Adsorption System Research Articles

Methylene Blue Adsorption Using Boric Acid Functionalized Activated Carbon: Kinetics, Isothermal, and Thermodynamic Studies

AbstractIn this study, the activated carbon (AC) was prepared from Sesbania sesban plant stem. Boric acid (H3BO3) was used as an activating agent. During calcination, the optimized temperature was kept upto 500 °C for 2 h. The prepared adsorbents were characterized using various techniques such as FT‐IR, scanning electron microscopy, energy dispersive x‐ray spectroscopy, and thermogravimetric analyzer. The prepared adsorbents were used for the removal of methylene blue (MB) dye adsorption. The adsorption experiments were conducted at different pHs such as (2–11), doses (0.0025–0.020 mg), times (30–300 min), MB initial concentrations (100–600 mg L−1), and temperatures (298–318 K), respectively. The maximum MB uptake capacity of the prepared adsorbent was 1380 mg g−1 under optimized adsorption conditions. Furthermore, the kinetic study is well described by pseudo‐second order, whereas the isothermal study showed the Freundlich isotherm was better followed by the equilibrium data. Based on thermodynamic studies, the negative values of ΔG° and ΔH° revealed that the MB adsorption process is spontaneous and exothermic in nature. However, the negative ∆Sxg° value indicates that solid‐solute interaction decreased randomness in the adsorption systems. The overall studies of AC showed that it was better to remove MB from an aqueous solution.

First-principles calculation of ZrS2 as anode material of aluminium ion battery

Developing low-cost, high-stability, and high-performance new ion battery anode materials is beneficial for the rapid development of ion batteries in fields such as rail transit, electronic products, and aerospace. In this work, the first-principles calculation method was used to study the feasibility of ZrS2 monolayer as an anode material for Al ion batteries. The Al ions adsorbed in the strain system tend to bind to the ZrS2 monolayer. In the adsorption system, the adsorption of Al increases the conductivity of the system. The theoretical specific capacity of Al under full load is 690.303 mAh/g. The average open circuit voltage (OCV) is calculated to be 0.635 V. The diffusion barrier of Al ions is 0.071 eV. ZrS2 monolayer is an attractive anode material for ion batteries.

Evaluation of Ferric Ion Adsorption On The Surface Imprinting Adsorbent

<span lang="EN-AU">Rapidity in technological aspects encourages industrial sector to utilize and apply the latest technology to accelerate and optimize production in its field. Thus, waste from industry polluting various aspects of environment, such as water, gives rise to environmental impacts. Heavy metals, including iron, are one of the most common and dangerous pollutants often found in water environments. Therefore, consideration of methods for heavy metal separation from water becomes important. The adsorption method has been used for separating heavy metals because of its simplicity, thus effectively cuts energy consumption and costs in process. However, heavy metal characteristics in water can vary depending on the element. Consequently, understanding the heavy metal characteristics in water is important, hence capable of formulate appropriate and effective adsorption systems. This study, Fe(III)-IIPs was applied to adsorb and separate iron from water through repeated adsorption with parameter improvements. The pH parameter plays an important role, with ion competition happens at pH <2 and the formation of iron hydroxide species at pH >4.5, which results in adsorption inhibition. The modeling of adsorption kinetic equation was found that the adsorption system carries chemisorption characteristics, with adsorption capacity of 11.15 mg/g and reaction rate constant of 19 min<sup>-1</sup>.</span>

Immobilized chitosan as an efficient adsorbent for columnar adsorption of Cr (VI) from aqueous solution

The current effort focuses on creating an effective adsorbent for Cr (VI) adsorption due to the growing need to address Cr (VI) pollution in aqueous solutions. Chitosan, a biopolymer and polysaccharide with several functional sites, is immobilized on alginate using the ion exchange technique. Both prior to and following Cr (VI) adsorption, the material's shape, crystallinity, and functional groups are reported. Immobilized chitosan was employed to adsorb Cr (VI) in a fixed bed column with variable operational parameters (flow rate, initial chromium content, and bed height). The analysis of breakthrough curves showed that at a flow rate of 10 mL/min, Cr (VI) concentration of 50 mg/L and a bed height of 18 cm, a maximum adsorption of 78.41 % was achieved. The adsorption system and the breakthrough curves were thoroughly understood by using Thomas, Yoon-Nelson and Adams-Bohart kinetic models. There is promise for the large-scale use of synthesized immobilized chitosan because the current adsorption process fits the Thomas and Yoon-Nelson model well and confirms the homogenous bed, low mass transfer resistance, and constant operating conditions throughout the experiment. Furthermore, an exploration of the adsorption mechanism is undertaken and the outcomes are compared with existing literature. The regeneration and reuse tests up to four cycles provided insight into the immobilized chitosan's stability, dependability, and potential for scaling up.

