Magnetic Adsorbent Research Articles

Adsorption of Heavy Metal Ions on Alginate-Based Magnetic Nanocomposite Adsorbent Beads.

Graphene oxide and its magnetic nanoparticle-based composites are a well-known tool to remove heavy metals from wastewater. Unfortunately, one of the major issues in handling such small particles consists of their difficult removal from treated wastewater (even when their magnetic properties are exploited), due to their very small diameter. One possible way to overcome this problem is to embed them in a macroscopic biopolymer matrix, such as alginate or chitosan beads. In this way, the adsorbent becomes easier to handle and can be used to build, for example, a packed column, as in a traditional industrial adsorber. In this work, the removal performances of two different embedded magnetic nanocomposite adsorbents (MNAs) are discussed. The first type of MNA is based on ferrite magnetic nanoparticles (MNPs) generated by coprecipitation using iron(II/III) salts and ammonium hydroxide, while the second is based on a 2D material composed of MNP-decorated graphene oxide. Both MNAs were embedded in cross-linked alginate beads and used to treat artificial water contaminated with chromium(III), nickel(II), and copper(II) in different concentrations. The yield of removal and differences between MNAs and non-embedded magnetic nanomaterials are also discussed. From the results, it was found that the time to reach the adsorption equilibrium is higher when compared to that of the nanomaterials only, due to the lower surface/volume ratio of the beads, but the adsorption capacity is higher, due to the additional interaction with alginate.

MnFe2O4-NH2-HKUST-1, MOF magnetic composite, as a novel sorbent for efficient dye removal: fabrication, characterization and isotherm studies

Dye in industrial wastewater is one of the most serious environmental concerns due to its potentially harmful effects on human health. Many industrial dyes are carcinogenic, toxic and teratogenic. Removal and recovery of hazardous dyes from the effluents requires efficient adsorbents. In this study, magnetic adsorbent MnFe2O4-NH2-HKUST-1 was synthesized to remove methylene blue and crystal violet dyes from aqueous solutions. The synthesized adsorbent was characterized using FTIR, XRD, BET, VSM, SEM, TGA and Zeta potential techniques. The effect of different parameters such as pH, contact time, and adsorbent dosage on the removal of dyes was investigated. The dye adsorption process was investigated by UV–Vis spectrophotometry. The maximum adsorbent capacity was obtained as 149.25 mg/g for methylene blue and 135.13 mg/g for crystal violet. The adsorption equilibrium isotherm and kinetic models were plotted and results showed that the adsorption process for both dyes is a collection of physical and chemical adsorption based on langmuir and freundlich isotherm models, and follows the pseudo-second-order adsorption kinetics. This study shows that magnetic adsorbent MnFe2O4-NH2-HKUST-1 has a good potential for removal of methylene blue and crystal violet dyes from water in a short time (5 min) and it is easily separated from the solution by a magnetic field due to its magnetic property.

Efficient magnetic solid-phase extraction, UPLC-MS/MS detection, and consumption assessment of five trace psychoactive substances.

Wastewater-based epidemiology (WBE) has become an objective and updated surveillance strategy for monitoring and estimating consumption trends of psychoactive substances (PSs) in the population. Firstly, magnetic shrimp shell biochar-based adsorbent (DZMBC) was synthesized and employed for extraction trace PSs from municipal wastewater. Proper pyrolysis temperature and increased KOH activator content favored the pore structure and surface area, thus facilitating extraction. DZMBC delivered exceptional extraction performance such as pH stability, anti-interference property, fast magnetic separation ability, reusability, and reproducibility. Then, a method based on magnetic solid-phase extraction (MSPE) followed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed, validated, and utilized for the quantitative determination of five PSs in real wastewater samples. Methodological validation results indicated a favorable linearity, low method limits of detection (1.00-4.75ng/L), and good precisions (intra-day and inter-day relative standard deviations < 4.8%). Finally, an objective snapshot of Chongqing drug use and consumption pattern was obtained. Methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA) were the prevalent illegal drugs in local. Both concentrations and per capita consumption of MDMA displayed a change (P < 0.05) between July and September, while no statistical differences were observed for each week.

