Magnetic Nanosorbent Research Articles

Ultrasound-assisted solid phase microextraction-HPLC method based on Fe3O4@SiO2-NH2-molecularly imprinted polymer magnetic nano-sorbent for rapid and efficient extraction of harmaline from Peganum harmala extract

In the present study, a magnetic molecularly imprinted polymer (MMIP) was synthesized for the extraction of harmaline from Peganum harmala by dispersive solid-phase microextraction (DSPME). The MMIP for selective and intelligent extraction of harmaline with excellent functionality and high selectivity was synthesized using the sol-gel method with functionalized superparamagnetic core-shell nanoparticles, ethylene glycol dimethacrylate (EDMA) as a cross-linker, methacrylic acid (MAA) as a functional monomer, and 2,2-azobisisobutyronitrile (AIBN) as a porogen. To study the properties and morphology of the coated polymer, FT-IR spectroscopy, FESEM, TEM images, and VSM were used. The DSPME-HPLC-UV equipment was used to quantify and analyze the data obtained from harmaline extraction. In this research, the efficiency of the synthesized polymer in harmaline extraction was modeled and optimized using the response surface methodology based on central composite design (RSM-CCD). In addition, for modeling the isotherm of harmaline sorption by the MMIP, Langmuir and Freundlich isotherm equations were used. The obtained results showed that the extraction of harmaline with the MMIP was well described with Freundlich isotherm. The results of the validation of the method showed that the measurement of harmaline in the concentration range of 1.0–4000 ng mL−1 followed a linear relationship (R2 = 9986.0). Moreover, the accuracy or repeatability index (% RSD) was determined to be < 10, and the LOQ and LOD values were 0.526 and 0.158 ng mL−1, respectively. The results of this study showed that the DSPME technique by using the synthesized MMIP as an effective sorbent with high efficiency and capacity could be utilized for pre-concentration and extraction of harmaline from real and complex samples.

Fabrication of silane-modified magnetic nano sorbent for enhanced ultrasonic wave driven removal of methylene blue from aqueous media: Isotherms, kinetics, and thermodynamic mechanistic studies.

In this study, we report a simple and economic one-pot synthesis of magnetite (Fe3O4) nanostructure and its modification with tetraethyl orthosilicate by coprecipitation method. The synthesized (Fe3O4@SiO2) nano sorbent was applied for enhanced adsorptive removal of methylene blue by ultrasonic wave driven batch experiments. After successful synthesis, the nanostructure was characterized for their physical structure by FT-IR, VSM, TEM, and XRD. For the maximum adsorptive performance of nano sorbent, various parameters were optimized, such as dose, pH, time, concentration, and temperature. The adsorption mechanism was best fitted by Langmuir isotherm with a maximum capacity of 148.69 mg/g, while kinetics best fitted by pseudo-second-order kinetic. The synthesized nano sorbent was successfully applied for enhanced adsorptive removal of toxic methylene blue from aqueous media. The proposed method is promising and effective in terms of simplicity, cost operation, green energy consumption, reproducible, excellent reusability, and magnetically separability with fast kinetic.

Reusable pectin‐coated magnetic nanosorbent functionalized with an aptamer for highly selective Hg2+ detection

AbstractA pectin‐coated magnetite nanoparticle functionalized with Hg2+‐specific aptamer was developed to obtain a magnetic nanosorbent having high selectivity toward Hg2+ and facile reusability. The aptamer labeled with biotin was immobilized on pectin‐coated MNP conjugated with streptavidin through the specific biotin–streptavidin interaction to obtain an aptamer‐functionalized nanosorbent. Pectin coated on the particle improved its stability and dispersibility in water, while thymine in the aptamer played an important role as a recognition element, which can bind to the Hg2+ target via T–Hg2+–T complexes. The nanosorbent showed a linear concentration, ranging from 2.8 to 700 μg/L, with the limit of detection of 0.8 ± 0.2 μg/L and limit of quantitation of 2.8 ± 0.2 μg/L for the detection of Hg2+. It showed high selectivity with good tolerance toward Hg2+ in the presence of other metal ions. The system can be repeatedly used for up to 10 cycles of Hg2+ adsorption with only slight changes in its performance. In addition, satisfactory recoveries were also obtained for the detection of Hg2+ in real water samples. This nanosorbent might be a promising tool for extended applications in biological and analytical fields.