Process swing adsorption with selective purge gas recirculation (PSA-SPUR): Adsorption process technology optimised for separation of heavy component from a gas mixture and its design for CO2 capture through Equilibrium Theory analysis

PSA-SPUR (Pressure Swing Adsorption with Selective Purge Gas Recirculation) has been developed aimed at separating the most strongly adsorbing component from a gas mixture at high product purity and recovery. The innovative strategy for designing a Pressure Swing Adsorption system features recycling its purge gas stream exiting the column and mixing it back into the feed. This operation enriches the mixed feed with an elevated fraction of the heavy component during the adsorption step, thus enhancing the PSA’s performance greatly. Reusing the purge gas helps significantly increase the product recovery compared to conventional methods where purge gas is simply discarded or taken as a low-quality product. For theoretical analysis of a PSA-SPUR system, a bespoke Equilibrium Theory model was developed and solved successfully, providing valuable insights into the performance of the PSA-SPUR system designed for capturing CO2 from a flue gas. The study revealed that there exists an optimum extent of purging that maximises the heavy component mole fraction in the mixed feed, leading to the best possible feed throughput of the adsorption system. Furthermore, the effects of the desorption pressure and feed composition on the PSA-SPUR system’s performance were investigated. The results indicate that the CO2 capture PSA-SPUR system using commercial zeolite 13X has excellent potential to achieve very high product purity and recovery, being allowed to operate at moderate vacuum pressures without having to compress the flue gas feed, even when the gas feed contains less than 10 mol% CO2.

Assessment of Cerium Adsorption Potential of Phosphoric acid Activated Biochar in Aqueous System: Modelling and Mechanistic Insights

Cerium pollution in waterbodies by improper industrial waste disposal is a major concern due to its detrimental impacts on the environment. Therefore, treatment of cerium-contaminated water is inevitable. Hence, this study is focused on the remediation of cerium pollution using phosphoric acid-activated biochar (PPMB) as an adsorbent, synthesized upon pyrolytic activation of palmyra palm male flower-based pristine biochar (PMFB) with H3PO4 at 500°C. The physico-chemical surface properties of PMFB and PPMB were evaluated through various microscopic and spectroscopic analyses. The key parameters such as biochar dosage, pH, temperature, contact time and initial cerium concentration were optimized as 0.5 g/L, 5.0, 303 K, 180 min and 50 mg/L respectively via batch adsorption. Pseudo-second order kinetic and Toth isotherm are the best-fitted models. The thermodynamic parameters including ΔG◦ (-30.4707±0.7618 kJ/mol at 303 K), ΔH◦ (16.1499±0.78 kJ/mol), and ΔS◦ (153.617±3.8404 J/mol/K) conveying that cerium adsorption onto PPMB was spontaneous, endothermic, and highly disordered at PPMB-bulk adsorption medium interface. Precipitation, electrostatic attraction, and surface complexation are predicted to be the predominant mechanisms for the chosen PPMB-cerium adsorption system. Moreover, cerium phytotoxicity on Vigna radiata explains the real-time applicability and feasibility of cerium adsorption using PPMB. Thus, the key findings of this study specified that the higher adsorption capacity of PPMB (141.3484±6.9856 mg/g) contributed by the incorporated phosphate groups, predominant mesoporosity, SSABET of 230.559 m2/g and anionic surface at a wider pH range (pH>3.08) make PPMB as efficient, economically feasible and environmentally friendly adsorbent for cerium adsorption in aqueous system.

Theoretical Investigation of Rhodium-Decorated Gallium Nitride Nanotubes for Sulfur Hexafluoride Decomposition Products Sensing and Scavenging Applications.

