Nanocomposite Beads Research Articles

Effect of Structurally Different Magnetic Alginate Nanocomposite Beads on Fenton-Like Oxidation of Direct Dyes

Effect of Structurally Different Magnetic Alginate Nanocomposite Beads on Fenton-Like Oxidation of Direct Dyes

Efficient multifunctional PPy-NTs/PEI@alginate@NiFe2O4 magnetic beads for heavy metals removal: Experimental design and optimization interpretations

A highly effective magnetic nanocomposite alginate beads (PPy-NTs/PEI@Alg@NiFe2O4) were synthesized using alginate as the encapsulation reagent and polypyrrole/polyethylene imine with nano NiFe2O4 as a functional filler to remove toxic Zn2+ and Pb2+ from polluted water. A response surface methodology (RSM) was used to statistically assess the influences of pH and the adsorbent dose on the adsorption performance. PPy-NTs/PEI@Alg@NiFe2O4 magnetic microbeads exhibited the optimal adsorption capacity qe (18.6 mg/g) at pH 6 and a 2 mg/L dose for Zn2+ removal. In comparison, the optimal qe (32.6 mg/g) was reached at pH 4.5 with a 1.5 mg/L dose for Pb2+ remediation. From batch experiments, maximal absorption capacities of 53.3 mg/g and 22 mg/g were achieved for Pb2+ and Zn2+, respectively, at 313 K. The pseudo-second-order kinetic model fitted the results well, suggesting that the chemisorption process regulates adsorption. Isotherm models indicate the presence of homogeneous adsorption sites from the well-fitting to Langmuir isotherm. An investigation of the effects of temperature and thermodynamic considerations revealed the endothermic nature of Zn2+ and Pb2+ absorption. The Fourier transform infrared spectra showed that –NH, –NH2, and –COO− are the main groups in PPy-NTs/PEI@Alg@NiFe2O4 composite beads that were responsible for Zn2+ and Pb2+ removal from polluted water.

Removal of phosphate from wastewater using zirconium/iron embedded chitosan/alginate hydrogel beads: An experimental and computational perspective

Adsorptive removal of phosphate plays a crucial role in mitigating eutrophication. Herein, the Zr/Fe embedded chitosan/alginate hydrogel bead (Zr/Fe/CS/Alg) is reported as an effective phosphate adsorbent. This polymer nanocomposite is synthesized by the in-situ reduction of the metals on the polymer matrix. The synthesized adsorbent was characterized by the FTIR, SEM-EDX, TGA, BET, and XPS. The adsorbent showed a maximum phosphate adsorption capacity of 221.72 mg/g at pH 3. The experimental data fit well with the Freundlich isotherm and pseudo-second-order kinetics model, indicating a heterogeneous multilayer surface formation and a chemisorption-dominated adsorption process. Density Functional Theory (DFT) and Monte Carlo (MC) calculations revealed high negative adsorption energy due to the chemisorption of phosphate on the adsorbent. Hence, the major interactions such as electrostatic attraction, hydrogen bonding, and inner-sphere complexation of phosphate adsorption and Zr/Fe/CS/Alg hydrogel beads were investigated from the experimental and computational analysis. The negative values of thermodynamic parameters indicated a spontaneous, exothermic, and less random adsorption process. The synthesized adsorbent exhibited excellent selectivity toward phosphate and maintained 73 % efficiency after six adsorption/desorption cycles. The Zr/Fe/CS/Alg hydrogel beads reduced the phosphate concentration in real wastewater samples from 19.02 mg/L to 0.985 mg/L, suggesting that these nanocomposite hydrogel beads could be a promising adsorbent for real-world applications.

Design of Recyclable Adsorbent for Water Pollutants Based on Chitosan-Coated Carboxymethyl Cellulose-Calcium Alginate Wrapped Iron Oxide-Copper Oxide Composite Beads

