淀粉基絮凝剂的制备及其对污水中Pb^(2+)的去除研究

Preparation of flocculant based on starch and the removal of Pb^(2+) in wastewater

以红薯淀粉、丙烯腈(AN)为主要原料,硝酸铈铵为引发剂,得到腈基淀粉微球,再用N,N-二甲基甲酰胺作为溶剂,在反相溶液中以盐酸羟胺还原,得到拥有大量氨基的改性淀粉絮凝剂。通过对该絮凝剂的红外表征、形貌观察、孔径分布和比表面积测试,可初步判断其吸附的有效官能团—NH_2和—OH是存在的,初步获得吸附所需的孔径分布和比表面积。由此特性,完成以硝酸铅配制模拟吸附溶液,探讨其在不同投入量、pH值及吸附时间等条件下对Pb^(2+)的吸附能力,从而达到最佳的吸附率,确立优化条件,对西安市昆明路和汉城湖污水中的Pb^(2+)进行吸附,其吸附率约在60%左右。

These starch microspheres with group-CN were obtained by used sweet potato starch and acrylonitrile as the main raw material,and cerium ammonium nitrate was acted as initiator in the reversed solution. Modified starch flocculant containing a large number of amino was acquired between the reduction of hydroxylamine hydrchloride and N,N-dimethylformamide as solvent. Main groups of flocculant was infrared in FT-IR,its morphology was observed by scanning electron microscopy（ SEM）. The distribution of pore and specific surface area（ BET） were tested. It showed that the functional groups -NH2,-OH were appeared in modified starch flocculant,distribution of pore size and surface area were required for the adsorption. By means of these characteristics,workers had completed the preparation of adsorption simulation as lead nitrate solution and then explored the adsorption capacity of Pb^2＋under the factors of different inputs,pH value and adsorption time. And the optimum removal condition was achieved. Finally,the actual wastewater adsorption of Pb^2＋was tested under the optimum condition. As a result,the removal ratio of Pb^2＋in wastewater was about 60%.