摘要：

以玉米淀粉（St）为原料，环氧氯丙烷（EPI）为交联剂，甲基丙烯酰氧乙基三甲基氯化铵（DMC）为接枝单体，两步法合成了接枝交联双重改性淀粉基絮凝剂IStD。测试了投药量、pH、高岭土质量分数、絮凝温度和絮凝时间对IStD絮凝性能的影响。结果表明，当高岭土质量分数为2%，投药质量浓度为14 mg/L，pH=7，絮凝温度为25 ℃，絮凝时间为1 h时，上清液的透光率可达91.7%。通过观察投药前后水体中高岭土颗粒的分散状态，初步探讨了IStD的絮凝机理。结果表明在絮凝过程中，同时存在电中和与吸附架桥作用，以电中和作用为主。当IStD和CPAM复配用于处理生活废水时，透光率和COD去除率都能达到90%以上，具有一定的实用价值。

关键词: 改性淀粉, 甲基丙烯酰氧乙基三甲基氯化铵, 絮凝

Abstract:

Using corn starch（St） as raw material，epichlorohydrin（EPI） as cross-linking agent and （2-methacryloxyethyl） trimethyl ammonium chloride（DMC） as grafting monomer，a grafted cross-linked double modified starch-based flocculant IStD was synthesized by two-step method. The effects of dosage，pH，percentage content of kaolin，flocculation temperature and flocculation time on flocculation performance of IStD were tested. The results showed that under the condition of the percentage content of kaolin 2%，the dosage 14 mg/L，pH=7，the flocculation temperature 25 ℃，and the flocculation time 1 h，the light transmittance of the supernatant could reach 91.7%. The flocculation mechanism of IStD was preliminarily discussed by observing the dispersion of kaolin particles in water before and after dosing. The results showed that there were both electric neutralization and adsorption bridging in the flocculation process，and the electric neutralization was the main one. When IStD and CPAM were combined to treat domestic wastewater，the transmittance and COD removal rate could reach more than 90%，which had certain practical value.

Key words: modified starch, （2-methacryloyloxyethyl） trimethyl ammonium chloride, flocculation

中图分类号: 

• X703.5