低游离甲醛双氰胺甲醛缩聚物絮凝脱色剂的制备  

Preparation of the flocculation bleaching agent of dicyandiamineformaldehyde condensation with low free formaldehyde

作　　者：张恒[1,2] 许磊[1] 李鹏飞[1] 鲁俊良 张媛[1] 李军训 

机构地区：[1]青岛科技大学化工学院,山东青岛266042 [2]华南理工大学制浆造纸工程国家重点实验室,广东广州510640 [3]泰安生力源生物工程有限公司,山东泰安271000

出　　处：《河北工业科技》2016年第5期423-427,共5页Hebei Journal of Industrial Science and Technology

基　　金：山东省科技重大专项(新兴产业)(2015ZDXX0403B03);制浆造纸工程国家重点实验室开放基金(201474);青岛科技大学大学生创新创业训练计划项目(201601008)

摘　　要：为了提高对废水的脱色效率,以双氰胺、甲醛和氯化铵为主要原料合成了水溶性阳离子絮凝脱色剂,考察了投料比、反应温度、反应时间等因素对絮凝脱色剂脱色效果的影响,优选了絮凝脱色剂合成的工艺条件。结果表明,双氰胺、甲醛和氯化铵物质的量比为1∶2.1∶0.9,反应温度为60℃,反应时间为2.5h,pH值为10,脱色剂用量为1.0%时所得絮凝脱色剂的脱色效果最佳。通过实验还探讨了絮凝脱色剂中游离甲醛的去除机理及最优去除方案。结果表明,先加入n(双氰胺)∶n(甲醇)=1∶2.8,再加入n(双氰胺)∶n(尿素)=1∶0.04,反应温度为50℃,反应时间为4h,可使游离甲醛含量降到0.124%,最终合成低游离甲醛、高脱色率的絮凝脱色剂。In order to improve the efficiency of decolorization of wastewater,a water-soluble cationic dicyandiamide formaldehyde bleaching agent is synthesized with dicyandiamide,formaldehyde and ammonium chloride.The paper investigates the influence of the ratio of dosage,temperature,reaction time,etc.on the decolorization effect of the flocculant,and optimizes the process conditions for the synthesis of the flocculant.The results indicates that it could reach the optimal decolorization rate when the molar ratio of dicyandiamide to formaldehyde and ammonium chloride is 1∶2.1∶0.9,the temperature is 60 ℃,the reaction time is 2.5h,the pH value is 10,and the dosage of bleaching agent is 1.0%.The removal mechanism and optimal removal schemes of free formaldehyde are also discussed through experiment.The experimental results show that when the molar ratio of dicyandiamide and urea is 1∶0.04 after adding dicyandiamide and methyl alcohol with the ratio of 1∶2.8,the temperature is 50 ℃,and the time for the reaction is 4h,it could decrease formaldehyde to less than 0.124%,and finally theflocculant with low free formaldehyde and high efficiency of decolorization is synthesized.

关 键 词：水污染防治工程 双氰胺 甲醛 絮凝脱色剂 废水处理 

分 类 号：X793[环境科学与工程—环境工程]