Metronidazole adsorption by bio-synthesized silver-zinc ferrite nanoadsorbent in presence of chitosan from aqueous media: response surface methodology

A novel magnetic biocomposite adsorbent, denoted as AgZnFe2O4@Ch, was utilized for the degradation of Metronidazole (MNZ) from water. Various analytical techniques, including vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Brunauer–Emmett–Teller, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy (FESEM), were applied to investigate the characteristics of the magnetic biocomposite adsorbent. XRD examination confirmed the formation of spinel ferrites phases. FESEM assessment indicated a notable reduction in sample aggregation. The ferromagnetic character of the adsorbent was well demonstrated by VSM analysis. The saturation magnetization value for straightforward separating by the outside magnetic fields was 14.64 emu/g. An analytical modeling approach was used to evaluate and analyze the impacts of factors including MNZ initial concentration, temperature, contact time, adsorbent dosage, and pH. Optimized conditions involved an adsorbent dosage of 0.9 g/L, pH of 7, MNZ initial concentration of 10 mg/L, and a contact time of 50 min, resulting in a peak adsorption efficiency of 65.53% under favorable circumstances. A good degree of fit was achieved with the linear model. The experimental equilibrium data fitting to the Langmuir, Freundlich, and Temkin isotherm models demonstrates that the Langmuir model was an effective and appropriate model for evaluating adsorption. Intraparticle kinetic modeling was also shown to be better suitable for characterizing the MNZ adsorption onto the adsorbent. The thermodynamic analysis indicated that the process of MNZ adsorption by AgZnFe2O4@Ch was characterized by exothermicity and lacked spontaneity.

The Selective Removal of Bisphenol A Using a Magnetic Adsorbent Fused with Bisphenol A-Binding Peptides.

The potential of bisphenol A (BPA)-binding peptides fused to magnetic beads is demonstrated as novel adsorbents that are reusable and highly selective for BPA removal from aqueous environments, in which various interfering substances coexist. Magnetic beads harboring peptides (peptide beads) showed a higher BPA removal capacity (8.6 mg/g) than that of bare beads without peptides (2.0 mg/g). The BPA adsorption capacity of peptide beads increased with the number of peptides fused onto the beads, where monomeric, dimeric, or trimeric repeats of a BPA-binding peptide were fused to magnetic beads. The BPA-adsorbing beads were regenerated using a methanol-acetic acid mixture, and after six regeneration cycles, the adsorption capacity remained above 87% of its initial capacity. The selective removal of BPA was confirmed in the presence of BPA analogs with high structural similarity (bisphenol F and bisphenol S) or in synthetic wastewater. The present work is a pioneering study that investigates the selective affinity of peptides to remove specific organics with high selectivity from complex environmental matrices.

Portable mass spectrometer with solid phase extraction using a novel amide-functionalized magnetic covalent organic framework adsorbent for on-site detection of two triphenylmethane dyes in aquatic products

Triphenylmethane dyes have been employed as fish drugs to prevent fish diseases for aquatic products in some developing countries. Their residues in aquatic products can bring significant impact on human health. In this study, an amide-functionalized magnetic covalent organic framework assisted magnetic solid phase extraction-portable mass spectrometry (MSPE-PMS) strategy was employed for on-site simultaneous detection of cationic triphenylmethane dyes, crystalline violet (CV) and brilliant green (BG). At the optimum MSPE conditions, the adsorbent was used to efficiently enrich CV and BG through magnetic solid phase extraction within 20 min with satisfied high concentration rate (10 folds). Then, the portable mass spectrometer was employed for simultaneous detection CV and BG within 0.2 min, with good linearity (R2 ≥ 0.9973) and low detection limit (0.135–0.694 μg kg−1). The results demonstrated the method is fast and simple and has the potential to detect triphenylmethane dyes residues in aquatic products quickly and on site.

Molecular insights into the simultaneous removal mechanisms of As(Ⅴ) and Cd(II) in iron tailings slag-biochar composites

Arsenic and cadmium contamination frequently coexist in the real environment. However, it remains a challenge for their simultaneous removal due to their distinct physicochemical properties at low cost. To this end, a cost-effective magnetic biochar adsorbent (ITBNa800) was prepared using biomass waste and iron tailings slag. This composite adsorbent exhibits excellent performance in the simultaneous removal of aqueous As(V) and Cd(II) even at high concentrations with removal efficiencies of up to 99.98% and 96.04%, respectively. Electrostatic action, precipitation, and complexation were adsorption mechanisms. As(V) and Cd(II) were synergistic and competitive adsorption. As(V) removal was mainly due to physical and chemical adsorption, and 42.40%-58.59% of As(V) had been converted to As(III). Cd(II) removal was mainly due to chemical adsorption. Iron oxide and aluminum oxide in ITBNa800 were the keys to As(V), As(III), and Cd(II) adsorption. DFT calculations revealed iron oxide complex As(V), As(III), and Cd(II) molecular clusters through bidentate binuclear, bidentate binuclear, and monodentate binuclear pathways, respectively. Aluminum oxide complex Cd(II) molecular cluster through a bidentate mononuclear pathway. We hope the ITBNa800 adsorbent and its involved mechanism could offer inspiration in the simultaneous treatment of As and Cd pollution.

Magnetic and PEG-crosslinked poly(methyl acrylate) functionalized with triethylenetetramine for removal of lead ions from contaminated water

A new magnetic polymer adsorbent with high swellability was prepared based on a PEG-crosslinked poly(methyl acrylate) via ATRP technique. FT-IR, TGA, CHN, FE-SEM, EDX, XRD, VSM, BET, and DLS measurements were used for the characterization of the prepared adsorbent. After replacing terminal bromines with triethylenetetramine chelating agent, the adsorption process of lead ions led to the removal of these ions from aqueous solutions. The removal of lead ions was investigated using ICP-OES technique. At pH = 7, the equilibrium adsorption capacity increased significantly and reached 37 mg/g at a contact time of 60 min. The adsorption capacity increased with increasing adsorption temperature (up to 40 °C) and initial concentration of lead ions (up to 70 mg/L), while it decreased with increasing adsorbent dose. The Freundlich isotherm better described the process of adsorption of lead ions by the prepared adsorbent. The adsorption kinetic was in greater agreement with pseudo-second-order model. The prepared adsorbent performed much better in adsorbing lead ions compared to cobalt and mercury ions. By performing the adsorption–desorption process three times, it was found that the adsorbent has high reusability. Overall, high swelling behavior and ease of magnetizability are two prominent features of the newly prepared adsorbent.

Advancing cobalt ferrite-supported activated carbon from orange peels for real pulp and paper mill wastewater treatment

The utilization of agriculture waste-based adsorbents in the treatment of real industrial wastewater represents an unexplored frontier with significant potential. In this study, the cobalt ferrite-supported activated carbon derived from orange peels (CF40-AC) was used as a magnetic adsorbent for the treatment of real pulp and paper mill effluent (PPME). Detailed insights into the properties and functionalities of the CoFe2O4-AC adsorbent were obtained through an accurate characterization analysis that included X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), BET and pore size histogram techniques. Both pure activated carbon (AC) and CF40-AC displayed excellent textural properties with surface area (SBET) equal 2014 and 1345 m2.g−1, respectively. TEM and SEM images display that the magnetic ferrites were well dispersed on the surface of AC. Following the characterization process, the CoFe2O4-AC adsorbent was evaluated for its ability to remove several key pollutants from PPME, including chemical oxygen demand (COD), total dissolved solids (TDS) and turbidity. Moreover, various operational parameters, such as pH, adsorbent dosage, contact time, and stirring rate, were investigated to achieve optimal contaminants removal rates. Remarkably, the CoFe2O4-AC adsorbent demonstrated highly efficient removal rates, with 86.9%, 59,9% and 93.1% for COD, TDS and turbidity, respectively, under optimal conditions (pH 7, adsorbent dose 0.4 gm, contact time 60 min, and stirring rate 150 rpm). The CoFe2O4-AC composite material exhibits promising potential for multiple applications reached 5 cycles without a significant loss in its adsorption or functional properties over successive uses. These results favor the promising potential of CoFe2O4-AC as a sustainable and efficient solution for addressing wastewater treatment challenges in the pulp and paper industry, contributing to both environmental protection and resource conservation.

