Photocatalytic magnetic separable beads for chromium (VI) reduction.
Magnetically separable photocatalyst beads containing nano-sized iron oxide in alginate polymer were prepared. This magnetic photocatalyst beads are used in slurry-type reactors. The magnetism of the catalyst arises from the nanostructured particles gamma-Fe(2)O(3), by which the catalyst can be easily recovered by the application of an external magnetic field. These synthesized beads are sunlight-driven photocatalyst. In the system without magnetic photocatalyst beads, no chromium reduction was observed under sunlight irradiation due to the stability of the chromium (VI). Upon the addition of magnetic photocatalyst beads, the photo-reduction of Cr(VI) was completed in just after only 50min under sunlight irradiation due to the photocatalytic activity of the beads. However when placed away from sunlight, the reduction rate of the chromium is just about 10%. These observations were explained in terms of absorption occurrence of chromium (VI) onto the catalyst surface which took place in this reaction. In addition, photo-reduction rate of chromium (VI) was more significant at lower pH. The results suggest that the use of magnetic separable photocatalyst beads is a feasible strategy for eliminating Cr(VI).
Idris
Ani
A
Department of Bioprocess Engineering, Faculty of Chemical and Natural Resource Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia. ani@fkkksa.utm.my
Hassan
Nursia
N
Mohd Ismail
Nur Suriani
NS
Misran
Effaliza
E
Yusof
Noordin Mohd
NM
Ngomsik
Audrey-Flore
AF
Bee
Agnes
A
D000464:Alginates / Q000737:chemistry; D002384:Catalysis / Q000528:radiation effects; D002857:Chromium / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008027:Light; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D010316:Particle Size; D010777:Photochemistry; D014961:X-Ray Diffraction
D000464:Alginates; D005290:Ferric Compounds; D006603:Hexuronic Acids; D002857:Chromium; C000499:ferric oxide; D020723:Glucuronic Acid