Microwave preparation and properties of O-crosslinked maleic acyl chitosan adsorbent for Pb ~(2+) and Cu ~(2+)

摘要

A novel chitosan-based adsorbent (CCTM) was prepared by the reaction of epichlorohydrin O-crosslinked chitosan with maleic anhydride under microwave irradiation. The chemical structure of this polymer was characterized by infrared spectroscopy and X-ray diffraction analyses. The effects of various variables such as degree of substitution, adsorption time, initial metal ion concentration, solution pH, and temperature, on the adsorption of Pb ~(2+) and Cu ~(2+) by CCTM were investigated. The results demonstrate that the microwave irradiation can remarkably enhance the reaction. CCTM has higher adsorption capacity than chitosan. The maximum adsorption capacities for Pb ~(2+) and Cu ~(2+), with initial concentrations of 0.02 mol L ~(-1) at pH 5, are 246.3 and 132.5 mg g ~(-1), respectively. The adsorbent can be recycled. These results have important implications for the design of effective chitosan-based adsorbents in the removal of heavy metal ions from wastewaters.