Use of Fe-Mn magnetic adsorbent to remove mercury from wastewater

In this work, Fe-Mn magnetic adsorbent was used to remove mercury from wastewater. This research characterizes the structural properties of the adsorbent and also investigates the effects of the operating conditions to evaluate the adsorbent effectiveness for water treatment applications. In the adsorbent preparation stage, the MnCl2 concentration in the solution was chosen at 0.03 mol/L to synthesize the best adsorbent. The structural properties of the Fe-Mn magnetic adsorbent were examined through SEM, ICP, FTIR, XRD, and VSM analyses. XRD results confirmed the presence of FeMnO4 and Fe3O4. VSM showed the superparamagnetic properties of the adsorbent. The influences of the solution pH, Hg (II) initial concentration, adsorption time, and adsorbent dose were explored. The mercury removal of 99% occurred at 30 min, Hg (II) initial concentration 42 mg/L, pH 6, and adsorbent dose of 4.4 g/L. The pseudo-second order kinetic fitted better to the experimental data. The Langmuir isotherm also suitably corresponded to the data. The maximum Hg (II) adsorption capacity of Fe-Mn magnetic adsorbent was 5.408 mg/g. The positive changes of the Gibbs free energy indicated that the adsorption process was endothermic and spontaneous. Overall, Fe-Mn magnetic adsorbent exhibits commendable performance in removing mercury from wastewater.

Pemanfaatan Magnetic Biochar dari Cangkang Sawit Sebagai Adsorben untuk Menyisihkan COD, Total Suspended Solid, Minyak dan Lemak dalam Air Buangan Domestik

Greywater is wastewater from domestic activities sourced from kitchens, bathrooms, and laundry water. Greywater discharged directly into the environment can cause a decrease in surface water quality due to its high organic content, nutrients, pathogenic bacteria, and detergents and surfactants. One method that can be used to remove organic and nutrient content is adsorption. The success of the adsorption process is determined by several factors, such as adsorbent type, dosage, contact time, and others. One adsorbent that has attracted the attention of many researchers in recent years is magnetic biochar. This study aims to remove chemical oxygen demand (COD), total suspended solids (TSS), oil, and grease from greywater with a magnetic biochar adsorbent made from palm shells. The study was conducted by varying the dose of 1.2–8.55 g/l and the contact time of 30–150 minutes. The results showed that increasing the dose and contact time can increase the removal efficiency of COD, TSS, oil, and grease. The best results were obtained at a dose of 8.55 g/l and a contact time of 150 minutes. The removal of COD, TSS, oil, and grease was 87.91%, 88.46%, and 99.96%, respectively.

Pemanfaatan Lumpur Lapindo sebagai Sumber Silika Magnetik untuk Adsorpsi Tumpahan Crude Palm Oil

