Magnetic Biocomposites Research Articles

Vachellia nilotica sawdust-derived polymeric and magnetic biocomposites for phosphate ions removal: Kinetics, isothermal, and thermodynamic studies

Phosphorus is an important element for both animals and plants, but its excess can cause eutrophication in water. Excess phosphorus is present in wastewater mainly due to acid rain, the dissolving of rocks, and agricultural waste. There are many methods for the elimination of Phosphorus from aqueous solution, but their use is finite because of the high operational cost. Adsorption is a productive and popular method for removing phosphorus from aqueous solution. In this study, Vachellia nilotica sawdust and its different composites (Ppy/SD and MG/SD) were utilized for the effective adsorption of phosphorus from the solution. Prepared sorbents were characterized via BET, SEM, FTIR and XRD for their surface area and morphological, functional and crystallinity attributes. Adsorption tests were carried out to identify the optimal working parameters such as adsorbent dose, temperature, initial phosphorus concentration, pH, and contact time. Adsorption isotherm and kinetic model were accurately explained by the Langmuir model and pseudo 2nd order kinetics. The maximal adsorption capacity for Phosphate was 4.803, 5.32, and 6.27 mg/g for Native/SD, Ppy/SD, and MG/SD, respectively. Thermodynamic characteristics confirmed that the phosphorus adsorption was endothermic and spontaneous. Thus, sawdust is an eco-friendly and inexpensive adsorbent for phosphorus removal from wastewater.

Enhanced Copper Ion Adsorption by Rice Husk and Sugarcane Bagasse-based Magnetic Nanoparticles Biocomposites

Rice husk and sugarcane bagasse are biomass waste by-products of agriculture activities. High cellulose content makes them a potential material to develop. Biomass utilization is more interesting to develop due to its high cellulose content and nature abundance. Cellulose from rice husk and sugarcane bagasse is utilized as fiber in producing magnetic biocomposites. The Biocomposites can adsorb Cu(II) ions in aqueous solutions. A one-step solvothermal reaction was used to synthesize biocomposites. The amine functionalization on biocomposites was also studied for adsorption performance. The magnetic particle was generated on the surface of fiber and verified by XRD as Fe3O4. Amine group on biocomposites is also found on 570 cm-1 and 1636 cm−1 peaks for Fe-O bonds and N-H bending, respectively. Batch isothermal adsorption employing magnetic biocomposites has optimal conditions for Cu(II) ions adsorption at pH 5 for 60 minutes, with an adsorption capacity of 118.26 mg/g. The reusability of biocomposites for the next run showed a good performance at 3rd repetitions with only a decrease in adsorption capacity of 8.81%. The rice husk and sugarcane bagasse-based magnetic nanoparticles biocomposites can adsorb Cu(II) ions and potential material to develop for wastewater treatment.

Recyclable magnetic nickel ferrite–carboxymethyl cellulose–sodium alginate bio-composite for efficient removal of nickel ion from water

In waste water treatment, magnetic bio-composites are frequently investigated as an adsorbent recently due to their great capacity for adsorption and affordability. In this current work, an attempt has been made to develop spinel nickel ferrite–carboxymethyl cellulose (NiFCMC) composite and modified its surface by alginate polymer to form NiFCMC–Alg composite. Several techniques were utilized to characterize these adsorbents including Fourier transform infrared spectroscopy, x-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectra, thermogravimetric analysis, vibration sample magnetometry and pH of point zero charge. These adsorbents were explored to check their potentiality to remove Ni (II) ions in aqueous medium on various parameters such as contact time, initial metal ion concentration, pH, adsorbent dose and temperature. The optimum time for establishment of equilibrium was 180 minutes at pH 8 with adsorbent dose of 0.1 g. Results of kinetic studies revealed that the best fit for the metal ion adsorption data was the Lagergren pseudo-second-order mode indicating the chemisorption nature. Likewise, the Langmuir isotherm model also showed good agreement with adsorption equilibrium data with maximum adsorption capacities 47.84 ± 2.39 and 60.24 ± 3.01 mg/g for NiFCMC and NiFCMC–Alg respectively. The calculated adsorption thermodynamic parameters confirmed the spontaneous nature of adsorption process. The regeneration efficiency of both adsorbents was studied for five cycles and showed significant results. This study has shown that NiFCMC and NiFCMC–Alg can be a good substitute for removing Ni (II) ions in aqueous medium.