On the efficient removal, regeneration and reuse of quaternary chitosan magnetite nanosorbents for glyphosate herbicide in water

In this study, magnetic nanosorbents consisting of magnetite (Fe3O4) cores coated with trimethyl chitosan (TMC)-silica hybrid shells were synthesized using a one-step coating procedure, and their application in the adsorptive removal of glyphosate (GLY) from artificial (ultra-pure) and real water (wastewater) samples was investigated. In synthetic laboratory samples, the magnetic nanosorbents decreased realistic environmental concentrations of GLY to values that are below the maximum permissible value (0.1 μg/L) defined by the European Directive of Drinking Water. In spiked wastewater samples, the nanosorbents at a dose of 2.5 mg/mL removed 76.8% of the GLY (initial concentration of 3.0 μg/L), demonstrating the potential application of these nanosorbents in aqueous matrices of complex nature. The adsorption performance towards GLY was assessed by varying the operational conditions in ultra-pure water, including initial GLY concentration, pH, contact time and sorbent dose. The magnetic nanosorbent showed fast adsorption of GLY, with the maximum adsorption being reached within 60 min contact time attaining a maximum of 97% removal for the GLY concentrations tested. The kinetic data were consistent with the pseudo-first-order model. The equilibrium sorption data was better described by Sips model, with a maximum adsorption capacity of 3.04 mg/g. The magnetic nanosorbents could be reused after regeneration and the removal of GLY remained above 80% after 4 adsorption-desorption cycles. Our results indicate that assisted magnetic water remediation using recyclable TMC surface-modified nanosorbents is an efficient process for the elimination of glyphosate from ultra-pure water and real wastewater to meet water quality standards.

Application of core-satellite polydopamine-coated Fe3O4 nanoparticles-hollow porous molecularly imprinted polymer combined with HPLC-MS/MS for the quantification of macrolide antibiotics.

Core-satellite-structured magnetic nanosorbents (MNs) used for the selective extraction of macrolide antibiotics (MACs) were prepared in this study. The MNs (core-satellite polydopamine-coated Fe3O4 nanoparticles-hollow porous molecularly imprinted polymer) consisted of polydopamine-coated Fe3O4 nanoparticles (Fe3O4@PDA) "core" linked to numerous hollow porous molecularly imprinted polymer (HPMIP) "satellites" with bridging amine functional groups. It is worth mentioning that HPMIPs act as "anchors" for selectively capturing target molecules. Polymers were characterized using TEM, SEM, FT-IR, VSM, and TGA and applied as magnetic dispersive solid-phase extraction (MDSPE) sorbents for the enrichment of trace MACs from a complex food matrix prior to quantification by HPLC-MS/MS. Nanocomposites revealed outstanding magnetic properties (36.1 emu g-1), a high adsorption capacity (103.6 μmol g-1), selectivity (IF = 3.2), and fast kinetic binding (20 min) for MACs. The multiple advantages of the novel core-satellite-structured magnetic molecularly imprinted nanosorbents were confirmed, which makes us believe that the preparation method of the core-satellite MNs can be applied to other fields involving molecular imprinting technology.

Nanoengineered iron oxide-based sorbents for separation of various water pollutants: current status, opportunities and future outlook

Iron oxide based magnetic nanosorbents have emerged as a material of choice for treating a wide range of water pollutants owing to their higher removal efficiencies, faster kinetics, economic viability, better reusability and ease of separation.

Fitting a little-known isotherm equation to S-shaped adsorption equilibrium data

A research topic of current interest concerns the measurement and modeling of adsorption isotherms of water contaminants. The bulk of measured equilibrium isotherms exhibit the convex-upward or favorable curve shape, which can be described by the two-parameter Hill-Langmuir and Freundlich isotherms. An increasing number of recent studies have however reported S-shaped or sigmoidal equilibrium isotherms. Modeling such equilibrium data requires the use of isotherm equations with a highly flexible functional form. This work introduces a little-known isotherm useful for tracking the trajectory of S-shaped equilibrium data. This relatively simple three-parameter isotherm, first proposed by Krishnamurti in 1951, has theoretical merit because it is based on a co-operative adsorption mechanism. It is shown that previously reported S-shaped equilibrium data of water contaminants can be represented by the Krishnamurti isotherm. Specific examples discussed are (1) ammonium ion adsorption by the clay mineral sepiolite, (2) uptake of the antibiotic ciprofloxacin by a magnetic nanosorbent, and (3) fluoride ion removal by a layered double hydroxide adsorbent. Additionally, it is found that a modified form of the Krishnamurti isotherm is superior to its original counterpart. The original and modified Krishnamurti isotherms can be practically very useful to describe S-shaped equilibrium data and for adsorptive process modeling.