Gas-insulated switchgear (GIS) plays an important role as a modern power distribution device in power plants and power stations, which is commonly filled with SF6 insulating gas. During the equipment operation, the inevitable partial discharge causes SF6 to be broken down into gas (SF4, SOF2, SO2, and H2S), which degrades the insulation performance of the GIS. This paper is devoted to the detection of partial discharge and the removal of SF4 and SOF2, which are not conducive to insulation, by exploring new gas-sensing materials for characteristic gas detection. Based on first-principles calculation, on the one hand, the most stable adsorption configurations of rhodium-decorated gallium nitride nanotubes (Rh-GaNNTs) and gas adsorption systems were obtained. On the other hand, the doping and adsorption mechanisms were analyzed by band structure, density of states, deformation charge density, and molecular orbital theory. Subsequently, the gas-sensitive performance of Rh-GaNNTs for these four impurity gases was evaluated by analyzing the sensing response and recovery time. The adsorption stability and recovery time of Rh-GaNNTs to these gases are ranked as SF4 > SOF2 > SO2 > H2S; the order of influence of gas adsorption on sensitivity response is H2S > SO2 > SF4 ≈ SOF2. Calculation results show the potential of Rh-doped surfaces as reusable H2S and SO2 sensors and suggest their use as gas scavengers to remove SF4 and SOF2, especially SOF2.

Evaluation of a triethylenetetramine-chitosan derivative for the removal of palladium ion from an intricate adsorbate system

Evaluation of a triethylenetetramine-chitosan derivative for the removal of palladium ion from an intricate adsorbate system

Hydroxyl and amino co-modified imidazole based ionic liquid functionalized TS-1 molecular sieve for efficient CO2 capture

Herein, an integrative solid adsorbent of [AHOPMIm]Cl with hydroxyl and amino groups functional sites modified TS-1 molecular sieve is designed and fabricated for efficient CO2 adsorption. The optimal [AHOPMIm]Cl/TS-1 exhibits 73% enhancement in CO2 adsorption capacity compared with the TS-1 molecular sieve, even outperforming other state of the art adsorbent systems. The greatly improved CO2 adsorption capacity is mainly attributed to the strong adsorption of amino groups on the ionic liquids surface, which can form low-temperature stable amino ester species. Moreover, it is preserved that the hydroxyl groups on the surface of ionic liquids can form stable hydrogen bonds with oxygen atoms in CO2, and coordinate with amino groups to capture CO2 from different directions based on in situ DRIFTS and DFT. The porous TS-1 molecular sieve provides a structural basis for the uniform dispersion, effective support, and enhanced CO2 adsorption capacity of ionic liquids. A new design concept for constructing ionic liquid-based composite adsorbent with dual functional sites using TS-1 molecular sieve as a carrier is provided, and the avenues for efficient CO2 adsorption are paved.

Atomic-Level Insights into the Adsorption of Methyl-Substituted Quinoxalinones on Fe(110): A Dispersion-Corrected DFT Analysis.

Corrosion of metallic equipment is a critical issue across various industries, necessitating the development of advanced protective strategies. This study utilized dispersion-corrected density functional theory (DFT) with Becke-Johnson D3(BJ) to examine the atomic-level adsorption of quinoxalinones on Fe(110) surfaces, focusing on optimizing substitution strategies to enhance corrosion inhibition. Three quinoxalinones, quinoxalin-2(1H)-one (QNO), 3-methylquinoxalin-2(1H)-one (QNOM), and 3,7-dimethylquinoxalin-2(1H)-one (QNO2M), were investigated in various configurations and protonation states. Protonated quinoxalinones demonstrated a stronger surface affinity, primarily interacting through oxygen atoms and conjugated systems, with greater energetic stability compared to neutral molecules, driven by enhanced electrostatic interactions and charge transfer mechanisms. The parallel adsorption configuration was more stable than the perpendicular mode, which in some adsorption systems did not form bonds with the iron surface. Notably, the presence of methyl substitutions did not significantly enhance adsorption strength; QNO exhibited higher energetic stability due to reduced steric interference, which maintained its planarity. Projected density of states (PDOS), electron density difference (EDD), and electron localization function (ELF) analyses confirmed the importance of charge transfer between quinoxalinone active sites and the 3d orbitals of iron in stabilizing the adsorption of molecules. These findings underscore the importance of judicious quinoxalinone functionalization to preserve their efficacy as corrosion inhibitors.

