改性多孔淀粉对Cu^(2+)的捕集性能

Chelating Property of Modified Porous Starch for Cu^(2+)

以玉米淀粉为原料,采用糖化酶和α-淀粉酶复合酶解制成多孔淀粉,多孔淀粉经交联、间接醚化、胺化、黄原酸酯化反应得到二硫代氨基甲酸基改性多孔淀粉(DTCPS)重金属捕集剂。研究了DTCPS对Cu2+的捕集性能。实验结果表明:制得的多孔淀粉的比表面积为1.264 5m2/g,比玉米淀粉的比表面积增大了138.5%;制得的多孔淀粉是一种中孔淀粉;Cu2+溶液pH为1~5时,DTCPS的Cu2+饱和捕集量均较高;Cu2+初始质量浓度为0~70m g/L时,DTCPS对Cu2+的捕集性能很好,溶液中Cu2+的剩余质量浓度低于0.12m g/L,Cu2+的去除率达99%以上。DTCPS对Cu2+的捕集性能明显优于二硫代氨基甲酸基改性淀粉(DTCS)。

Corn starch was used as raw material to prepare porous starch by enzymatic hydrolysis method with glucoamylase and α-amylase. Sequently, dithiocarbamate-porous starch （DTCPS）, a heavy metal chelating agent, was prepared from porous starch by crosslink, indirect etherification, amination and esterification with xanthic acid. The chelating property of DTCPS for Cu^2＋ was studied and the experimental results show that： The specific surface area of porous strach is 1. 264 5 m^2/g, which is 138.5% larger than that of com starch; The prepared porous starch is a mesoporous starch; When the pH of Cu^2＋ solution is in the range of 1 - 5, the chelating capacity of DTCPS for Cu^2＋ is high; When the initial mass concentration of Cu^2＋ is 0 - 70 mg/L, the mass concentration of residual Cu〉 in solution is less than 0.12 mg/L and the removal rate of Cu^2＋ is more than 99%. The chelating property of DTCPS for Cu^2＋ is obviously better than that of dithiocarbamate-starch （DTCS）.