Smart Synthesis of Trimethyl Ethoxysilane (TMS) Functionalized Core-Shell Magnetic Nanosorbents Fe3O4@SiO2: Process Optimization and Application for Extraction of Pesticides.

In the current study, a smart approach for synthesizing trimethyl ethoxysilane–decorated magnetic-core silica-nanoparticles (TMS-mcSNPs) and its effectiveness as nanosorbents have been exploited. While the magnetite core was synthesized using the modified Mössbauer method, Stöber method was employed to coat the magnetic particles. The objective of this work is to maximize the magnetic properties and to minimize both particle size (PS) and particle size distribution (PSD). Using a full factorial design (2k-FFD), the influences of four factors on the coating process was assessed by optimizing the three responses (magnetic properties, PS, and PSD). These four factors were: (1) concentration of tetraethyl-orthosilicate (TEOS); (2) concentration of ammonia; (3) dose of magnetite (Fe3O4); and (4) addition mode. Magnetic properties were calculated as the attraction weight. Scanning electron microscopy (SEM) was used to determine PS, and standard deviation (±SD) was calculated to determine the PSD. Composite desirability function (D) was used to consolidate the multiple responses into a single performance characteristic. Pareto chart of standardized effects together with analysis of variance (ANOVA) at 95.0 confidence interval (CI) were used to determine statistically significant variable(s). Trimethyl ethoxysilane–functionalized mcSNPs were further applied as nanosorbents for magnetic solid phase extraction (TMS-MSPE) of organophosphorus and carbamate pesticides.

A new dendrimer-functionalized magnetic nanosorbent for the efficient adsorption and subsequent trace measurement of Hg (II) ions in wastewater samples

A new dendrimer-functionalized magnetic nanosorbent for the efficient adsorption and subsequent trace measurement of Hg (II) ions in wastewater samples was successfully synthesized. The synthesis is accomplished via the Michael addition reaction of the amino groups of the silica-coated magnetic nanoparticles (APTES-modified Fe3O4@SiO2) with the double bond of methyl acrylate followed by the amidation of the resulting methyl ester with ethylene diamine. Following that, some donor functional groups were attached to the dendrimer via a specific chemical reaction to offer a further selectivity to the dendrimer-based nanosorbent. Once the synthesis is accomplished, the as-prepared nanosorbent was characterized by several analytical techniques such as FT-IR, SEM, VSM, TGA and EDX. Following that, Hg (II) ions were adsorbed onto the active sites of the sorbent through the complexation with the dentates (-N, -S) of the dispersed sorbent, which seems to be the cornerstone of the adsorption process. In the next step, the ions were desorbed off the sorbent and measured by a cold vapor atomic absorption spectrometer (CV-AAS). The impact of a number of influential variables such as pH, sorbent dosage, adsorption time, elution features were assessed and subsequently optimized. Under the optimal conditions, a relatively wide linearity was obtained for the analyte of interest in the range of 0.08–6.0 μg/L with the correlation coefficients (R2) of 0.9922 and the method detection limit (MDL) was determined to be 0.03 μg/L. Satisfactory relative recoveries of the analyte varied within 90.0–106.7% with the relative standard deviations (RSD%) of 2.1–5.3%. In addition, a number of experiments with regard to the equilibrium adsorption isotherms of the target ion was performed which well fitted to the Langmuir isotherm model. Finally, the results indicated that the whole method was sensitive, effective and practical for the adsorption and trace measurement of Hg (II) in wastewater samples.

Facile preparation and application of AlxMgFe2-xO4 nanoparticles as a magnetic nano-sorbent for preconcentration of cadmium

A simple co-precipitation method was applied for the preparation of aluminum-doped magnesium ferrite (AlxMgFe2-xO4) nanoparticles. The prepared AlxMgFe2-xO4 nanoparticles was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The synthesized AlxMgFe2-xO4 nanoparticles was applied as an adsorbent for developing a novel magnetic solid-phase extraction method for the preconcentration of cadmium ion in aqueous samples, following its quantification by flame atomic absorption spectrometry. Based on the method validation, the method linear dynamic range was 0.2–24.0 ng mL−1 with a limit of detection of 0.05 ng mL−1. The intra- and inter-day precision of the developed method were evaluated by conducting five consecutive replicate experiments in one day and five days and the relative standard deviation percentages were obtained to be 2.6% and 3.5%, respectively. Under optimized conditions, the accuracy of the presented method was evaluated by the analysis of a certified reference sample. Moreover, the applicability of the developed method for Cd(II) ion determination was validated by preconcentration and determination of Cd(II) ion in various natural waters.

