Calcium Alginate Beads with Entrapped Iron Oxide Magnetic Nanoparticles Functionalized with Methionine—A Versatile Adsorbent for Arsenic Removal

Abstract

A novel beads adsorbent, consisting of calcium alginate entrapped on magnetic nanoparticles functionalized with methionine (MFMNABs), was developed for effective elimination of arsenic from water. The material was characterized by FT-IR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscopic), XRD (X-ray Diffraction) and TEM (Transmission Electron Microscopy). The arsenic removal capacity of the material was studied by altering variables such as pH of the solution, contact time, adsorbent dose and adsorbate concentration. The maximal removal of As(III) was 99.56% under optimal conditions with an equilibrium time of 110 min and pH 7.0–7.5. The adsorption followed a second order kinetics and data best fitted the Langmuir isotherm with a correlation coefficient of R2 = 0.9890 and adsorption capacity (qm) of 6.6533 mg/g. The thermodynamic study showed entropy change (∆S) and enthalpy change (∆H) to be 34.32 J mol−1 K and 5.25 kJ mol−1, respectively. This study proved that it was feasible to treat an As(III) solution with MFMNABs. The synthesized adsorbent was cost-effective, environmentally friendly and versatile, compared to other adsorbents. The adsorption study was carried by low cost spectrophotometric method using N- bromosuccinimide and rhodamine-B developed in our laboratory.

Arsenic Remove from Apatite-Soil Treated Waters’ Using Magnetic Zero Valent Iron Doped Polyethersolfun Beads

“…Synthesis of magnetic zero valent iron particles (ZVI) from ferrous was carried out by the precipitation method [11]. 2.4 g of ferrous chloride (Fe 3+ ) were dissolved in 50 mL DDW separately and 15 mL 1.5 M of NaBH4 was added dropwise with stirring at 50 °C.…”

“…Iron-based adsorbents have been extensively developed and indicated acceptable extraction efficiency for arsenic species from environmental samples [10]. Iron-based adsorbents such as granular ferric hydroxide and zero-valent iron (ZVI) have been produced as commercial adsorbents to uptake arsenic [11]. Although, the disadvantages of some commercial adsorbents such as interfering with other ions present in soil or water well-reported.…”

Magnetic Beads of Zero Valent Iron Doped Polyethersolfun Developed for Removal of Arsenic from Apatite-Soil Treated Water

“…The synthesis of magnetic zero-valent iron particles (ZVI) from ferrous was carried out by the precipitation method [11]. A total of 2.4 g of ferrous chloride (Fe 3+ ) was dissolved in 50 mL of DDW, separately, and 15 mL of 1.5 M of NaBH 4 was added dropwise, with stirring taking place at 50 • C. The black precipitate was separated magnetically and washed three times with DDW and ethanol and dried at 80 • C for 90 min (see Equation ( 1)).…”

“…The application of iron-based adsorbents is well-documented, owing to the acceptable extraction efficiency for arsenic species from environmental samples [10]. Moreover, granular ferric hydroxide and zero-valent iron (ZVI) have been produced as commercial adsorbents to uptake arsenic [11]. Although, there are some disadvantages to ZVI adsorbents such as its fast oxidation in aqueous media, due to the small size of ZVI, it can easily be agglomerated via the van der Waals attractive, which leads to bigger particles, decreasing the reactivity [12,13].…”

Immobilization of Horseradish Peroxidase on Magnetite-Alginate Beads to Enable Effective Strong Binding and Enzyme Recycling during Anthraquinone Dyes’ Degradation

“…However, Mag have some limitations in practical application, such as instability (easily oxidized in air), easy agglomeration, problematic distribution and collection [31]. Integrating Mag into other materials to create composite or hybrid materials (e.g., carbon nanotubes with Mag, biopolymers conjugated with Mag) [32][33][34] or coating of Mag with some polymer (e.g., alginate, polyacrylic acid, poly(vinyl alcohol), polyethyleneimine, poly(isobutylenealt-maleic anhydride) polyethylene glycol, starch, methoxypoly(ethylene glycol)) [35][36][37][38][39] are the main strategies used for solving these shortcomings of Mag. Herein, we propose embedding Mag into hydrogel mm-or µm-scale particles (beads) which combine advantages of both (gel particles and Mag)-rapid separation by external magnetic field and/or gravitational settling due to high density, stability against dissolution especially at lower pH of solution, amplified enzyme activity and a number of available methods able to give large amounts of beads under mild and simple preparation conditions.…”