Hydrothermally magnetic particles fabricated hydrocalumite based biopolymeric composites for toxic chromium removal.

Hexavalent chromium is an emerging environmental pollutant that leads to various effects on living organisms. The developed clay material, hydrocalumite (HC) possesses promising chromium adsorption capacity but because of its powder form it cannot be used in column studies. Hence, it is aimed to prepared HC in an usable hybrid bio-composite form by dispersing HC in biopolymeric matrixes like chitosan (CS) and cellulose (Cel) as HCCS and HCCel bio-composites for Cr(VI) removal from water. For quick separation after adsorption, the magnetic particles sprayed HCCS (Fe3O4@HCCS) and HCCel (Fe3O4@HCCel) bio-composites were prepared which possess high adsorption capacity. Different instrumental techniques like FTIR, SEM, and EDAX studies were used to examine the synthesized magnetic bio-composites in order to determine their physicochemical properties. The promising adsorbents namely Fe3O4@HCCS and Fe3O4@HCCel bio-composites were examined for Cr(VI) removal in batch mode. The maximum chromium adsorption capacity of Fe3O4@HCCS and Fe3O4@HCCel bio-composites were foundat 43.4mg/L and 31.8mg/L, respectively within 45min. The Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) isotherms were used to reinterpret the equilibrium data of the synthetic magnetic bio-composites. According to the thermodynamic findings, chromium adsorption onto magnetic bio-composites is an endothermic and spontaneous reaction. The NaOH solution makes it simple to regenerate the chromium adsorbed magnetic bio-composites, which can be successfully employed upto four times. The synthesized Fe3O4@HCCS and Fe3O4@HCCel bio-composites act as efficient adsorbents for chromium removal.

Magnetic polylactic acid-calcium phosphate-based biocomposite as a potential biomaterial for tissue engineering applications

This work aims the manufacture of injection molded polylactic acid (PLA)-based magnetic biocomposites, presenting an alternative approach to enhance the magnetic susceptibility of PLA-based biocomposites without resorting to the exclusive incorporation of magnetic nanoparticles whose long-term side effects are still unclear. Magnetic biocomposites were obtained by incorporating 5 wt% of iron doped biphasic calcium phosphate (FeBCP) powders into the PLA matrix and compared with similar composites containing 2 and 5 wt% of non-doped BCP powder, as well as neat PLA. The chemical, thermal, mechanical, and magnetic performances were evaluated. Biodegradability according to two sterilization methods used and cytotoxicity were also assessed. The composites with FeBCP exhibited a typical ferromagnetic-like behavior and presented a superior tensile strength even with low concentrations of FeBCP, when compared to PLA or non-doped composites, besides being cytocompatible. The presented proof of concept paves the way for future developments of new magnetic PLA-based biocomposites for biomedical applications.

Investigation of capacitors and electrical circuit elements performance of magnetic biocomposites prepared by using the hemp biomass

Hemp biomass (HB) was brought into activated hemp biomass (AHB) by chemical technique and all samples were obtained by doping different nanoparticles. Structural, dielectric and magnetic characterizations for all samples were performed by using the XRD, FTIR, SEM, EDX, LCR Meter and PPMS at room temperature. The characteristics of both hemp biomass and nanoparticles in the structures of these samples were examined in detail. In addition to HB and AHB samples, the contribution of lignin and pectin characteristic bands to conductivity was investigated in AHB samples doped with Fe3O4, MgFe2O4 and SrFe2O4 nanoparticles. It has been determined that homogeneously dispersed nanoparticles contribute to surface area, crystallization and conductivity and these samples are technological products. It was determined that the samples could be used as batteries, and two electrical circuits simultaneously connected to the lignin and pectin structures of the activated hemp biomass (AHB) doped with different types of nanoparticles were obtained from the Smith-Chart diagram.