In situ formed magnetic chitosan nanoparticles functionalized with polyethylenimine for effective U(VI) sorption

The polyethylenimine-functionalized magnetic chitosan nanoparticles (MCN-PEI) are synthesized and characterized by elemental analysis, TEM, FT-IR, XRD, etc. The MCN-PEI exhibits a core–shell structure, and had a saturation magnetization of 18.7 emu/g (which is high enough for fast magnetic separation). The maximum U(VI) sorption capacity for MCN-PEI reaches 134.6 mg/g at pH 5.0 and 298 K. The good-fitting of both sorption kinetics by pseudo-second-order model and sorption isotherms by Langmuir model indicates chemisorption mechanism. The thermodynamic parameters indicate the spontaneous and exothermic nature for U(VI) sorption. Finally, the magnetic nano-sorbents can be efficiently desorbed by acidified EDTA solution for regeneration.

Spinel-type ferrite nanoparticles for removal of arsenic(V) from water.

Spinel ferrite particles (Fe3O4, MnFe2O4, and CoFe2O4) were investigated as magnetic nanosorbents for removing arsenic from spiked water samples. The nanosorbents were collected via magnetic separation from aqueous solutions spiked with an arsenic concentration that mimics the amount of this contaminant in real water samples. This research shows that using amounts of CoFe2O4 or MnFe2O4 as low as 40mg/L, the arsenic content in the contaminated water decreased for levels below the maximum admitted value by the World Health Organization for drinking waters (10μg/L). Moreover, these magnetic nanosorbents also showed good performance for As(V) sorption, when applied to aqueous matrices with variable ionic strength and in the mixtures of other several hazardous contaminants. The good performance observed for the MnFe2O4 and CoFe2O4 ferrites contrasts with the one observed for Fe3O4 nanosorbent, whose efficiency is lower in the removal of As(V) from water, nevertheless increased with the presence of other elements in solution.

Synthesis and characterization of chicken eggshell powder coated magnetic nano adsorbent by an ultrasonic bath assisted co-precipitation for Cr(VI) removal from its aqueous mixture

Chromium (VI) is one of the noxious heavy metals present in the effluents that pose a threat to the living environment. In this exploration, a magnetic nano sorbent was set up by nourishment squander chicken eggshell powder coated with iron oxide in co-precipitation assisted with an ultrasonic bath. The efficacy of CM magnetic nano adsorbent in Cr(VI) removal from its aqueous solution by batch adsorption was investigated. The characterizations indicate that the CM adsorbent was of cubic shape, uniformity in distribution with less agglomeration. The higher crystalline nature and the average particle size of 24 nm were characterized and the magnetization value of 14.46 emu g−1. An endeavor has been made to intend the batch sorption of Cr(VI) by CM magnetic adsorbent embracing Box-Behnken design strategy in response surface methodology (RSM). The most extreme Cr(VI) removal of 92.87 % was acquired at the initial Cr(VI) concentration of 94.5 mg L−1, the contact time of 66.2 min and the solution pH value of 5.5, and mechanical shaking of 200 rpm. The adsorption data for Cr(VI) onto CM adsorbent were well fitted with Langmuir isotherm and pursues the pseudo-second-order kinetics. The materialness of CM adsorbent to expel Cr(VI) from real water such as tested water, surface water, underground water, and tannery gushing water. The proficient recovery CM nano adsorbent was explored through group adsorption-desorption cyclic investigations. The profoundly crystalline CM nanoparticles have been demonstrated to be a promising adsorbent for Cr(VI) redemption from its aqueous mixture.

