Authors: Xianyu Li Anyang Hu Lin Ye
Publish Date: 2011/02/25
Volume: 19, Issue: 2, Pages: 398-404
Abstract
The porous polyvinylalcohol PVA hydrogel was prepared by chemical crosslinking in the saturated boric acid solution with sodium bicarbonate SBC as porogen It was found that addition of SBC decreased the mechanical strength of the gel beads while the gel permeability was improved The equilibrium swelling rate and the swelling rate constant k of gel beads increased significantly by addition of SBC Most of water in PVA hydrogel was in the form of free water and freezing bound water With increasing SBC content the total water content of the gel increased in which the free water content increased remarkably due to the formation of a large number of pores and in the meantime n values characterizing the mole content of nonfreezing bound water were also improved greatly indicating of the enhancement of the interaction between PVA molecules and water molecules SEM observation showed that by adding SBC many pores formed on the surface and inside gels which provided channels for microbial metabolites Microorganism could be successfully entrapped in the porous PVA beads and addition of SBC made COD removal rate of the gel beads increase significantly
Keywords: