淀粉基絮凝剂的制备及废水应用的研究进展

Research progress on the preparation of starch-based flocculants andwastewater application

淀粉是一种来源广泛,价廉,可生物降解的天然高分子材料,分子内含有多个易改性的羟基,通过改性可以得到多种淀粉衍生物。用淀粉及其衍生物作絮凝基体制备不同絮凝剂,既能有效絮凝污染物又不易产生二次污染。通过醚化、酯化、接枝共聚改性淀粉,可去除水中的胶体物质和可溶性污染物,用于处理成分复杂的纺织印染废水,目前纺织印染多使用易上染的阴离子染料,废水中也多含此类型离子染料,将淀粉改性为强絮凝性的阳离子型絮凝剂是解决印染废水排放问题的希望。综述了国内外淀粉基絮凝剂研究现状,从制备方法、种类、机理以及表面电荷、分子量和絮凝时的外部环境对絮凝效果的影响因素进行阐述,指出了应该探究对淀粉絮凝剂改性更有效的预处理方法和引发体系,实现绿色絮凝,提高絮凝效果,并解决絮凝产生的大量污泥等问题。

Starch is a kind of natural polymer material with a wide range of sources,low price,and biodegradable.It contains multiple easily modified hydroxyl groups in the molecule.A variety of starch derivatives can be obtained through modification.Starch and its derivatives are used as flocculation matrix.The preparation of different flocculants can effectively flocculate pollutants and is not easy to produce secondary pollution.Through etherification,esterification and graft copolymerization of modified starch,colloidal substances and soluble pollutants in water can be removed,and it can be used to treat textile printing and dyeing wastewater with complex components.At present,textile printing and dyeing mostly use anionic dyes that are easy to dye.It contains more ionic dyes of this type,and modifying starch into a cationic flocculant with strong flocculation is the hope to solve the problem of printing and dyeing wastewater discharge.The research status of starch-based flocculants at home and abroad is reviewed,and the factors influencing the flocculation effect of the preparation method,type,mechanism,surface charge,molecular weight and the external environment during flocculation are described.It points out that the modification of starch flocculant should be explored to be more effective.The pretreatment method and the initiation system of the company can realize green flocculation,improve the flocculation effect,and solve the problems of large amounts of sludge produced by flocculation.