Preparation of an L-Cysteine Functionalized Magnetic Nanosorbent for the Sensitive Quantification of Heavy Metal Ions in Food by Graphite Furnace Atomic Absorption Spectrometry

A typical l-cysteine functionalized magnetic mesoporous nanosorbent (Cys–Si–MNPs) was successfully synthesized and characterized by transmission electron microscopy, the nitrogen adsorption–desorption isotherm and X-ray photoelectron spectroscopy. The results showed that Fe3O4 magnetic core was shelled by mesoporous silica, and the capacity of thiol group with strong affinity to various heavy metal ions was as high as 238 mg g−1. Using the obtained l-cysteine functionalized magnetic nanoparticles as the adsorbent, a graphite furnace atomic absorption spectrometry (GFAAS) method was developed for the determination of Pb2+, Cd2+, Cu2+, Cr3+, and V5+ in food. The experimental parameters affecting the separation performance including the pH of the sample solution, adsorbent mass, contact time, and co-existing ions were investigated systematically. Using the optimized conditions, the detection limits were as low as from 0.006 to 0.36 μg L−1. The precision of the method was evaluated by the relative standard deviation (n = 11) at limit of quantification (LOQ) of each target ion and was less than 6.0%. The proposed method was further successfully applied for the determination of the target ions in certified reference materials including GBW10043 rice, GBW 10023 laver, and GBW 10050 shrimp. The obtained recoveries were in the range from 89% to 102% with relative standard deviations (n = 3) lower than 8%.

Alginate-based magnetic nanosorbent immobilized with aptamer for selective and high adsorption of Hg2+ in water samples.

Alginate-coated magnetic nanocluster (MNC) immobilized with Hg2+-specific aptamer was synthesized to obtain the nanosorbent with high adsorption capacity and high selectivity for trace analysis of inorganic mercury (Hg2+) in water samples. Magnetite nanoparticle was first synthesized by a co-precipitation of iron precursors in the presence of alginate to obtain alginate-coated MNC, followed by immobilization with avidin. Hg2+-Specific DNA aptamer labeled with biotin was then conjugated on the MNC surface via specific avidin-biotin interaction to form aptamer-immobilized MNC. Coating the MNC with alginate can improve its water dispersibility and also increase its adsorption capacity toward Hg2+ (350mg/g). It exhibited high selectivity through thymine-Hg2+-thymine (T-Hg2+-T) interaction with high tolerance to other foreign ions. This nanosorbent showed linearity over the Hg2+ concentration range of 0.2-10μg/L with a correlation coefficient of 0.9977, limit of detection of 0.46μg/L, and enrichment factor of 13. Moreover, it also showed a potential for detection of Hg2+ in drinking and tap water samples with satisfactory recoveries.

An integrated approach for trace detection of pollutants in water using polyelectrolyte functionalized magneto-plasmonic nanosorbents

Resistance of pathogenic micro-organisms to conventional antibiotics is an essential issue for public health. The presence of such pharmaceuticals in aquatic ecosystems has been of major concern for which remediation and ultra-sensitive monitoring methods have been proposed. A less explored strategy involves the application of multifunctional nanosorbents for the uptake and subsequent detection of vestigial contaminants. In this study, colloidal nanoparticles (NPs) of iron oxide and gold were encapsulated in multi-layers of a charged polyelectrolyte (PEI: polyethyleneimine), envisaging the effective capture of tetracycline (TC) and its subsequent detection by Surface Enhanced Raman Scattering (SERS). Adsorption studies were performed by varying operational parameters, such as the solution pH and contact time, in order to evaluate the performance of the nanosorbents for the uptake of TC from water. While the magnetic nanosorbents with an external PEI layer (Fe3O4@PEI and Fe3O4@PEI-Au@PEI particles) have shown better uptake efficiency for TC, these materials showed less SERS sensitivity than the Fe3O4@PEI- Au nanosorbents, whose SERS sensitivity for TC in water has reached the limit of detection of 10 nM. Thus, this study highlights the potential of such magneto-plasmonic nanosorbents as multi-functional platforms for targeting specific contaminants in water, by taking into consideration both functionalities investigated: the removal by adsorption and the SERS detection across the nanosorbents’ surfaces.

Superparamagnetic nanosorbent for water purification: Assessment of the adsorptive removal of lead and methyl orange from aqueous solutions

The present study describes the preparation of 50.3 nm superparamagnetic nanosorbents with high surface area for the adsorptive removal of lead and methyl orange from water. This material is based on the surface modification of iron oxide superparamagnetic nanoparticles with a double-shell coating of mesoporous silica whose porosity was increased up to 570 m2/g by the addition of a porogenic material and its calcination. The adsorptive performance of the nanosorbent was evaluated as a function of several parameters (e.g. solution pH, pollutant initial concentration, and contact time), concluding that pHs around 5 are needed to avoid precipitation of Pb2+ as Pb(OH)2 and the equilibrium adsorption capacity is reached after 2 h in all cases. The experimental data on the adsorption capacity of lead and methyl orange onto the nanosorbent were fit to a pseudo-second order kinetic model and Langmuir isotherm model. The maximum adsorption capacity value increases from 35 up to 50 mg/gNS for lead removal with increasing nanosorbent surface area. Contrary, for methyl orange the maximum adsorption goes up to 240 mg/gNS, indicating a larger nanosorbent surface affinity for the organic matter that is able to diffuse through the silica pores as probed by the intraparticle diffusion model. In addition, we found an good reusability (100% recovering after 4 sorption/desorption cycles for methyl orange removal), which makes of this magnetic nanosorbent suitable for remediation technologies.