ABSTRACT In this study, an efficient nanocomposite based on calcium alginate-carboxymethyl cellulose/iron oxide-copper oxide (CA-CMC/Fe2O3-CuO) is developed in beads form and utilized as nanoadsorbent and nanocatalyst. Further, the beads were coated with chitosan, resulting in Cs@CA-CMC/Fe2O3-CuO beads. The prepared beads exhibited exceptional adsorption capabilities for selected heavy metal ions. Notably, the Cs@CA-CMC/Fe2O3-CuO beads displayed remarkable adsorption among the other beads toward the three selected metal ions. Ag(I) was highly adsorbed by Cs@CA-CMC/Fe2O3-CuO beads, and the adsorption capacity of beads was 4.91 mgg−1, while 4.5 mgg−1 and 3.0 mgg−1 for Co(II) and Ni(II), respectively. Beads’ ability to adsorb Ag(I) varied depending on several factors. It was observed that the adsorption capacity of Ag(I) ions increased as the interaction time and metal concentration rose. However, increasing the beads dose led to a decrease in the Ag(I) ion adsorption. Further, the waste beads after Ag(I) adsorption were treated with reducing agent to form beads supported Ag nanoparticles (Ag/Cs@CA-CMC/Fe2O3-CuO) and used as effective catalyst for reducing 4-nitrophenol in the presence of NaBH4 as a reducing agent. Ag/Cs@CA-CMC/Fe2O3-CuO achieved reduction up to 93% for 4-NP within 30 min. The designed nanocomposite beads displayed several desirable attributes, including eco-friendliness and robust catalytic performance, making them highly promising for useful reduction of 4-NP.

Investigation on ferrite immobilized alginate magnetic nanocomposite beads for the adsorptive removal of Prussian blue

This research article was investigates the Prussian blue dye removal from aqueous solution using immobilized nano ferrite (Zn-Co-Fe) in alginate biopolymer. The preparation of alginate beads was done by metal encapsulation method using CaSO4 as crosslinking agent. The Prussian blue dye removal efficiency was ascertained with various isotherm equations such as Langmuir and Freundlich. Isotherm equations are not providing physical, chemical and feasibility aspects. So, these were investigated with pseudo-first order, pseudo-second order kinetic equations. The mode of diffusion evaluated with intraparticle diffusion and thermodynamic feasibility was tested with the equations of enthalpy, Gibbs free energy, and entropy. The experimentally driven results were implies the Prussian blue removal process was feasible in all aspects. Moreover, the predicted diffusion parameters revealed that the interaction between Prussian blue and nanocomposite beads was predominant. The surface morphology, examined using a Scanning Electron Microscope, showed that the Prussian blue strongly covered on outer surface of the beads. The FTIR proves the Prussian blue dye was strappingly loaded on the surface of nanocomposite beads. The TGA curve revealed the synthesized beads has an exceptional temperature resistance.

Sodium alginate/banana peels/reduced graphene oxide nanocomposite beads for effective removal of copper and nickel from aqueous solutions

The use of naturally derived nanocomposite beads to remove nickel and copper is gaining more attention due to its relative abundance, low toxicity, and strong affinity toward heavy metals. Most previous studies focus on removing single heavy metals using developed nanocomposite beads. This work prepared sodium alginate/banana peels/reduced graphene oxide nanocomposite beads through simple precipitation using banana peels, reduced graphene oxide, and sodium alginate. The formed nanocomposite beads were characterized and evaluated for the adsorption of nickel and copper from the aqueous phase at neutral pH. The Langmuir isotherm suggests the homogenous adsorption of metals on the surface of the bead. The maximum removal capacity is 85.32 mg/g and 95.79 mg/g for nickel and copper, respectively. This study provides new insight into utilizing banana peels, reduced graphene oxide, and sodium alginate for toxic metal remediation to overcome pollution problems.

Design of biocompatible gelatin hydrogels reinforced with magnetite nanoparticles: Effective removal of chromium from water environment

The development of biocompatible adsorbents is vital for environmental remediation to control and reduce pollution and waste accumulation in ecosystems. Biocompatible hydrogels represent an innovative class of materials that are primarily composed of polymer chain units forming their structural framework. They have a high affinity for water molecules. This research thus aims to incorporate iron oxide particles into the gelatin matrix to produce gelatin hydrogel beads to remove hexavalent chromium from an aqueous solution. The synthesized beads, known for their consistent size, low friction, high specific surface area, mechanical stability, and lightweight characteristics, demonstrated their suitability for various industrial applications. The effectiveness of these hydrogels in removing hexavalent chromium ions was confirmed through a thorough analysis using techniques such as FTIR, TGA, SEM, EDX, VSM, and XPS. Batch experiments revealed that the gelatin-based nanocomposite beads exhibited optimal adsorption efficiency under acidic conditions, lower initial concentrations of chromium ions, extended contact time, and elevated temperature (50–60 °C). The composite achieved a maximum removal efficiency of 99% at pH 1, with an adsorbent dose of 0.5 g at 50 °C, and an initial concentration of 50 mg per liter. The use of 0.7 N NaOH in the regeneration process resulted in a commendable 70.5% desorption efficiency, enabling potential reuse and regeneration. Significantly, the desorption efficiency remained consistently high even after four desorption-readsorption cycles, contributing to the economic and environmental sustainability of chromium removal. Additionally, the study determined that the sorption process was feasible, spontaneous, and endothermic. These collective findings suggest that magnetic gelatin hydrogel beads could serve as a cost-effective alternative adsorbent for the efficient removal of chromium ions from aqueous solutions.