Plant mediated magnetic nano composite as promising scavenger's radionuclides for the efficient remediation in aqueous medium

The present investigation demonstrates the environment friendly plant mediated green synthesis of magnetic bio composite nanoparticles by the chemical co-precipitation of magnetite phase from aqueous medium. Water contaminated with uranium is one of the most serious environmental issues. This study aims to overcome this issue by effectively adsorbing uranium from water at a pH range of 7. Several studies have recently been published throughout the world that demonstrates uranium adsorption from water, although they have all been conducted in acidic media with pH less than 6. This work addressed that issue, and maximal adsorption was achieved at pH 7 using a synthetic magnetic bio composites sorbent derived from tree bark (Amla). The magnetic bio composites were characterized by FTIR, XRD, FE-SEM, and EDX. The computations of the XRD data indicated that magnetic bio composites have nano composite with an average diameter of around 12.1 nm. This has an adsorption capacity of 121.95 mg g−1. The correlation regression (r2) coefficients obtained for the various isotherm models indicate that the sorption process conformed to the Langmuir and Temkin models. Thermodynamic studies revealed that the sorption process onto plant mediated magnetic bio material is endothermic and spontaneous, which is significant for reuse and recovery of adsorbed material. A desorption test was also performed to regenerate the material by removing the adsorbed uranium (VI) by HCL with an 84.3% success rate.

High potential of amine rice husk magnetic biocomposites for Cu(II) ion adsorption and heterogeneous degradation of contaminants in aqueous solution

High potential of amine rice husk magnetic biocomposites for Cu(II) ion adsorption and heterogeneous degradation of contaminants in aqueous solution

Adsorptive removal of reactive green 5 (RG-5) and direct yellow 50 (DY-50) from simulated wastewater by Mangifera indica seed shell and its magnetic composite: Batch and Column study

Removal of reactive green (RG-5) and direct yellow (DY-50) dyes was carried out by native Mangifera indica (mango) seed shell biomass and its magnetic composites. After synthesis of adsorbents, surface properties of mango seed shell biomass (BN) and magnetic composites (BMc) were determined by TGA, FTIR and SEM In batch experimentation mode optimum conditions for RG-5 and DY-50 uptake were found as: contact time, 120 min and temperature 35°C, pH 7 and 2, for DY-50 uptake with both adsorbents BN and BMc respectively, in case of RG-5 the optimum temperatures were 60 and 25°C for BN and BMc respectively, optimum pH and contact time were same as DY-50. Effects of surfactants, metals and salts concentration on the biosorption capacity were also investigated. Kinetic studies showed the best fitness of pseudo-second-order kinetic model on experimental data. Langmuir showed best fitness for BMc as well as BN (RG-5) and BM for DY-50, while Temkin isotherm best fitted on BN data for DR-50, conversely Freundlich only supports the adsorption mechanism for RG-5 with BN. Thermodynamic study for RG and DY revealed the endothermic and stable biosorption onto BN and BMc. Column study parameters such as effect of bed height and concentration were investigated at constant flow rate. Kinetic models BDST (bed depth service time) and Thomas were applied on column experimental data. Outcome of this research work showed that the magnetic bio-composites prepared by mango seed shell biomass has a great potential to remove RG and DY dyes from wastewater.

