Magnetic poly(styrene–glycidyl methacrylate) porous microspheres (MPPM) with high magnetic contents were prepared by surfactant reverse micelles and emulsion polymerization of monomers, in which the well-dispersed Fe 3 O 4 nanoparticles were modified by polyethylene glycol (PEG) and oleic acid (OA) respectively. The characterizations showed that both of the OA–MPPM and the PEG–MPPM were ferromagnetic, however, the OA–MPPM was used to immobilize the bacteria for more advantages. Therefore, the effects of monomer ratio, surfactant, crosslinker and amount of Fe 3 O 4 on the structure, morphology and magnetic contents of the OA–MPPM were investigated. Then, the OA–MPPM was utilized to immobilize Klebsiella sp. FD-3, an iron-reducing bacterium for Fe(III)EDTA reduction applied in NO x removal. Compared with free bacteria, the immobilized FD-3 showed a better tolerance to the unbeneficial pH and temperature conditions.
Fe 3 O 4 poly (styrene-glycidyl methacrylate) magnetic porous microspheres (MPPMs) were introduced to immobilize Klebsiella sp. FD-3, an iron-reducing bacterium applied to reduce Fe(III)EDTA. The effects of potential inhibitors (S 2− , SO 3 2− , NO 3 − , NO 2 − and Fe(II)EDTA-NO) on Fe(III)EDTA reduction were investigated. S 2− reacted with Fe(III)EDTA as an electron-shuttling compound and enhanced the reduction. But Fe(III)EDTA reduction was inhibited by SO 3 2− and Fe(II)EDTA-NO due to their toxic to microorganisms. Low concentrations of NO 3 − and NO 2 − accelerated Fe(III)EDTA reduction, but high concentrations inhibited the reduction, whether by free or immobilized FD-3. The immobilized FD-3 performed better than freely-suspended style. The substrate mass transfer and diffusion kinetics in the porous microspheres were calculated. The value of Thiele modulus and effectiveness factors showed that the intraparticle diffusion was fairly small and neglected in this carrier. Fe(III)EDTA reduction fitted first-order model at low Fe(III)EDTA concentration, and changed to zero-order model at high concentrations.
危险品化学品经营许可证（带存储）