Novel ternary nanocomposite (TiO2@Fe3O4-chitosan) system for nitrate removal from water: an adsorption cum photocatalytic approach.

Nitrate pollution of water emerging from various anthropogenic activities has become a major environmental concern because of its deleterious effects on natural water resources. The present work deals with the synthesis of the ternary nanocomposite based on chitosan, iron oxide (Fe3O4), and titanium dioxide (TiO2) and its application for the removal of nitrates from model-contaminated water. Fe3O4 derived through a coprecipitation method was incorporated into the chitosan matrix which was fabricated in the form of beads. The wet gel beads were then successfully coated with sol-gel-derived silver-doped titanium dioxide sol followed by drying under suitable conditions to get the functional nanocomposite beads. The synthesized functional materials were further characterized for their structural, morphological, and textural features using X-ray diffraction analysis, physical property measurement (PPMS), Fourier transform infrared (FTIR) analysis, UV visible spectroscopy analysis (UV-vis), BET surface area analysis (BET), field emission scanning electron microscopic (FESEM), and transmission electron microscopy (TEM) analysis. The ternary nanocomposites were further used for the removal of nitrates via adsorption cum photocatalytic reduction technique from the model contaminated water when subjected to an adsorption study under dark conditions and photocatalytic study under UV/visible/sunlight for a definite time. Fe3O4 in the nanocomposite provides enhanced adsorption features whereas the functional coating of titanium dioxide aids in the removal of nitrates through the photocatalytic reduction technique. The functional beads containing 3% Fe3O4 in the wet gel form (CTA-F3) have excellent nitrate removal efficiency of ~ 97% via adsorption cum solar photocatalysis towards the removal of nitrate ions from 50ppm nitrate solution, whereas the dried nanocomposite beads have got a nitrate removal efficiency of ~ 68% in 1h from 100ppm nitrate solution. Continuous flow adsorption cum photocatalytic study was performed further using the oven-dried functional beads in which flow rate and bed height were varied while maintaining the concentration of feed solution as constant. A nitrate removal efficiency of 65% and an adsorption capacity of 4.1 mgg-1 were obtained for the CTA-F3 beads in the continuous flow adsorption cum photocatalysis experiment for up to 5h when using an inlet concentration of 100ppm, bed height 12cm, and flow rate 5.0mlmin-1. A representative fixed-bed column adsorption experiment conducted using CTA-F3 beads for the treatment of a real groundwater sample shows reasonable results for nitrate removal (71.7% efficiency) along with a significant removal rate for the other anions as well. Thus, the novel adsorbent/photocatalyst developed is suitable for the removal of nitrates from water due to the synergistic effect between Fe3O4, chitosan, and titanium dioxide.

Ajwa date seed mediated green synthesis of alginate-silver nanocomposite beads and films for antibacterial and catalytic degradation applications

Ajwa date seed mediated green synthesis of alginate-silver nanocomposite beads and films for antibacterial and catalytic degradation applications

Bioremediation of crude oil polluted surface water using specialised alginate-based nanocomposite beads loaded with hydrocarbon-degrading bacteria and inorganic nutrients

This study explored the elimination of petroleum from river water using matrix-bound composites of iron oxide nanoparticles (IONPs) decorated on biochar with immobilized hydrocarbon-degrading bacteria (HCB) and monoammonium phosphate (MAP) at 10%v/v pollution levels. The beads containing biochar and IONPs (BCNP) showed better pollutant removal than those with biochar alone (BC). The treatment with beads containing biochar, IONPs, HCB and MAP had the highest removal efficiency for TPH (98.5%) and PAH (93.7%) and the lowest biodegradation half-lives. The removal efficiency for TPH and PAH was greater in the treatment microcosms than in the controls with significant differences (p ≤ 0.05) between the two groups. TPH and PAH elimination levels differed significantly (p ≤ 0.05) between systems with the BC bead and those with the BCNP beads. The study revealed a steady increase in the abundance of the total cultivable heterotrophic bacteria and cultivable hydrocarbon utilizing bacteria in the treatment microcosms after an initial decline, with strong negative correlation between bacterial abundance and TPH and PAH concentrations based on r values (0.5 − 1.0) and shared variances obtained. Bacillus, Pseudomonas and Klebsiella pneumoniae dominated as the drivers of the bioremediation process while organic acids and esters (25.0%) and ketones (14.3%) were the main biodegradation metabolite groups.

Linear and nonlinear regression modelling of industrial dye adsorption using nanocellulose@chitosan nanocomposite beads

Nanocellulose@chitosan (nc@ch) composite beads were prepared via coagulation technique for the elimination of malachite green dye from aqueous solution. As malachite green dye is highly used in textile industries for dyeing purpose which after usage shows fatal effects to the ecosystems and human beings also. In this study the formulated nanocellulose@chitosan composite beads were characterized by Particle size analysis (PSA), Field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis were done to evaluate nanoparticles size distribution, morphological behaviour, functional group entities and degree of crystallinity of prepared beads. The nanocomposite beads adsorption performance was investigated for malachite green (MG) dye and BET analysis were also recorded to know about porous behaviour of the nanocomposite beads. Maximum removal of malachite green (MG) dye was found to be 72.0 mg/g for 100 ppm initial dye concentration. For accurate observations linear and non-linear modelling was done to know about the best-fitted adsorption model during the removal mechanism of dye molecules, on evaluating it has been observed that Langmuir isotherm and Freundlich isotherm show best-fitted observation in the case of linear and non-linear isotherm respectively (R2 = 0.96 & R2 = 0.957). In the case of kinetic linear models, the data was well fitted with pseudo-second-order showing chemosorption mechanism (R2 = 0.999), and in the case of non-linear kinetic model pseudo first order showed good fit showing physisorption mechanism during adsorption (R2 = 0.999). The thermodynamic study showed positive values for ΔH° and ΔS° throughout the adsorption process respectively, implying an endothermic behaviour. In view of cost effectiveness, desorption or regeneration study was done and it was showed that after the 5th cycle, the removal tendency had decreased from 48 to 38 % for 20–100 ppm dye solution accordingly. Thus, nanocomposite beads prepared by the coagulation method seem to be a suitable candidate for dye removal from synthetic wastewater and may have potential to be used in small scale textile industries for real wastewater treatment.

Comparative evaluation of diffusion kinetics of arsenic adsorption on iron (oxy) hydroxides containing biopolymer nanocomposite beads

Exposure to arsenic-contaminated water poses great health risks to mankind. Nanocomposite beads have been proven to be an effective alternative for large-scale treatment of arsenic-loaded water. The larger size of the beads makes the adsorbent retrieval process less energy-intensive and prevents accidental leaching of nanoparticles into the surrounding environment. Adsorption using macroporous beads is predominantly a diffusion-controlled process. Therefore, in the present study, the shrinking core model (SCM) was used to compare and evaluate the diffusion kinetics of arsenic adsorption using in-situ precipitated iron (oxy)hydroxide alginate (IIAB) and chitosan beads (IICB). Simulated dynamic nondimensional liquid phase arsenic concentration profiles fit well with the experimental data (SSE = 0.018–0.025). External mass transfer coefficient (kf) and effective diffusivity coefficient (De) for both kinds of beads at different initial arsenic concentrations (C0 ∼ 1 mg.L−1 and 5 mg.L−1) were derived. By comparison of diffusivity values and the simulated concentration front profiles, it was observed that chitosan provided a better porous polymer template with more easily accessible adsorption sites covering up to 85 % of the beads’ volume. Comparison with progression conversion models has also been made to test the effectiveness of SCM fitting.