Preparation of magnetic nanoparticle biocomposites using rice husk and sugarcane bagasse fibers as the matrix

Fiber is one of the important components to construct a matrix structure. Biomass is a potential material as a fiber resource for matrix. Rice husk and sugarcane bagasse consist of 36.6 % and 60% cellulose, respectively. This current research focused on evaluating the production of amine functionalized magnetic nanoparticle biocomposites produced by mixture of rice husk (RH) and sugarcane bagasse (SB) fibers. First, RH and SB fibers were dried and crushed close to 60 mesh for each, followed by a delignification at 80 °C for 2 h in 1% w/v of NaOH. Through by one-step solvothermal process, it was done by adding delignified ratio of RH and SB fibers (1:1; 1:2; 1:3; 1:4) to mixture of ethylene glycol, FeCl3.6H2O, and 1.6-hexanediamine at 200 °C for 6 h. The magnetic nanoparticles appeared on the fibers surface which contained 97.97% Fe. The magnetite was formed proved by the specific peaks at 36°, 43°, and 57° by X-Ray Diffraction.(XRD). The Fourier Transformed Infrared (FT-IR) identified N–H bending vibration and Fe-O in the biocomposites at 1640 cm−1 and 582 cm−1, respectively. The restructure of matrix, iron, and amine groups on the biocomposites surface can affect the adsorption capacity of various waste water treatments.

Synthesis and characterization of amine-functionalized sugarcane bagasse fiber magnetic nanoparticle biocomposites

Sugarcane bagasse is one of the by-products in the sugar industry which contains 60% of cellulose. Cellulose can be used as a matrix for biocomposite. The purpose of this research was to produce amine-functionalized sugarcane bagasse fiber magnetic nanoparticle biocomposites (SBB). The SBB was produced from sugarcane bagasse (SB) by solvothermal reaction. The SB was dried and blended into small size (±60 mesh), then lignin was removed with 1% NaOH (w/v) through the delignification. The biocomposites was made by adding delignified SB (SB-D) into a mixture of ethylene glycol, FeCl3.6H2O, and hexamethylenediamine (HMDA) in solution, and then heated for 6 h at 200 °C. HMDA as an amine source was applied different concentrations (5, 7, and 9 mL). The surface morphology of biocomposites was covered by the magnetic nanoparticles along SB-D which contained amine of about 17.78 mmol/g. The Fe content of SBB was 98.34% which had specific peaks for magnetite at 36°, 43°, and 57° which were measured by X-Ray Diffraction (XRD). The Fourier Transformed Infrared (FT-IR) identified N–H bending vibration on SBB at 1640 cm−1. The iron content and amine group on the surface may affect high adsorption capacity for a wide range of biological pollutants.

A label-free electrochemical biosensor based on magnetic biocomposites with DNAzyme and hybridization chain reaction dual signal amplification for the determination of Pb2.

A highly sensitive and selective electrochemical biosensor for Pb2+ with a dual-amplification strategy is proposed. The first amplification step was realized by the cycle of Pb2+ and 8-17 DNAzyme (S2), and the hybridization chain reaction (HCR) triggered by S1 further amplified the electrochemical signal. Fe3O4@Au NPs, as a multifunctional magnetic carrier, is not only manifested in the construction of a magnetically controlled electrochemical response interface, but also has significant contribution in the purifying system, reducing interference, increasing the specific surface area, and the DNA loading. The magnetic nanocomposites were characterized by TEM as spheres with particle size of around 39nm. When there was no Pb2+, long double-strand DNA (dsDNA) is formed on the surface of Fe3O4@Au NPs by the S1-triggered HCR; in the presence of Pb2+, S2 is activated and S1 on the surface of magnetic biocomposites (Fe3O4@Au NPs-S1) is continuously cleaved with the cycle of Pb2+ and S2, leading to a significant decrease of methylene blue (MB) absorbed on dsDNA. Such reverse dual-signal amplification strategy effectively increased the current difference and improved the sensitivity of the proposed sensor. The electrochemical signal of MB was obtained by differential pulse voltammetry (DPV) with preconcentration, showing a linear response toward Pb2+ ranging from 50pM to 1μM with a detection limit of 15pM. The proposed method has feasible applications in detecting other heavy metal ions based on other metal-dependent DNAzyme. Graphical Abstract.

