Characterization And Applications Of Porous Chitosan Membranes

This paper has four chapters and the main results are as following:In chapter 1: the exordium. Firstly, the stucture, properties and the applications in wastewater treatment of chitosan were described. Secondly, the characterisations of chitosan membrane, the applications in carrier materials of immobilized enzyme, wastewater treatment and the present research situation of chitosan membrane were introduced. The significance of study on the applications of porous chitosan membrane in wastewater treatment was reviewed.In chapter 2: the adsorption of Cd( II) ion by porous chitosan membrane was investigated. The effects of Cd( II) ion concentration, adsorbing time, system pH value and temperature on the adsorption were discussed. The regeneration method of the porous chitosan membrane was also researched. It is shown that the porous chitosan membrane has good kinetic properties-uneasily running off and being regenerated easily as well as the ability to absorb Cd( II) ion. For the porous chitosan membrane, the optimum pH value of adsorption Cd(II) ion is 6.0～7.3, and the absorption velocity is fast. The porous chitosan membrane is expected to be used to treat the wastewater containing Cd(II) ion, recover cadmium or be as the adsorbent for Cd( II) ion.In chapter 3: urease was immobilized on porous chitosan membrane. The activity of the immobilized enzyme was studied. The localization of activity of urease immobilized on porous chitosan membrane was studied by X-ray microanalysis. And the effects of the order of immobilization and crosslinking were discussed. The immobilized enzyme was used to hydrolyze urea. And the influence of different conditions to the hydrolysis efficiency was researched. It is shown that the porous chitosan membrane possesses more amount of urease; The X-ray microanalysis shows that the distribution of active enzyme on the surface of the porous chitosan membrane is uniform. The urease immobilized on the porous chitosan membrane maintains the high catalytic activity and storage stability. When pH is between 6.0 ～ 7.0 and the temperature is at 37 ℃, urea is hydrolyzed by immobilized urease...