Design and synthesis of chitosan/alginate/zinc oxide nanocomposite hydrogel beads as carrier for metformin hydrochloride

In the current study, nanocomposite hydrogel beads were prepared from chitosan, alginate and zinc oxide nanoparticles using sodium tripolyphosphate as the crosslinking agent by ionotropic gelation method. The resulting nanocomposite hydrogel beads were characterized by FT-IR, XRD, TGA and UV methods and the beads were found to be an effective delivery system for the regulated release of the antidiabetic drug metformin. The swelling properties, drug loading and encapsulation efficiencies of the metformin loaded nanocomposite beads were evaluated and these parameters were found to be influenced by the concentrations of chitosan, alginate and ZnO nanoparticles. The rate of release of the drug from the nanocomposite beads was determined by UV spectroscopic method at λmax 233 nm. An increase in the concentration of ZnO enhances the swelling properties but lowers the release rate. Swelling indices of the prepared formulations were in the range 5–150. Maximum swelling index of 150 was observed for the formulation with 3 % chitosan, 2 % alginate and 15 % zinc oxide NPs. However, a maximum release rate of 83.23 % was observed for the formulation without ZnO and with 3 % chitosan, 2 % alginate. Controlled drug release was observed for the drug loaded chitosan/alginate/ZnO, hydrogel beads. The zinc oxide nanoparticles improved the in vitro α-glucosidase inhibitory activity of the formulations and the formulation with 5 % ZnO exhibited a maximum α-glucosidase inhibition rate of 62.92 %. The incorporation of ZnO nanoparticles enhanced the antioxidant properties of the formulations. The cell viability values of the samples were evaluated using L929 mouse fibroblast cells which confirmed the nontoxic nature of the samples. Dinitrosalicylic acid (DNS) studies proved that the prepared nanocomposites are biodegradable.

Zinc oxide nanoparticles encapsulated in alginate beads: a promising and recyclable adsorbent for simultaneous uptake of toxic metals

Heavy metal toxicity is a known problem and various methods are used for treatment. Adsorption has some advantages and it would be promising if environmentally friendly and cheap materials were utilized. Alginate and zinc oxide nanoparticles were selected and composite alginate beads were used for the removal of mixed metals from aqueous solutions. Batch and column experiments were conducted to determine some parameters’ effects and the adsorbent’s real application potential. According to the batch experiments, zinc oxide nanoparticles to alginate ratio of 0.5 g g−1, and pH levels nearby to the neutral range led to better metal removals. 0.5 ml min−1 of flow rate supplied better metal removal efficiencies in columns, with the highest treatment as 86% of Pb2+. Acid treatment can be successfully applied for the regeneration of the adsorbent, at least three times only with a 4% reduction in the adsorption efficiency. Heavy metal uptake was compatible with the pseudo 2nd order model indicating chemisorption as a dominant mechanism. Also, the intraparticle diffusion model illustrated adsorption might govern more than one step. The Langmuir model had the best fit and suggested monolayer covering for Pb2+, 76.3 mg g−1. Alginate-based nanocomposite beads were useful for mixed metal removal and could be used.

Tuning the wettability of alginate-based nanocomposite beads for efficient removal of pharmaceuticals from water

Long-term exposure to pharmaceuticals, such as diclofenac (DCF) and tetracycline (TC), poses various risks to human health, including antibiotic resistance and endocrine disruption. In this work, we investigated the removal of DCF and TC from water and probed the removal performance of contaminants in a complex matrix consisting of DCF and TC mixtures using alginate (AL)-based nanocomposite beads with tunable wettability. We improved the selectivity of the beads towards hydrophobic contaminants by reducing graphene oxide (GO) to rGO in the presence of AL using a mild and green reducing agent (Vitamin C). Thein-situchemical reduction of GO in AL matrix resulted in amphiphilic rGO-containing beads,as confirmed by several characterization techniques.Thein-situreduction, apart from restoring the sp2hybridized carbon, greatly improved the mechanical properties and stability of the nanocomposite, ensuring reusability beyond 10 adsorption/desorption cycles.Compared to neat AL beads, the addition of only 3.5% rGO (AL:3.5rGO) improved the beads adsorption capacity for TC and DCF by 660% and 747%, respectively. The beads exhibited remarkable performance in the simultaneous removal of TC and DCF from contaminant mixtures. The superior performance of AL:3.5rGO beads is attributed to the enhanced π-π interactions between the aromatic rings of the contaminants and the sp2domains of rGO-containing adsorbents.

Orally ingestible medication utilizing layered double hydroxide nanoparticles strengthened alginate and hyaluronic acid-based hydrogel bead for bowel disease management

In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.