A label-free electrochemical magnetic aptasensor based on exonuclease III–assisted signal amplification for determination of carcinoembryonic antigen

A novel label-free and exonuclease III (Exo III)-assisted signal amplification electrochemical aptasensor was constructed for the determination of carcinoembryonic antigen (CEA) via magnetic field-induced self-assembly of magnetic biocomposites (Fe3O4@Au NPs-S1-S2-S3). The magnetic biocomposites were acquired by modifying double-stranded DNA (S1-S2-S3) on the surface of Fe3O4@Au nanoparticles (Fe3O4@Au NPs). Among them, Fe3O4@Au NPs were used as carriers for magnetic separation, thiolated single-stranded DNA (S1) provided signal sequence, CEA aptamer (S2) worked as a recognition element, and complementary strand (S3) was used to form double strands. In the presence of CEA, S2 bonded with CEA competitively; the exposed S1 could not be cleaved since Exo III was inactive against ssDNA. The G-quadruplex/hemin complexes finally formed with the existence of K+, and the high electrochemical signal of G-quadruplex/hemin complexes was recorded by differential pulse voltammetry (DPV) at - 0.6V. Conversely, in the absence of CEA, dsDNA was cleaved from the 3' blunt end by Exo III; the disappearance of G-rich sequence blocked the generation of the signal. This method exhibited goodselectivity and sensitivity for the determination of CEA; the linear range was from 0.1 to 200ngmL-1 and the limit of detection was 0.4pgmL-1. Graphical abstract.

Selective adsorption of Pb(II) ion on amine-rich functionalized rice husk magnetic nanoparticle biocomposites in aqueous solution

Amine group on rice husk magnetic nanoparticle bicomposites (RHB-MH) was synthesized by one-step solvothermal method. The new finding of biocomposites is utilization of rice husk cellulose as a support which produced high amine content on surface of magnetic nanoparticle (MNPs). The rice husk cellulose (RH-D), iron(III) chloride hexahydrate, Na-acetate anhydrate were mixed in ethylene glycol, then kept at ±200 °C for 6 h. Amine modified MNPs was constructed by addition of 1,6-hexanediamine in mixture before the reaction. The MNPs was growth on surface of RH-D then formed biocomposites. The Fe content about 93.11 % and the magnetic nanoparticle structure was proved by specific peaks at 36°, 43°, 63° for magnetite. The magnetic saturation value of biocomposites about 16.4 emu/g. The thermal stability of biocomposites showed up to 200 oC with less than 10 % of mass degradation. Higher amine content of 12.3 mmol/g on biocomposites was achieved after addition of 7 mL of 1,6-hexanediamine (RBH-MH2). Amine functional group on biocomposites exhibited the resonance bands at 1645 cm−1 and 1050 cm−1. The adsorption of Pb(II) ion on RBH-MH2 follows pseudo 1 st order kinetic and well-fitted by Langmuir adsorption isotherm model which have maximum capacity of 680.19 mg/g at room temperature and pHe∼5. The RBH-MH2 have significant effect to capture Pb(II) ion due to electrostatic interaction and showed 3.6-fold higher adsorption capacity than rice husk biocomposites without modification. The amine-rich on biocomposites does not only provide an easy retrievable from aqueous solution but also potential candidate for effective green adsorbent.

Low-cost sugarcane bagasse and peanut shell magnetic-composites applied in the removal of carbofuran and iprodione pesticides.

