利用壳聚糖涂层PVC珠吸附去除废水中铜和镍---英文资料翻译.docVIP

Adsorptive removal of copper and nickel from water uising chitosan coated PVC Beads 2. Methods 2.1 Materials Analytical grade nickel ammonium sulphate and copper sulphate were purchased from S.D. Fine chemicals. for nickel(Ⅱ) and copper(Ⅱ) ion sources. Hydrochloric acid and sodium hydroxide used for pH adjustment were obtained from Chemical Drug House Ltd.India. Commercial PVC beads and chitosan were purchased from Aldrich Chemical Company.USA.Highly pure water is prepared in the laboratory by double distillation of deionised water in quartz distillation plant(Bhanu Scientific Company.Banglore.India). The stock solutions of Cu(Ⅱ) and Ni(Ⅱ) were prepared by dissolving 3.929g of copper sulphate and 6.7302g of nickel ammonium sulphate in 1000ml of double distilled water such that eath ml of the solution contains 1 mg of divalent metal. The exact concentration of each metal ion solution was calculated on mass basis and expressed in terms of mg L-1 .The required lower concentrations were prepared by dilution of the stock solution .All precautions were taken to minimize the loss due to evaporation during the preparation of solutions and subsequent measurements .the stock solutions were prepared fresh for each experiment as the concentration of the stock solution may change on long standing. 2.2 Preparation of chitosan coated PVC beads Medium molecular weight chitosan was sieved to remove dust and small particles. The sieved chitosan was boiled for 30 min and rinsed several times with deionized double distilled water to desorb any impurities from the chitosan. Then, dried under vacuum for 3 days and kept in desiccators before use. About 30 g of chitosan was slowly added to 1 L of 0.2 M oxalic acid solution under continuous stirring at 40-50℃ for about 4h to facilitate the formation of viscous gel. The gel was allowed to stay over night to enable the gas bubbles to escape. PVC beads were first stirred with 0.2 M oxalic acid for 6h at room temperature.filtered and washe