A modified dubinin-radushkevich model describing the cryogenic adsorption of 4He on carbon materials

The 4He and 3He adsorption characteristics of porous materials serve as important references for designing and optimizing cryogenic components or systems, including adsorption pumps, helium adsorption refrigerators, and gas-gap heat switches. In this study, various types of activated carbon and carbon nanotubes were measured for their 4He adsorption characteristics in the range of 3–20 K and 1–18000 Pa. Parameters such as micropore volume and adsorption potential energy of porous materials were analyzed through Dubinin-Radushkevich (DR) model. A modified DR model describing the monolayer adsorption of 4He on different carbon-based adsorbents was developed in this study, greatly facilitating the design of adsorption systems. Further, the 4He adsorption model was applied to gas-gap heat switches, and a numerical model of the 4He gas-gap heat switch was established, which accurately predicts the actuation characteristics of several heat switches.

The gas-sensing mechanism of Nb2C monolayer for SF6 decomposition based on the DFT study

Abstract In addressing malfunctions in gas-insulated switchgear (GIS) systems, it is imperative to have a real-time tracking system for SF6 decomposition products to guarantee the safety and reliability of the equipment's operation. Although a variety of gas detection technologies are currently available on the market, low-power gas detection devices for SF6 decomposition products are still in the development stage, and technological advances in this area are of great significance for improving the reliability of GIS systems. Based on the density functional theory (DFT), the Nb2C crystal surface structure was established and six adsorption structures of SO2, H2S, SOF2, SO2F2, HF and CO gas molecules on Nb2C crystal surface were constructed by geometrical optimization in this paper. The gas-sensitive properties of each adsorption system were explored in terms of adsorption energy, charge transfer, electron density, density of states and recovery time. The results showed that the Nb2C crystal surface was unfit HF and CO gases detection, both of which showed weak physical adsorption; the adsorption energies of SO2, H2S, SOF2, and SO2F2 on the Nb2C crystal surface were -1.846 eV, -1.081 eV, -5.270 eV, and -10.582 eV, respectively, and all of them were strong chemical adsorption. It was further shown by theoretical recovery time calculations that the Nb2C crystal surface can act as SOF2 and SO2F2 gas scavengers, and are able to desorb H2S (4.69 s) and SO2 (2.26 s) gases by appropriately increasing the temperature, but the Nb2C crystal surface is more suitable for use as a low-power gas-sensitive material for H2S gas detection. Therefore, Nb2C is anticipated to be a promising material for high response, low-power consumption and fast recovery for H2S gas detection in SF6 decomposition gas.

Polyurethane and fiber- based photothermal device for solar evaporation and crude oil adsorption

Photothermal materials exhibit significant potential for marine applications, yet their efficiency and durability require enhancement. This study presents a dual-layer photothermal device that integrates a polyurethane light absorption layer with a wood sponge layer, designed for water transport and thermal insulation. The wood sponge’s hydrophilicity and effective water transport properties improve water supply while minimizing heat loss. Under sunlight, the device achieves a surface temperature of 63.2°C and an evaporation rate of 1.86 kg/m2/h for seawater desalination. The porous design of both layers ensures salt resistance during extended desalination processes. Furthermore, the incorporation of disulfide bonds into the polyurethane enhances the material’s self-healing properties, enabling sustained performance even after prolonged use, thus extending its service life. Additionally, the device demonstrates effective crude oil adsorption capabilities attributed to its photothermal efficiency and porosity. This innovative design provides valuable insights for advancing solar-driven evaporation devices and crude oil adsorption systems in marine environments.

Kinetics and Mechanism Study of Different Types of Surface‐Imprinted Polymers for CO2 Adsorption

ABSTRACTThe increased level of CO2 in the atmosphere has led to global warming and climate change. To mitigate these problems, solid adsorbents have become attractive materials for capturing excess CO2 in the post‐combustion method. Molecularly imprinted polymer (MIP) can be applied to prepare highly selective adsorbents that could capture CO2 molecules. The MIP was prepared using the surface imprinted polymer technique in this preliminary work. Only two types of support materials were used (graphite and silica gel) to screen the best support material that could enhance the CO2 adsorption capacity of the resulting adsorbent, which was analyzed using a fixed‐bed column reactor. Graphite‐imprinted polymer (GMIP) was found to be a good potential for CO2 adsorption. The Avrami model best described the adsorption system, while the fixed‐bed curve data fit the Yoon–Nelson model well. The semi‐empirical method was used to assess the interaction mechanism of the molecularly imprinted polymer with CO2 during adsorption. This investigation involved testing four different ratios of the template complex to functional monomers. The ratio of 1:4 (CO2:Allylthiourea) demonstrated the highest binding energy, with a higher formation of hydrogen bonds. Film diffusion and intraparticle diffusion were the main rate‐limiting steps that played vital roles at different stages of CO2 adsorption. This preliminary work has enhanced the development of MIP for CO2 adsorption and showcased the integration of computational approaches in tailoring specific MIPs.