In this paper, synthesis of silica magnetite adsorbent has been carried out from Lapindo Mud silica and magnetite (Fe3O4) using the template Cetyltrimethylammonium bromide (CTAB) through a microemulsion process. This research aims to determine the adsorption ability of magnetic silica material as an adsorbent for Crude Palm Oil (CPO) with varying contact times of 10, 20, 30, 60, 90 minutes and an adsorbate concentration of 0,2, 0,4, 0,6, 0,8 and 1 gram. Silica is obtained from Lapindo Mud extraction using the acid leaching method using HCl. Magnetite was prepared by mixing ferric chloride and ferrous chloride salts with an alkaline base. Synthesis of magnetic silica adsorbent using CTAB and 1-butanol as a surfactant and co-surfactant, respectively. The characterization results from FTIR and SEM-EDX data identified the presence of silanol (Si-OH) and Fe-O groups, magnetic silica adsorbent showed an irregular morphological pattern, the size tended to be heterogeneous, contained Fe, O and Si elements. The XRD results show that there are peaks in the (200), (311) and (440) planes, the GSA results show that the pore surface area is 37.048 m2/g, the total pore volume is 0.321 cm3/g and the pore diameter is 33.907 nm, which indicates that the pores have a mesoporous structure. Based on this research, the optimum contact time is 60 minutes with adsorption kinetics following the pseudo-second order and Langmuir isotherm with an adsorption capacity of 1.76 mg/g.

Ultrafast and highly efficient Cd(II) and Pb(II) removal by magnetic adsorbents derived from gypsum and corncob: Performances and mechanisms

The utilization of gypsum and biomass in environmental remediation has become a novel approach to promote waste recycling. Generally, raw waste materials exhibit limited adsorption capacity for heavy metal ions (HMIs) and often result in poor solid–liquid separation. In this study, through co-pyrolysis with corncob waste, titanium gypsum (TiG) was transformed into magnetic adsorbents (GCx, where x denotes the proportion of corncob in the gypsum–corncob mixture) for the removal of Cd(II) and Pb(II). GC10, the optimal adsorbent, which was composed primarily of anhydrite, calcium sulfide, and magnetic Fe3O4, exhibited significantly faster adsorption kinetics (rate constant k1 was 218 times and 9 times of raw TiG for Cd(II) and Pb(II)) and higher adsorption capacity (Qe exceeded 200 mg/g for Cd(II) and 400 mg/g for Pb(II)) than raw TiG and previous adsorbents. Cd(II) removal was more profoundly inhibited in a Cd(II) + Pb(II) binary system, suggesting that GC10 showed better selectivity for Pb(II). Moreover, GC10 could be easily separated from purified water for further recovery, due to its high saturation magnetization value (6.3 emu/g). The superior removal capabilities of GC10 were due to adsorption and surface precipitation of metal sulfides and metal sulfates on the adsorbent surface. Overall, these waste-derived magnetic adsorbents provide a novel and sustainable approach to waste recycling and the deep purification of multiple HMIs.

Efficient removal of Congo Red by carbonized Ganoderma lucidum spore with Fe3O4

In this study, a biomass carbon magnetic adsorbent (Fe3O4@GLSM) was prepared by using carbonized G. lucidum spores and Fe3O4 nanoparticles. Scanning and transmission electron microscopy proved that the G. lucidum spores after carbonization (GLSM) have hollow cage structure and increased surface depression. X-ray diffraction, X-ray photoelectron spectroscopy, and vibrating sample magnetometer analysis demonstrated that magnetic Fe3O4 nanoparticles were successfully loaded on GLSM. We have investigated the affective adsorption factors of contact time, pH, and adsorbent dose on the adsorption properties of CR from aqueous solution. Adsorption process is less affected by acidity and alkalinity and can reach to adsorption equilibrium. The maximum Fe3O4@GLSM adsorption capacity is 58.4 mg. The kinetic data for the adsorption of CR were well fitted by the pseudo-second-order kinetic equation. The intra-particle diffusion model showed that the adsorption involved surface adsorption followed by diffusion. Freundlich isotherm models provided a more accurate representation of sorption isotherms than Langmuir model. The adsorption thermodynamics (ΔGθ, ΔHθ and ΔSθ) established that CR adsorption onto Fe3O4@GLSM was spontaneous and feasible. This novel magnetic biomass adsorbent can potentially serve as an effective method for removing and rapidly separating pollutants in wastewater treatment.

