title: Design and performance of magnetic composite particles for the separation of heavy metals from water.
abstract: Composite particles have been made by combining nanosized polymer particles with magnetite microparticles using a ball-mill process. The magnetite particle cores were included to facilitate the composite particles separation by use of a magnetic field. Polymer particles carried carboxylic groups as ion-exchange vehicles. The composite particles were used in the extraction/stripping of Zn, Cu, Ni, and Cr from aqueous solutions in a stirred batch reactor of laboratory scale. The extraction behavior of these metals was studied as a function of initial metal concentrations of up to 25 mM, ionic strength at pH (5-7), and temperature (1-80 degrees C). Experimental results showed that the process was very fast and yielded complete metal removal when the initial concentrations of metals were very low. The selectivity series was Cu > Cr > Zn > Ni. The effect of ionic strength was immaterial at pH 7. However, extraction decreased with increasing ionic strength at pH 5. Extraction increased with increasing temperature. A series of extraction/ stripping experiments indicated that the particles can be reused without significant loss in their extraction capacity.
authors.affiliation: Department of Chemical Engineering and Chemical Technology, Imperial College of Science, Technology and Medicine, UK. pp298@ic.ac.uk
authors.forename: P
authors.initials: P
authors.lastname: Phanapavudhikul
authors.forename: J A
authors.initials: JA
authors.lastname: Waters
authors.forename: E S
authors.initials: ES
authors.lastname: Perez de Ortiz
mesh_terms: D006863:Hydrogen-Ion Concentration; D008280:Magnetics; D019216:Metals, Heavy / Q000737:chemistry / Q000302:isolation & purification*; D036103:Nanotechnology; D010316:Particle Size; D011108:Polymers; D018508:Water Purification / Q000379:methods*
chemical_list: D019216:Metals, Heavy; D011108:Polymers