Efficient oil removal from wastewater based on polymer coated superhydrophobic tetrapodal magnetic nanocomposite adsorbent

We report the synthesis of an effective, biocompatible, magnetic nanosorbent polydimethylsiloxane@zinc oxide tetrapod@iron oxide nanorod nanohybrid using a hydrothermal process. The synthesized nanohybrid has been applied as a magnetic nanosorbent for oil removal from wastewater. The structural, chemical and magnetic characterizations of synthesized nanohybrid have been performed using X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller analysis and magnetization measurements using a superconducting quantum interference device. The prepared nanohybrid consists of ZnO tetrapods that are coated on the surface by Fe2O3 nanorods. The as-synthesized nanohybrid exhibits an exceptional adsorption ability and considerable magnetic separation due to its large surface area and high magnetic saturation value. The mechanism for the oil adsorption has been explicated by exploring different adsorption kinetics and isotherms models. It is inferred that this magnetic nanosorbent can be employed for effective oil removal from oily wastewater.

Magnetic nanosorbents with siliceous hybrid shells of alginic acid and carrageenan for removal of ciprofloxacin

Water contamination with antibiotics is a serious environmental threat. Ciprofloxacin (CIP) is one of the most frequently detected antibiotics in water. Herein, silica-based magnetic nanosorbents prepared using three seaweed polysaccharides, alginic acid, κ- and λ-carrageenan, were developed and evaluated in the uptake of ciprofloxacin. The sorbents were firstly characterized in detail to assess their morphology and composition. A systematic investigation was conducted to study the adsorption performance towards CIP, by varying the initial pH, contact time and initial CIP concentration. The maximum adsorption capacity was 464, 423 and 1350 mg/g for particles prepared from alginic acid, κ- and λ-carrageenan respectively. These high values indicate that these materials are among the most effective sorbents reported so far for the removal of CIP from water. The kinetic data were consistent with the pseudo-second-order model. The CIP adsorption on λ-carrageenan particles followed a cooperative process with sigmoidal isotherm that was described by the Dubinin-Radushkevich model. The high charge density of λ-carrageenan and the propensity of CIP molecules to self-aggregate may explain the cooperative nature of CIP adsorption. The sorbents were easily regenerated in mild conditions and could be reused in CIP removal up to 4 times without a significant loss of adsorptive properties.

Remediation of bio-refinery wastewater containing organic and inorganic toxic pollutants by adsorption onto chitosan-based magnetic nanosorbent

AbstractThe novelty of the current study deals with the application of magnetic nanosorbent, chitosan-coated magnetic nanoparticles (cMNPs), to be utilized for the management of lignocellulosic bio-refinery wastewater (LBW) containing three heavy metals and 26 phenolic compounds. The magnetic property of the adsorbent, confirmed by elemental and vibrating sample magnetometer analysis (saturation magnetization of 26.96 emu/g), allows easy separation of the particles in the presence of an external magnetic field. At pH 6.0, with optimized adsorbent dosage of 2.0 g/L and 90 min contact time, maximum removal of phenol (46.2%), copper (42.2%), chromium (18.7%) and arsenic (2.44%) was observed. The extent of removal of phenolic compounds was in the order: polysubstituted &amp;gt; di-substituted &amp;gt; mono-substituted &amp;gt; cresol &amp;gt; phenol. Overall, the adsorption capacity (qe) of cMNPs varies among the different contaminants in the following manner: copper (1.03 mg/g), chromium (0.20 mg/g), arsenic (0.04 mg/g) and phenol (0.56 mg/g). Post-adsorption, retrieving the cMNPs using an external magnetic field followed by single-step desorption via acid–base treatment is attractive for implementation in industrial settings. Reusability of the adsorbent was studied by recycling the cMNPs for five consecutive rounds of adsorption followed by desorption, at the end of which, cMNPs retained 20% of their initial adsorption capacity.