Facile synthesis of novel hexagonal strontium ferrites for promising adsorption of cadmium from aqueous solutions

Cadmium (Cd(II)) contamination in both the surface and ground water is threatening the lives of millions of people across the world. In this work, we have hydrothermally synthesized the novel multiphase (MP) and single phase (SP) M-type hexagonal strontium ferrites (SF, SrFe12O19) for removing Cd(II) from contaminated water. The as-synthesized materials were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform Infrared spectroscopy (FTIR) and X-ray photoelectron spectrometry (XPS). The MP-SF and SP-SF demonstrated excellent Cd(II) adsorption capacities over wide pH range. The pseudo-first and second-order kinetics models as well as the Langmuir and Freundlich isotherms models were used for fitting the experimental data for adsorption of Cd(II) on both the MP-SF and SP-SF. The maximum adsorption capacities reached to 57.5 and 78.9 mg/g for the MP-SF and SP-SF, respectively, at pH 7, which were better than many recently reported magnetic adsorbents. The effects of common co-existing ions on the adsorption capacities of both the MP-SF and SP-SF were also evaluated. FTIR and XPS spectroscopic analyses further confirmed that Cd(II) was adsorbed on to the surface of SP-SF through the formation of an inner-sphere complex between the Cd(II) and surface metal centers.Furthermore, the as-synthesized materials were employed for the treatment of simulated real Cd(II) contaminated water. The experimental results suggested that the SP-SF could be a strong candidate for practical applications of Cd(II) removal from aqueous solutions.

Efficient removal of tetracycline and Cu2+ by honeycomb derived magnetic carbon: Adsorption mechanism and advanced oxidation regeneration mechanism

The honeycomb magnetic carbons (xFe@HCNs) were prepared by sacrificial template method novelty using polyacrylamide resin (PAAS) as template and ammonium pyrrolidine dithioate/Fe3+ complex (APDC-Fe) as carbon skeleton and metal source. Tetracycline (TC) and copper (Cu2+) as target pollutants were used to investigate the adsorption properties of xFe@HCNs in single or binary TC and Cu2+ systems. The adsorption capacity sequence for TC among the adsorbents was (mmol·g−1): 2Fe@HCNs (0.088) > 8Fe@HCNs (0.061) > HCNs (0.054) > RC (0.036), and for Cu2+ was (mmol·g−1): 2Fe@HCNs (1.120) > 8Fe@HCNs (1.026) > RC (0.792) > HCNs (0.681). 2Fe@HCNs demonstrated notable affinity for adsorbing both TC and Cu2+. Additionally, the influence of hydrochemical factors (i.e., cation species, anion species, and pH) on the adsorption properties of 2Fe@HCNs. Combined with advanced oxidation technology, the regeneration methods of magnetic adsorbent were explored using oxidizing agents (e.g., H2O2 and peroxymonosulfate) as eluents which could increase the adsorption sites of magnetic carbon adsorbents during the regenerating process, which was the novelty of the study. Furthermore, the regeneration mechanisms of H2O2 as eluent were investigated. This study discussed the application and regeneration methods of magnetic adsorbents in water treatment, offering new insights into environmental remediation using magnetic materials.

Magnetic Solid-Phase Extraction (MSPE) Coupled With Gas Chromatography-Barrier Discharge Ionization Detection (GC-BID) for the Simultaneous Determination of 16 Phthalates in Baijiu

Prolonged exposure to phthalates (PAEs) can adversely affect the human endocrine system. This study proposes a method for quantitatively determining the PAE content in Baijiu using magnetic solid-phase extraction (MSPE) coupled with gas chromatography-barrier discharge ionization detection (GC-BID). A hydrophobic reversed-phase (C18) magnetic adsorbent was used to extract and enrich the PAEs in Baijiu, and GC-BID was used for their separation and detection. The pretreatment and detection conditions were investigated and optimized to improve the recovery of the PAEs. Under the optimized conditions, the method performed effectively in the linear range (20.0–3000.0 ng/mL), with limits of detection ranging from 0.04 to 0.62 ng/mL, relative standard deviations from 1.5 to 8.7% and enrichment factors from 26.6 to 50.0. The MSPE-GC-BID method successfully detected PAEs in the Baijiu samples. The recovery of the 16 PAEs in the spiked Baijiu ranged from 42.3 to 143.9%, with a relative standard deviation of less than 7.2%. This method shows good repeatability and precision, making it suitable for the determination of phthalates in Baijiu.