In the present study, two agro-industrial wastes, sugarcane bagasse, and peanut shell were employed as support of magnetite nanoparticles for the synthesis of magnetic bio-composites: magnetic sugarcane bagasse (MBO) and magnetic peanut shell (MPSo). The presence of magnetite was verified by Raman spectroscopy. Magnetic nanoparticles shape and size distribution were studied by TEM, while composites morphologies were observed by SEM. Structural characteristics of the pesticides and their possible chemical adsorption on composites were analyzed by FTIR. The removal was carried out by a batch adsorption process, and UV-VIS technique was used for pesticide concentration estimation. Elovich model described better all systems pointing out to a chemical adsorption process occurring. Experimental data isotherms of carbofuran and iprodione can be best explained by more than one mathematical model, but Sip was the ordinary equation in all systems. Maximum adsorption capacities of 175 and 89.3mg/g for carbofuran, and 119 and 2.76mg/g for iprodione, were obtained for MBo and MPSo, respectively.

Preparation and pH Controlled Release of Fe3O4/Anthocyanin Magnetic Biocomposites.

Anthocyanins are a class of antioxidants extracted from plants, with a variety of biochemical and pharmacological properties. However, the wide and effective applications of anthocyanins have been limited by their relatively low stability and bioavailability. In order to expand the application of anthocyanins, Fe3O4/anthocyanin magnetic biocomposite was fabricated for the storage and release of anthocyanin in this work. The magnetic biocomposite of Fe3O4 magnetic nanoparticle-loaded anthocyanin was prepared through physical intermolecular adsorption or covalent cross-linking. Scanning electron microscopy (SEM), Dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and thermal analysis were used to characterize the biocomposite. In addition, the anthocyanin releasing experiments were performed. The optimized condition for the Fe3O4/anthocyanin magnetic biocomposite preparation was determined to be at 60 °C for 20 h in weak alkaline solution. The smooth surface of biocomposite from SEM suggested that anthocyanin was coated on the surface of the Fe3O4 particles successfully. The average size of the Fe3O4/anthocyanin magnetic biocomposite was about 222 nm. Under acidic conditions, the magnetic biocomposite solids could be repeatable released anthocyanin, with the same chemical structure as the anthocyanin before compounding. Therefore, anthocyanin can be effectively adsorbed and released by this magnetic biocomposite. Overall, this work shows that Fe3O4/anthocyanin magnetic biocomposite has great potential for future applications as a drug storage and delivery nanoplatform that is adaptable to medical, food and sensing.

Magnetic biocomposites as support for trypsin immobilization: application for protein digestion

The aim of this study was to improve the ability of Aspergillus terreus lipase to separate the racemic ketoprofen vinyl ester into individual enantiomers using hollow self-assembly alginate-graft-poly(ethylene glycol)/α-cyclodextrins (Alg-g-PEG/α-CD) spheres as enzyme immobilization carriers. The morphology and size of the Alg-g-PEG/α-CD particles were investigated by transmission electron microscopy (TEM) and were found to be nanoscale. To facilitate recycling, calcium alginate (CA) beads were developed to encapsulate Alg-g-PEG/α-CD particles, thereby producing Alg-g-PEG/α-CD/CA composite beads. The influence of buffer pH and enzyme concentration during immobilization was studied along with the biocatalyst's kinetic parameters. When the immobilized enzyme was under optimal conditions in the resolution reaction, maximal conversion (approximately 45.9%) and enantioselectivity (approximately 128.8) were obtained. The immobilized A. terreus lipase maintained excellent performance even after 20 reuses and retained nearly 100% of its original activity after 24 weeks of storage at 4 °C.

A label-free electrochemical aptasensor based on magnetic biocomposites with Pb2+-dependent DNAzyme for the detection of thrombin

