【作者】 陈湘；

【导师】 王祥荣；

【作者基本信息】 苏州大学 ， 纺织化学与染整工程， 2008， 硕士

【摘要】 印染废水色度深、颜色多变,是一类难处理的工业废水。对印染废水的处理,目前普遍采用的处理方法是化学絮凝与生化工程结合的方法。因此,絮凝剂在印染废水处理过程中起着十分关键的作用。壳聚糖因其独特的分子结构,对许多类型的染料废水具有良好的絮凝作用。本文主要研究了壳聚糖改性物的合成及其在印染废水中的应用,以开发新型絮凝剂。首先研究了壳聚糖分子量和脱乙酰度对壳聚糖絮凝性能的影响,结果表明:分子量为80万壳聚糖的絮凝性能优于分子量为40万壳聚糖;脱乙酰度对壳聚糖絮凝性能几乎没影响。分别用AM、DMDAAC、EPTMAC对两种分子量壳聚糖(40万、80万)进行化学改性,并通过红外光谱对产物进行表征,讨论了改性单体和壳聚糖分子量对改性物絮凝性能的影响,结果表明,EPTMAC对大分子量为80万壳聚糖的改性物HACC絮凝性能最佳。研究了壳聚糖(分子量为80万)脱乙酰度与EPTMAC用量对合成反应的影响,制备不同取代度的HACC并用红外谱图进行结构表征,研究HACC对多种染料的絮凝性能,考察了HACC投入量,搅拌方式,沉降时间等对絮凝效果的影响。实验表明,酸性染料、活性染料出现脱色率峰值时HACC的投入量分别为10mg/L-20mg/L,20mg/L-40mg/L,HACC对分散染料的脱色率达95%以上,出现脱色率峰值的投入量基本上为100mg/L;搅拌方式对絮凝效果有重要影响,在快速搅拌和慢速搅拌两个过程中,需选择恰当的搅拌速度和搅拌时间;HACC对大部分染料的吸附作用在60min左右基本稳定,继续延长沉降时间,絮凝效果仅稍微增加。研究了HACC对印染助剂和工厂废水的絮凝作用。结果表明,HACC对扩散剂NNO和木质素磺酸钠的去除率达80%以上;HACC与PAC协同处理工厂废水,不但可以大大减少HACC的用量,而且脱色率有所提高,脱色率为90%,CODcr去除率达92%。更多还原

【Abstract】 Printing and dyeing wastewater is a kind of industry wastewater to be hardly treated with the characteristics of high chroma and changeful colour.The industrialized way is a combinative method with flocculation and biology.So flocculantion plays an important part in dealing with . Chitosan had good flocculating effect to many kinds of dyes because of its special molecular structure. This paper studied the synthesis of modified chitosan and its application in printing and dyeing wastewater.The main contents and conclusions are described as follows:The first work of this paper studied the factors which affected flocculating effect of chitosan,such as molecular weight,degree of deacetylation(DD). The experiment results indicated that the flocculating effect of chitosan with molecular weight 8.0×105 is better than chitosan with molecular weight 4.0×105. Degree of deacetylation(DD) has little affection to flocculating effect.Then different kinds of new modified chitosan absorbent were synthesized with chitosan(CS),acrylamide(AM),dimethyl diallyl ammonium chloride(DMDAAC),2,3-epoxy propyl-trimethyl ammonium chloride(EPTMAC) as raw materials.The products were confirmed by FTIR.The flocculating effect of modified chitosan to acid dyes was studied.The results indicated EPTMAC and chitosan with molecular weight 8.0×105 were the best raw materials.Different styles modified chitosan(HACC) were prepared using EPTMAC and chitosan with different DD and the products were confirmed by FTIR .It was studied that the factors affected flocculating effect of HACC,such as dosage of flocculant ,settlement time blending way and so on.The results showed the decolouration rate of acid dyes and reactive dyes treated with HACC obtained maximum value when the dosages of HACC were 10-20mg/L,20-40mg/L. The decolouration rate of disperse dyes was above 95% ,at the same time,the dosages of HACC were nearly 100mg/L .Blending way had important affection to flocculating effect ,so correct blending speed and blending time were necessary.Adsorption function to most kinds of dyes became steady when settlement time was 60 min.The flocculating effect can only be raised a little as blending time became longer.Flocculating effect to dyeing assistants and wasterwater from factory was studied.The results showed the decolouration rate of dyeing assistants were above 80%.Dealing with wasterwater from factory with HACC and PAC together ,it not only reduced the dosage of modified chitosan,but also added the decolouration rate to 90% and added the reduced rate of CODcr to 92%.更多还原