Theoretical predictions of CO2, H2 and H2O adsorption mechanisms on M2C-MXene: Selectivity and potential application insights

M2C-MXenes, owing to their abundant adsorption sites, exhibit significant potential in CO2 capture, utilization, and storage (CCUS) and hydrogen energy applications, contributing to hydrogen utilization and global carbon reduction, and thus solving intractable energy and environmental problems. However, the extensive variety of M2C compounds poses challenges to the systematic evaluation of their applications in these fields. The exploration of the adsorption properties of M2Cs is a key fundamental aspect of these studies, and therefore, this study employs calculations across 456 adsorption systems to elucidate the adsorption mechanisms of 19 M2C compounds for small molecules (CO2, H2 and H2O). The results indicate that these M2C materials possess structural stability and metallic characteristics, with periodic variations in the d-band center aligning with trends in CO2 adsorption energy. Notably, molecular orientation impacts adsorption energy more significantly than adsorption sites, particularly for CO2, while M2C compounds primarily exhibit physical adsorption towards H2. Specifically, Sc2C preferentially adsorbs CO2 in atmospheric conditions, and shows chemical adsorption towards H2O, but exhibits negligible adsorption for H2; conversely, Cr2C demonstrates higher adsorption potential for H2. Both materials exhibit favorable thermodynamic stability, suggesting Sc2C is suitable for CCUS applications, while Cr2C holds promising prospects for hydrogen storage.

Dissolved organic matter-mediated adsorption behavior of benzophenones on functionalized covalent triazine frameworks

Adsorption is a highly efficacious technique for the remediation of organic micropollutants (OMPs). However, the presence of dissolved organic matter (DOM) frequently impedes adsorbent process, with insufficient attention given to this influence. This study systematically evaluates the adsorption performance of covalent triazine frameworks (CTFs) functionalized with electron-donating or electron-withdrawing groups for benzophenones (BPs). The adsorption capacities of SO3H-CTF, OH-CTF, and NH2-CTF for BPs were 512.11 μmol/g, 1356.27 μmol/g, and 1421.85 μmol/g, respectively. The adsorption mechanism is predominantly governed by π-π electron donor–acceptor (EDA) interactions, supplemented by hydrogen bonding, particularly in hydroxyl-containing BPs, with electrostatic interactions being relatively negligible. Functionalization with − OH and − NH2 groups increased the electron density in π-conjugated regions, enhancing BPs adsorption capacity, whereas − SO3H modification, due to its electron-withdrawing nature, acted as a π electron acceptor. Importantly, the mediating role of humic acid (HA) in the adsorption process was investigated. The CTF-BPs-HA ternary system can either inhibit/enhance π-π EDA interactions between π-electron donor/acceptor and BPs by adsorbing onto the CTF materials. The HA-mediated system primarily affects the film diffusion stage, with minimal impact on pore diffusion and inner surface adsorption. The oxygenated functional groups in HA slightly enhanced hydrogen bonding within the adsorption system, with negligible influence on electrostatic interactions. In the presence of HA, the overall adsorption capacity of SO3H-CTF decreased by 67.0 %, while that of OH-CTF and NH2-CTF increased by 120.9 % and 55.3 %, respectively. This study elucidates the electronic behavior modifications of functionalized CTFs during BPs adsorption and underscores the significant role of HA in interaction mechanisms, providing theoretical guidance for the design of advanced adsorbents to enhance pollutant removal efficiency.

The Performance and Mechanism of Solvothermal Synthesis of a Ca-Fe-La Composite for Enhanced Removal of Phosphate from Aqueous Solutions

Since it is a limiting nutrient element in rivers and lakes, the effective removal of phosphorus is key to alleviating eutrophication. In this study, the one-pot solvothermal method was adopted to prepare an environmentally friendly Ca-Fe-La composite. This is an amorphous material with a large specific surface area of 278.41 m2 g−1. The effects of coexisting anions and pH on the phosphate removal performance were explored. Phosphate adsorption mechanisms were revealed by various characterization techniques. The phosphate adsorption obeyed the fractal-like pseudo-second-order (PSO) kinetic model, implying that the overall adsorption system was highly heterogeneous. In this work, the maximum adsorption capacity predicted by the Langmuir model was 93.0 mg g−1 (as PO43−-P). The phosphate-loaded Ca-Fe-La composite could be used as a slow-release fertilizer, achieving waste management and resource utilization. The presence of SO42−, CO32− and HCO3− anions inhibited the phosphate adsorption significantly. It was unfavorable for phosphate removal at a high pH value. Inner-sphere complexation and electrostatic attraction were mainly responsible for phosphate adsorption onto the Ca-Fe-La composite.

