【作者】 孙希孟；

【导师】 余学军； 赵永德；

【作者基本信息】 河南大学 ， 高分子化学与物理， 2003， 硕士

【摘要】 印染废水量大面广，脱色困难，属难处理的工业废水之一。絮凝沉降法是印染废水脱色的重要方法，而合成高分子絮凝剂的研究工作是絮凝沉降法的核心。双氰胺－甲醛聚合物对脱色具有特殊的功能，本文通过对其合成和性能的研究，期望获得脱色性能优良的絮凝剂。论文以双氰胺、甲醛为主要原料，加入不同的催化剂和改性剂，合成了双氰胺－甲醛类缩聚物；研究了温度、催化剂、改性剂对产物脱色性能的影响，优选出DFA脱色絮凝剂；用IR、1HNMR、13CNMR、DEPT表征其分子结构；胶体滴定法测定其电荷密度；外推法测定特性粘数表征其分子量；用平衡渗析实验进行了絮凝剂DFA与活性艳红X-3B相互作用的热力学研究；分析了染料及絮凝剂分子结构与脱色效果的关系；研究了摇动方式、絮凝剂用量、温度、pH值、染料浓度等条件对脱色效果的影响，得到最佳脱色条件；对DFA絮凝剂用于印染、印花废水的脱色处理进行了初步研究，并对工业应用价值作简单分析评价。结果表明：（1） NH4Cl为改性剂，酸性盐AlCl3·6H2O为催化剂制得的缩聚物DFA具有良好的脱色性能，经胶体滴定法确定其为阳离子型聚合物，其电荷密度、特性粘数均比未加铝盐催化的聚合物增大。（2）IR、1HNMR、13CNMR、DEPT光谱表明缩聚物结构中含有多种活性基团，能与染料发生多种作用而絮凝脱色，其链节结构为以下几种链接方式：<WP=6>（3）研究了絮凝剂DFA的结构与性能的关系，结果表明提高分子量和电荷密度可以提高聚合物的絮凝脱色性能。（4） 热力学研究表明键合常数K1 随温度的变化而变化，在温度为303K时，达到最大值，一方面证实了絮凝剂DFA与染料相互作用为电中和、吸附架桥脱色机理，另一方面也表明聚合物－溶剂相互作用也是重要的影响因素。（5）通过研究影响脱色絮凝效果的因素，对于脱除浓度为500ppm的染料废水，得到最佳脱色条件为：絮凝剂DFA浓度为300－600mg/l，pH值4－10，温度20－30℃，在以上条件下，絮凝剂DFA对多种染料模拟废水和工业印染、印花废水均具有较高脱色率和脱色速度，具有潜在应用价值。（6）通过多种絮凝剂对染料模拟废水脱色性能对比分析，表明絮凝剂DFA脱色性能优于聚丙烯酰胺类、PAN-DCD、无机絮凝剂， DC-491等。更多还原

【Abstract】 Wastewater containing water-soluble dyes is one of sewages that are most difficult to be treated. Conventional flocculants widely used in the treatment of wastewater containing suspended dyes usually yield poor decoloration rate in the treatment of wastewater containing dissolved dyes. The cationic condensation polymer of dicyanodiamide(DCD) and formaldehyde(HCHO) showed special performance in the decolorization of wastewater containing dissolved dyes. On the basis of the investigation of factors affecting the polymerization of DCD-HCHO and properties of DCD-HCHO polymers, a highly efficient decolorizing flocculant nominated DFA is synthesized using AlCl3·6H2O as catalyst and NH4Cl as modifier. The molecular structure of DFA is characterized by IR, 1HNMR and 13CNMR. Its electric charge density and intrinsic viscosity are measured. The interaction between active red X-3B and DFA is studied thermodynamically with the method of equilibrium dialysis. Factors affecting the flocculation of dye solution, such as shaking style, temperature, pH and dye concentration of the solution, electric charge density and intrinsic viscosity of flocculants, are discussed. The qualitative relationship between the structures of various dyes and their decoloration efficiency is analyzed. DFA shows a high performance in decolorizing solutions of active dye, acidic dye and direct dye as well as suspension of vat dye and disperse dye. Preliminary tests show DFA a potential decolorizing flocculant in the dispose of wastewater from printing and dyeing plants. The following conclusions can be drawn from the research:<WP=8>(1) DFA, a DCD-HCHO polymer synthesized using AlCl3.6H2O as catalyst and NH4Cl as modifier, is a highly efficient cationic decolorizing flocculant. Its electric charge density and intrinsic viscosity are higher than the corresponding polymer prepared in the absence of AlCl3·6H2O.(2)Characterization of DFA by IR, 1HNMR and 13CNMR shows it possesses several active groups that can react with dyes in one or another way to perform decolorization. Some possible chain segment structures are listed below:(3) Study of the structure-property relationship of DFA manifest that electric charge density and intrinsic viscosity are directly related to decolorizing efficiency. Decolorizing efficiency is improved with the increase of electric charge density and intrinsic viscosity of flocculants.(4) Thermodynamical study of the interaction between active red X-3B and DFA shows that the binding constant K1 varies with temperature and gets<WP=9>its summit on a temperature of 303K(30℃). The result suggests that the mechanism of decolorizing flocculation of dye solution with DFA is a multiple function of electric neutralization, absorptive bridging and interaction between flocculant and solvent.(5) Study of factors affecting the flocculation of dye solution gives the optimized conditions of decolorizing operation: DFA concentration:300-600mg/L;pH:4-10;temperature:20-30℃.(6)The decolorizing performance of DFA for solutions of active dye, acid dye ,direct dye and suspension of vat dye and disperse dye as well as wastewater from printing and dyeing plant is compared with that of polyacrylamide(PAM),polyacrylnitrile-dicyanodiamide ，polymer(PAN-DCD), DC-491(a commercially available DCD-HCHO polymer flocculant) and several other flocculants. The decolorizing performance of DFA is superior to that of PAM,PAN-DCD,DC-491,etc.更多还原