双氰胺—甲醛絮凝脱色剂的合成与应用研究

【作者】 黎载波；

【导师】 王国庆；

【作者基本信息】 广东工业大学 ， 化学工艺， 2003， 硕士

【摘要】 印染废水的处理是一个具有重大实用价值的研究课题。本文在阐述印染废水的来源、特征及国内外印染废水处理技术的基础上，系统地进行了用尿素改性制备双氰胺-甲醛絮凝脱色剂的合成反应研究，对合成工艺条件进行优化，并进行了双氰胺-甲醛絮凝脱色剂在印染废水处理中的应用性能研究。研究表明，实验制备的产品具有优良的脱色性能和COD_Cr去除性能，制备工艺易于控制，为印染废水的处理提供了一种新型的性能优良的絮凝脱色剂。实验的主要内容包括： （1） 以双氰胺与甲醛的缩聚反应为主反应，用尿素部分取代双氰胺，制备了双氰胺-甲醛絮凝脱色剂。通过实验证明了在不影响产品性能的前提下，用尿素对双氰胺-甲醛缩合物进行改性的方法来降低生产成本是可行的，进行了确定尿素最大取代用量及其制备反应的控制的研究。 （2） 对产品的分子量及其离子类型进行了测定，用红外光谱进行了基团分析，表明实验制备的产品是一种分子链中具有带正电性质基团的低聚物，在水溶液中呈现阳离子聚电解质的特性，产品的物理性质良好，适于在废水处理中应用。 （3） 考察了反应条件的控制、反应原料配比、反应时间、反应温度等因素对产品性能的影响规律。在对上述因素进行实验条件变化范围的初选的基础上，以对混合染料废水的脱色效果及COD_Cr，去除效果为评价指标，确定了最佳的合成条件：反应温度65℃；反应时间3小时；反应物配比为（双氰胺：尿素）：氯化铵：甲醛=（0.714：0.286）：0.9：1.4；1～2℃／min的升温速率。对产品的性能影响最大的因素为甲醛的用量和反应的温度。 （4） 以最佳合成条件下制得的产品应用于模拟染料废水的处理中，分别考察了双氰胺-甲醛絮凝脱色剂对活性染料、酸性染料和分散染料废水的脱色性能和COD_Cr去除性能，寻找出实验产品在上述染料废水处理中的使用特性。 （5） 进行了采用双氰胺-甲醛絮凝脱色剂对实际印染废水处理的可行性研究。以单因素实验考察了药剂投加量、废水的pH值及与其它药剂的配合使用等工艺条件对处理效果的影响规律。处理后排水的最佳处理效果为残留COD_Cr值76.1mg/L，色度接近无色，表明实验产品是处理印染废水的一种有效的絮凝脱色 广东工业人学硕士学位论文一＃U。更多还原

【Abstract】 Treating the printing and dyeing wastewater is an important task with practical value. On the basis of surveying the resource, character and treatment approaches inside and outside of country of printing and dyeing wastewater, reaction of synthesizing dicyanodiamide-formaldehyde decolourizating flocculant modified by urea was studied systematically in this paper .The synthetic condition was optimized and the application performance of dicyanodiamide-formaldehyde polymer on printing and dyeing wastewater was also studied. Results showed the excellent performance of decolourization and removal of CODcr and operation condition of product easily controlled. It provided a new-type decolourizating flocculant with high efficiency applying in printing and dyeing wastewater treatment. The main contents of experiment were as follows:(1) By the main polymerizing reaction between dicyanodiamide and formaldehyde, the decolourizating flocculant was prepared and modified by urea .The results showed it is feasible to reduce producing cost by using urea and the optimatic dosage of urea and the condition of reaction were studied.(2) By the measurement of molecular weight, ion types and the function analysis of IR spectrum, the product was indicated to be a kind of oligomer with positive electricity function. The product showed the. character of electrolytical polymer and adapt to applying in wastewater treatment with fine physical property.(3) The rules influenced by many factors, such as reaction condition, reactant proportion, reaction temperature and time, was draw out. On the basis of selection of the range of experiment condition, the optimum symthetic condition was determined by the evaluation criterion of the removal of CODcr and decolourization. The optimization was to be: reaction time:3 hours; reaction temperature: 65 ; reactant proportion (dicyanodiamide:urea):ammonium chloride : formaldehyde =(0.714:0.286):0.9:1.4; rate of raising temperature: l~2 /min. In every factor that influenced the performance of product, the usage of formaldehyde and reaction temperature was the most importantfactor.(4) The performance of the removal of CODCr and decolonization of dicyanodiamide-formaldehyde polymer prepared in the optimum condition applying in reactive, acid and disperse dye-containing wastewater treatment was researched and the application character was found out.(5) The feasibility of dicyanodiamide-formaldehyde flocculant applying in practical printing and dyeing wastewater was studied. The rules influenced by technologic conditions such as dosage, pH value of wastewater and the use of composite agent were studied by single factor experiment .The result of treatment showed that the product was a kind of effective decolourizating flocculant applying in printing and dyeing wastewater with the best effect of treatment: CODCr remained 76.1 mg/L and decoloured almost.更多还原