Rapidly enrichment and detection of per-and polyfluoroalkyl substances in foods using a novel bifunctional covalent organic framework

Per- and polyfluoroalkyl substances (PFASs) are extensively found in foods, posing potential toxicity to humans. Therefore, rapid analysis and monitoring of PFASs in foods are crucial for public health and also a challenge. To detect trace PFASs in foods, construction of sorbents with multiple interactions could be an effective approach. Herein, a cationic-fluorinated covalent organic framework (CF-COF) was prepared by post-modification and used as a magnetic solid-phase extraction adsorbent for adsorption of PFASs. By combining magnetic solid-phase extraction based on CF-COF with liquid chromatography−tandem mass spectrometry (LC − MS/MS), a novel method was developed for determination of eight long-chain PFASs in foods. Under optimized conditions, the method exhibited low detection limits (0.003–0.019 ng/g) and satisfactory recovery rates (73.5–118%) for PFASs. This study introduces a novel idea for the development of adsorbents targeting PFASs, along with a new analytical method for monitoring of PFASs in foods.

Functional upcycling of waste PET plastic to the hybrid magnetic microparticles adsorbent for cesium removal

Accumulation of mismanaged plastic in the environment and the appearance of emerging plastic-derived pollutants such as microplastics strongly demand technologies for waste plastic utilization. In this study, polyethylene terephthalate (PET) from waste plastic bottles was directly utilized to prepare a matrix of an adsorbent for cesium (Cs+) removal. The organic matrix of PET-derived oligomers obtained by aminolysis depolymerization was impregnated with bentonite clay and magnetite nanoparticles (Fe3O4 NPs), playing the roles as a major adsorptive medium for Cs+ removal and as a functional component to primarily provide efficient separation of the hybrid adsorbent from aqueous system, respectively. The obtained hybrid composite microparticles were next tested as an adsorbent for the removal of Cs+ cation from aqueous solutions. The adsorption process was characterized by fast kinetics reaching ca. 60% of the equilibrium adsorption capacity within 5 min and the maximum adsorption capacity toward Cs+ was found to be 26.8 mg/g. The adsorption process was primarily dominated by the cationic exchange in bentonite, which was not significantly affected by the admixture of the competing mono- and divalent cations (Na+, K+, and Mg2+). The proposed approach here exploits the sustainable utilization scenario of plastic waste-derived material to template complex multifunctional nanocomposites that can find applications for pollution cleaning and environmental remediation.

Highly effective and reusable Ni–Al oxide/Zn0.4Co0.6Fe2O4 superparamagnetic aerogel for oil-water separation

Oily wastewater from the oil industry and oil spill accidents has become a serious environmental problem and has attracted worldwide attention. The present study reports on the successful preparation of a novel magnetic Ni–Al oxide/Zn0.4Co0.6F2O4 mesoporous aerogel (MNA) as a highly selective adsorbent for oil removal from water. Oleic acid (OA) and Triton X-100 (TX) were used as hydrophobic agents for MNA surface modification. It was found that the attached amount of OA on the mesoporous MNA aerogel is 3.5 times larger than that of TX, giving an advantage to MNA-OA in oil separation. The MNA-OA displayed superhydrophobicity (contact angle ∼150°) and superparamagnetism properties that allowed the adsorbent to be used selectively for oil removal. The MNA-OA was found to have a high oil removal efficiency of ∼97% with an adsorption capacity of ∼2 g/g. Furthermore, the produced magnetic adsorbent has high stability due to the strong chemical binding of OA, which is demonstrated by its good reusability performance. Throughout five separate runs, the MNA-OA was shown to be a very efficient and reusable adsorbent for oily wastewater.