Herein, a novel magnetic biocomposite (Fe3O4@Au-S1/S2) was applied to analyze thrombin. The Fe3O4@Au-S1/S2 consisted of Fe3O4@Au nanoparticles (Fe3O4@Au NPs) as carriers for magnetic separation and magnetic field-induced self-assembly, thiolated complementary strand (S1) anchored based on Au-S bond and thrombin binding aptamer (S2) as a recognition element. As a redox indicator, methylene blue (MB) can be adsorbed to DNA anchored on the surface of Fe3O4@Au NPs by electro-static interaction. In the absence of thrombin, MB were adsorbed on double-stranded DNA (S1/S2) which anchored on Fe3O4@Au NPs and a high electrochemical signal of MB was recorded by Differential pulse voltammetry. Conversely, the complementary strand (S1) exposed after thrombin competitively bonded with aptamer. The introduction of Pb2+-dependent DNAzyme (S3) split S1 at specific rA site, resulting in the significantly decreased adsorption capacity of MB. Thus, the thrombin detection could be recorded by monitoring the electrochemical signal reduction of MB through incubation of thrombin with S3. This method exhibited a high sensitivity toward thrombin with a broad linear range from 5 pmol L−1 to 5 nmol L−1 and a limit of detection of 1.8 pmol L−1.

Enhanced Chromium Sorption and Quick Separation of Magnetic Hydrotalcite Anchored Biopolymeric Composites Using the Hydrothermal Method

The magnetic hydrotalcite supported biopolymeric composites were synthesized by hydrothermal (Hydro) and in situ precipitation (in situ) methods for selective chromium removal. A comparative evaluation of chromium sorption capacity (SC) of both hydrothermal and in situ synthesized magnetic biocomposites namely Fe3O4@alginate/hydrotalcite (Fe3O4@AlgHT) composite, Fe3O4@chitosan/hydrotalcite (Fe3O4@CSHT) composite, and Fe3O4@gelatin/hydrotalcite (Fe3O4@GelHT) composite was carried out. The hydrothermally synthesized magnetic biocomposites demonstrated greater chromium SC than in situ method. The synthesized materials were characterized by Fourier transform infrared spectrometer, X-ray diffraction, Brunauer–Emmett–Teller, ultraviolet–visible spectrophotometer, vibrating sample magnetometer, transmission electron microscope, scanning electron microscope, and energy dispersive X-ray analysis. The equilibrium data of the synthesized magnetic biocomposites were explained by Langmuir, Freundlich, and Dubinin–Radushkevich (D-R) isotherms. The thermodynamic result shows that the nature of chromium sorption onto the magnetic biocomposites is spontaneous and endothermic. The kinetic models suggested that the chromium sorption behavior follow pseudo-second-order and intraparticle diffusion models. The chromium sorbed magnetic biocomposites can be easily regenerated using NaOH and can be effectively used up to five cycles. The suitability of the magnetic biocomposites at field conditions was inspected by field water sample.

Magnetic Zinc Ferrite–Alginic Biopolymer Composite: As an Alternative Adsorbent for the Removal of Dyes in Single and Ternary Dye System

Recently, magnetic bio-composites as adsorbent are widely being explored in waste water treatment because of their exceptional properties like high adsorption capacity, selectivity and cost-effective nature. In the present study, a novel recyclable magnetic composite containing magnetic zinc ferrite and alginate in alginic form (ZnFN–Alg) was developed. Various techniques like Fourier Transform-Infra Red, X-ray diffraction, transmission electron microscope with energy dispersive spectra, Brunauer–Emmett–Teller, thermo gravimetric-differential thermal analysis and Point Zero Charge (pHzpc) were used to characterize the surface morphology of magnetic composite. The magnetic composite was used as adsorbent to remove congo red, crystal violet and brilliant green dyes in single and ternary systems. The kinetic studies data was best fitted to Lagergren pseudo second order whereas mechanism of adsorption was described by intra particle diffusion model in single as well as ternary systems. The adsorption equilibrium data was best fitted to Langmuir isotherm among various adsorption isotherm models. Thermodynamic studies confirmed that the adsorption process was spontaneous in nature. The regeneration ability of ZnFN–Alg composite was studied individually in single and ternary dye systems for seven cycles and showed significant results. It was concluded that magnetic ZnFN–Alg can serve as suitable alternative for the removal of dyes in single and ternary systems.