交联羧甲基玉米淀粉对水溶液中铅离子吸附性能的优化研究
Study on adsorption performance of cross-linked carboxymethyl corn starch on lead ions in aqueous solution
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摘要: 以玉米淀粉为原料，采用先醚化后交联改性工艺合成了交联羧甲基玉米淀粉吸附剂。在单因素试验的基础上，采用Box-Benhnken的中心组合试验设计及响应面分析法，研究了交联羧甲基玉米淀粉吸附剂用量、吸附时间和pH值3因素对水溶液中铅离子吸附效果的影响，得出了吸附剂对铅离子吸附效果的回归模型。结果表明，最佳吸附工艺参数为吸附剂用量0.22 g，pH值为6.6，吸附时间32.9 min，交联羧甲基玉米淀粉对铅离子吸附容量可达44.72 mg/g，铅离子去除率达到98.38%。常温下吸附动力学模型符合Freundlich等温式Q=0.4152C0.9894。采用0.9 mol/L盐酸溶液作为解析液，铅离子回收率可达97.55%。Abstract: The cross-linked carboxymethyl modified starch（CCMS）adsorbent was prepared by the reaction of corn starch with monochloroacetic acid first under the dry condition，then by the reaction of carboxymethyl starch with epichlorohydrin as crosslinking agent under ethanol water condition.The effects of reaction time, modified starch content and pH on the adsorption performance to lead ions in aqueous solution were studied on the basis of the results of single factor tests，according to box behnken factorial design principle and response surface methodology analysis and the regression equation of the modification parameters was established.The optimum technology conditions were confirmed as follows：the adsorbent content 0.22 g, pH 6.6, adsorption time 32.9 min, the maxium value of loading capacity was up to 44.72 mg/g and the maximum removal rate of Pd2+could reach 98.38%.The adsorption ability of CCMS adsorbent was conformed with Freundlichi sotherm adsorption Q=0.4152C0.9894. The maxium recovery ratio of Pd2+ was up to 97.55% when 0.9 mol/L HCl agueous solution was used in the desorption process.
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Key words:
- crosslinked carboxymethyl /
- adsorption /
- desorption /
- response surface methodology
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