Synthesis And Application Of Schiff Base Resins Of Dialdehyde Starch

Heavy metal pollution represents an important environmental problem due to its toxic effects and accumulation throughout the food chain and hence in the human body. In recent years, using cheaper and more effective adsorption materials have become a research hotspot in the heavy metal adsorption. Biopolymers represent an interesting and attractive alternative as natural material is first selection research object. This thesis intends to use natural polymer starch as adsorbent material, the oxidated starch selectively oxidated by periodate of stoichiometric amount was investigated systematically in this paper, the chelating resin was prepared from a reaction between dialdehyde starch (DAS) and ligand, and used for heavy metal ions and adsorption properties were studied.This thesis mainly research content:1、Design and synthesis of three different oxidation degree of dialdehyde starch DAS1, DAS2, DAS3. Schiff base type starch dialdehyde o-phenylenediamine (DASPDA) was synthesized by the reaction of o-phenylenediamine and dialdehyde starch (DAS), and characterized by element analysis, FT-IR spectra, SEM and TG.2、The aim of the work was to prepare starch DASPDA to determine the ability of these adsorbents in removing nickel (Ⅱ) ion from aqueous medium. The adsorption results revealed that the optimal pH was 5.0, the equilibrium time was about 120 min. Moreover, the adsorption isotherm and thermodynamics parameters of the adsorption were also investigated. the Freundlich adsorption isotherm gave a satisfactory fit of the equilibrium, and the adsorption process is endothermic. The chelating of Ni (Ⅱ) ions to DASPDA by adsorption is enhanced as the temperature increases.3、A novel chelating material was prepared from o-phenylenediamine starch by reacting with ethylenediaminetetraacetic dianhydride (EDTAD). Batch adsorption experiments were carried out as a function of adsorption time, pH and initial Ni (Ⅱ) ions concentrations. The adsorption reached equilibrium in a short time, the optimum pH rang was from 5 to 6. The Langmuir adsorption isotherm gave a satisfactory fit of the equilibrium. the adsorbed Cu2+ and Pb2+ ions can be desorbed by treating with HCl solution and the desorption percentage reached above 99% when desorbing with 1 M HCl solution for 30 min。...