Enhancing milk quality assessment with watermelon (Citrullus lanatus) urease immobilized on VS2-chitosan nanocomposite beads using response surface methodology

An eco-friendly hydrothermal method synthesized VS2 nanosheets. Several spectroscopic and microscopic approaches (TEM) were used to characterize the produced VS2 nanosheet microstructure. VS2, Chitosan, and nanocomposite were used to immobilize watermelon (Citrullus lanatus) urease. Optimization using the Response Surface Methodology and the Box-Behnken design yielded immobilization efficiencies of 65.23 %, 72.52 %, and 87.68 % for chitosan, VS2, and nanocomposite, respectively. The analysis of variance confirmed the mathematical model's validity, enabling additional research. AFM, SEM, FTIR, Fluorescence microscopy, and Cary Eclipse Fluorescence Spectrometer showed urease conjugation to the matrix. During and after immobilization, FTIR spectra showed a dynamic connectivity of chemical processes and bonding. The nanocomposite outperformed VS2 and chitosan in pH and temperature. Chitosan and VS2-immobilized urease were more thermally stable than soluble urease, but the nanocomposite-urease system was even more resilient. The nanocomposite retained 60 % of its residual activity after three months of storage. It retains 91.8 % of its initial activity after 12 reuse cycles. Nanocomposite-immobilized urease measured milk urea at 23.62 mg/dl. This result was compared favorably to the gold standard p-dimethylaminobenzaldehyde spectrophotometric result of 20 mg/dl. The linear range is 5 to 70 mg/dl, with a LOD of 1.07 (±0.05) mg/dl and SD of less than 5 %. The nanocomposite's ksel coefficient for interferents was exceptionally low (ksel < 0.07), indicating urea detection sensitivity. Watermelon urease is suitable for dairy sector applications due to its availability, immobilization on nanocomposite, and reuse.

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.

Adsorptive removal of norfloxacin from aqueous solutions by Fe/Cu CNS-embedded alginate-carboxymethyl cellulose-chitosan beads.

The pervasive application of pharmaceuticals in aquatic environments has acquired much focus owing to their nonbiodegradability and eco-toxicity, which might readily destroy the ecological balance. Developed chitosan-coated Fe-Cu CNS alginate-CMC beads (NBs) were utilized in this study to adsorb the quinolone antibiotic norfloxacin (NOR) from water for the first time. Under ideal conditions (CNOR: 20 mg L-1; sorbent conc.: 2000 mg L-1; sorbent dosage: 0.15 g; interaction time: 300 min; solution pH: 6.0), about 86% NOR removal was achieved through batch mode. The removal performance for NOR was examined concerning pH, ionic strength, and coexisting micropollutants. The greatest NOR removal was attained on NBs with the greatest Langmuir adsorption capacity of 355 mg g-1 due to numerous mechanisms such as sorbent pore filling, electrostatic attraction, π-π attraction and hydrogen bonding. Studies using environmentally significant algae, such as Scenedesmus sp., to analyze the residual toxicity of treated NOR solution revealed a significant reduction in their toxic effects. Current research has demonstrated that nanocomposite beads are an excellent wastewater treatment material with promising industrial applications due to their ease of synthesis, exceptional surface adsorption properties, stability, and environmentally friendly reaction.

Graphene Oxide-Polyphenylsulfone Nanocomposite Beads for Paracetamol Removal from Aqueous Solution.

This study introduces a promising and practical method for the removal of paracetamol from aqueous environments, employing graphene oxide-polymer nanocomposite beads. The approach involves the utilization of a straightforward and facile phase inversion method, offering a convenient and efficient one-step process for the creation of adsorbent beads by integrating polymers and graphene oxide (GO). The synthesized nanocomposite beads are tailored for the removal of paracetamol from simulated wastewater in batch systems. Extensive characterization techniques including XPS, FTIR, SEM, TGA, and zeta potential analysis are employed to scrutinize the chemical properties and structural attributes of the prepared beads. The investigation explores the impact of critical parameters such as adsorbent dosage, adsorption duration, initial paracetamol concentration, and solution pH on the adsorption process. These nanocomposite beads exhibit an exceptional paracetamol removal efficiency, achieving up to 99% removal. This research not only contributes to the advancement of efficient and sustainable adsorbent materials for pollutant removal but also underscores their potential for environmentally friendly and cost-effective solutions in the domain of wastewater treatment.