School of Environment, Tsinghua University, Beijing 100084, PR China.
School of Environment, Tsinghua University, Beijing 100084, PR China.
Int J Biol Macromol. 2018 Oct 15;118(Pt B):1431-1437. doi: 10.1016/j.ijbiomac.2018.06.155. Epub 2018 Jul 1.
To pursuit effective and environmentally friendly flocculant, a bio-copolymer was prepared by starch grafting with acrylamide (AM) and dimethyl diallyl ammonium chloride (DMDAAC) through an initiator system KMnO/HIO. The initiation and grafting reaction were optimized by the Response Surface Methodology. In the initiation reaction, the optimum condition was KMnO at 0.28 mmol, HIO at 0.25 mmol, and the temperature at 67.64 °C, when the highest copolymer yield of 13.43 g was obtained from 4 g raw starch. In the grafting reaction, the optimum condition was the temperature at 68.71 °C, (AM + DMDAAC)/starch anhydroglucose units molar ratio at 2 and the AM / (AM + DMDAAC) molar ratio at 0.34, when the copolymer had the maximum cationic degree of 1.54 meq/g. The optimized preparing method had a high grafting efficiency of 97.12 ± 0.14% and high raw material utilization. The flocculation ability of the optimized graft copolymer was also tested. The result showed the graft starch was effective to remove reactive dyes and disperse dyes from wastewater. The dye removal efficiency of the graft starch was nearly 10% higher than polyacrylamide. Therefore, through the optimization of initiation and grafting reaction, the graft starch was a promising environmentally friendly flocculant.
为了寻求高效且环保的絮凝剂，通过引发剂体系 KMnO/HIO，采用淀粉与丙烯酰胺（AM）和二甲基二烯丙基氯化铵（DMDAAC）接枝共聚的方法制备了一种生物共聚物。通过响应面法对引发和接枝反应进行了优化。在引发反应中，当 KMnO 为 0.28mmol、HIO 为 0.25mmol、温度为 67.64°C 时，得到了最高的共聚产率 13.43g，从 4g 原淀粉中获得。在接枝反应中，当温度为 68.71°C、(AM+DMDAAC)/淀粉无水葡萄糖单元摩尔比为 2 和 AM/(AM+DMDAAC)摩尔比为 0.34 时，共聚物的最高正电荷度为 1.54meq/g。优化的制备方法具有 97.12%±0.14%的高接枝效率和高原料利用率。还测试了优化接枝共聚物的絮凝能力。结果表明，接枝淀粉对废水中的活性染料和分散染料具有良好的去除效果。接枝淀粉的染料去除效率比聚丙烯酰胺高近 10%。因此，通过引发和接枝反应的优化，接枝淀粉是一种很有前途的环保絮凝剂。
