adsorption of RSAC particles was in accordance with quasi-primary kinetic model and quasi-secondary kinetic model. The adsorption thermodynamics study shows the adsorption process of ΔG0 < 0, ΔH0 > 0 and ΔS0 > 0, indicating that the process of copper ion adsorption by RSAC particles was spontaneous, heat-absorbing, and entropy-increasing. The research demonstrates that RSAC particles have a certain adsorption capacity for copper ion.

Graphene Oxide@Heavy Metal Ions (GO@M) Complex Simulated Waste as an Efficient Adsorbent for Removal of Cationic Methylene Blue Dye from Contaminated Water.

Graphene oxide (GO) was heavily used in the adsorption process of various heavy metal ions (such as copper (Cu) and iron (Fe) ions), resulting in a huge waste quantity of graphene oxide@metal ions complex. In this research, the authors try to solve this issue. Herein, the GO surface was loaded with divalent (Cu2+) and trivalent (Fe3+) heavy metal ions as a simulated waste of the heavy metal in various removal processes to form GO@Cu and (GO@Fe) composites, respectively. After that, the previous nanocomposites were used to remove cationic methylene blue (MB) dye. The prepared composites were characterized with a scanning electron microscope (SEM), transition electron microscope (TEM), Fourier transmission infrared (FTIR), Raman, and energy-dispersive X-ray (EDS) before and after the adsorption process. Various adsorption factors of the two composites towards MB-dye were investigated. Based on the adsorption isotherm information, the adsorption process of MB-dye is highly fitted with the Langmuir model with maximum capacities (mg g−1) (384.62, GO@Cu) and (217.39, GO@Fe). According to the thermodynamic analysis, the adsorption reaction of MB-species over the GO@Cu is exothermic and, in the case of GO@Fe, is endothermic. Moreover, the two composites presented excellent selectivity of adsorption of the MB-dye from the MB/MO mixture