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 ¼ 4.84 mg g 1 at pH ¼ 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.The authors would like to thank F. Galisteo-Gonz alez for
providing the Bool2k software used for the generation of particlesize
distributions from SEM micrographs and F. Vereda for his
help in the Chemistry Laboratory. This workwas supported by Junta
de Andalucía projects of excellence P10-RNM-6630 and P11-FQM-
7074 (Spain); MINECO CTM 2013-46951-R, MAT 2013-44429-R and
PCIN 2015-051, MAT 2016-78778-R projects (Spain); and by the
European Regional Development Fund