Integration of cadmium sulfide quantum dots with calcium alginate microbeads for dual-functional mercury (II) ion sensing and removal

Mercury contamination poses human health as well as ecosystem at significant risks. This study introduces a novel approach for the selective detection with removal of Hg2+ ions from aqueous media by developing a dual functional adsorbent that combines calcium alginate microbeads (FMCAB) with capped cadmium sulfide quantum dots (CdS QDs). CdS QDs immobilized on calcium alginate microbeads in magnetite facilitated efficient separation from the adsorption system under an external magnetic field. The fluorescence properties of CdS QDs remain largely unaffected before and after adsorption of Hg2+ ions on FMCAB, enabling selective monitoring of these ions. The adsorbent demonstrated a high adsorption capacity of around 160 μg/g and exhibited a quick and effective process. FMCAB evidenced selectivity over the other metal ions with limits of detection 12.9 μM. The results from this research pave the way for novel applications of FMCAB for heavy metal ions sensing probes and its removal.

Monte Carlo calculations taking into account the DLP theory to study multilayer adsorption of C2H4 and CF4 on graphite

Physisorption potentials are useful for deducing the properties of adsorption systems. The adsorption behavior is a consequence of the actual potential that describes the interactions among the adsorption system. Determining the actual isotherm is a test for the correctness of a calculated adsorption potential. The physisorption interactions decrease with the film thickness, d, according to a power law as −γ/d3, where γ is the Van der Waals coefficient. In the Dzyaloshinskii, Lifshitz, and Pitaevskii (DLP) theory, γ is a function of d where γ(d) decreases with d. In the present work, the general theory of Van der Waals forces, given by DLP, is used to derive a more exact treatment of interactions among the physisorbed systems. The Monte Carlo method is used to investigate multilayer films using a lattice gas model adsorption isotherm. Critical temperatures are determined for ethylene (C2H4) and tetrafluoromethane (CF4) on graphite. These systems exhibit comparable behavior. Unlike the findings of mean field theory, our data shows that the critical temperature rises gradually as the layer number increases. On the other hand, the comparison with experimental results and measurements has shown that our calculations are more reliable and provide a better approximation in predicting film thickness. Our isotherms appear to be in better agreement with the experimental ones.

Heavy Metal Removal from Water Using Graphene Oxide in Magnetic-Assisted Adsorption Systems: Characterization, Adsorption Properties, and Modelling

This study investigated the adsorption properties of graphene oxide in a magnetic-assisted adsorber for the depollution of water containing heavy metals. Two samples of graphene oxide with different surface chemistry were synthetized and assessed using the magnetic-assisted adsorption systems. One graphene oxide sample exhibited a dual magnetic behavior presenting both diamagnetic and ferromagnetic phases, while the other graphene oxide was diamagnetic. The adsorption properties of these graphene oxide samples for removing Pb2+ and Cu2+ were tested and compared with and without a magnetic field exposure. The results showed that the Pb2+ removal increased using both graphene oxide samples in the magnetic-assisted configuration, while Cu2+ adsorption was less sensitive to the application of the magnetic field. A monolayer model was used to simulate all the heavy metal adsorption isotherms quantified experimentally. It was concluded that the adsorption mechanism designed to remove Pb2+ and Cu2+ using tested graphene oxide samples was mainly multi-ionic where two metallic cations could interact with one active site (i.e., oxygenated functional groups) from the adsorbent surface. The oxygenated surface functionalities of graphene oxide samples played a relevant role in determining the impact of magnetic field exposure on the heavy metal removal efficacy. Magnetic-assisted adsorption using graphene oxide is an interesting alternative to reduce the concentration of Pb2+ in polluted effluents, and it can also be applied to improve the performance of adsorbents with a limited concentration of oxygenated functional groups, which usually show poor removal of challenging water pollutants such as toxic heavy metals.