title: Synthesis and characterization of magnetic chitosan microspheres as low-density and low-biotoxicity adsorbents for lake restoration.
abstract: We propose a novel magnetic adsorbent for optimal Phosphorus (P) removal from the upper sediment layers. For this aim, magnetic chitosan microparticles were prepared using a reverse-phase suspension cross-linking technique. The resulting particles and suspensions were characterized using scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, magnetometry, thermogravimetric analysis, electrophoretic mobility and turbidity measurements. The hybrids are multicore particles consisting of well dispersed magnetite nanoparticles (approx. 10% w/w) homogeneously distributed within the biopolymer matrix. These microparticles can be easily separated from the water column and sediment using magnetic field gradients. Their P adsorption capacity is evaluated in batch conditions resulting in a maximum P adsorption capacity of ML= 4.84 mg g-1at pH = 7. We demonstrate that these particles are excellent candidates to remove P from water column and also P mobile from the upper sediment layers due to two main reasons: they sediment slower and present lower potential toxicity (due to a their larger size) than conventional iron/iron oxide microparticles previously proposed for lake restoration.
authors.affiliation: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Spain; Instituto del Agua, Universidad de Granada, 18071, Spain. Electronic address: afunes@ugr.es.
authors.forename: A
authors.initials: A
authors.lastname: Funes
authors.affiliation: Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Granada, 18071, Spain.
authors.forename: J
authors.initials: J
authors.lastname: de Vicente
authors.affiliation: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Spain; Instituto del Agua, Universidad de Granada, 18071, Spain.
authors.forename: I
authors.initials: I
authors.lastname: de Vicente
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods; D006863:Hydrogen-Ion Concentration; D060106:Lakes; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010758:Phosphorus / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D058185:Magnetite Nanoparticles; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D048271:Chitosan
keywords: Emulsion; Eutrophication; Magnetic chitosan; Magnetite; Phosphorus