【作者】 杨飞飞；

【导师】 王栋；

【作者基本信息】 大连理工大学 ， 环境工程， 2010， 硕士

【摘要】 表面活性剂是难溶且具有环境风险的有机物在水中的载体,基于阴离子表面活性剂的环境危害性以及工业用水中含有大量钙盐的事实,表面活性剂废水的混凝处理受到普遍关注。为了更好地去除水体中残留的表面活性剂,文章以自来水中钙的浓度0.0014mol/L为参考,选用十二烷基苯磺酸钠(Sodium Dodecylbenzenesulfonate,简写为SDBS)和十二烷基硫酸钠(Sodium Dodecyl Sulfate,简写为SDS)为研究对象,在298.15K下对浓度大于临界胶束浓度(Critical Micelle Concentration,简写为CMC)和小于CMC的SDBS、SDS溶液与铝盐的混凝特征及钙盐对SDBS、SDS溶液与铝盐混凝特征的影响进行了对比研究,具体混凝特征参数包括Zeta电位、表面张力、平均粒度、电导率、pH等,实验结果表明：(1)浓度大于CMC和浓度小于CMC的SDBS、SDS溶液分别与铝盐混凝,达到最佳混凝的Al(Ⅲ)与表面活性剂的摩尔比(简称为凝聚计量摩尔比CAl/C表面活性剂)不同,推测最佳凝聚计量摩尔比与胶束的存在有关。(2)在SDBS/Al3+体系中,浓度大于CMC的0.01 mol/L SDBS和浓度小于CMC的0.001 mol/L SDBS与铝盐达到最佳混凝时的pH值均在3.5左右；在SDS/AlCl3体系中,浓度大于CMC的0.01mol/L SDS和浓度小于CMC的0.001mol/L SDS与铝盐达到最佳混凝时的pH值均在4.0以下。(3)在0.01mol/L SDS与Al3+混凝体系和O.Olmol/L SDS所在的Ca2+/SDS/Al3+反应体系中,能观察到混凝体完全消失并不再浑浊的现象。而在加钙和不加钙的0.001mol/L SDS与Al3+混凝体系、SDBS/A13+混凝体系和Ca2+/SDBS/Al3+反应体系中都观察不到混凝体完全消失的现象。(4)Ca2+的加入对体系达到最佳混凝时的凝聚计量摩尔比、电导率和pH范围没有明显的影响。(5)Ca2+的加入使0.01 mol/L SDBS存在的SDBS/Al3+体系的粒度最大峰值显著下降,推断是由于Ca2+与高浓度SDBS反应生成小粒度的Ca(DBS)2引起的。(6)Ca2+的加入使0.01mol/L SDS所在的SDS/Al3+反应体系的Zeta电位绝对值和表面张力都有所增大,而使0.001mol/L SDS所在的SDS/Al3+反应体系的Zeta电位绝对值和表面张力值均有所下降。更多还原

【Abstract】 Surfactant is a carrier of insoluble environmental hazardous substances to water body, it is becoming an ubiquitous question in aquatic environment owing to its popular usage. To enhance removal efficiency of residual surfactents in water system, the coagulation characteristics of anionic surfactants Sodium Dodecylbenzenesulfonate (SDBS) and Sodium dodecyl sulfate (SDS) of concentrations above and below the critical micelle concentration (CMC) using different dosage of AICl3 salt and the effect of an divalent electrolyte Ca2+ on the coagulation of anionic surfactants SDBS and SDS with Al3+ were investigated at 298.15K. The water used in this paper was 0.0014 mol/L CaCl2 solution, and its concentration was determined on the referencess of tap water. The coagulation characteristics of Zeta potential, surface tension, z-average size, electrical conductivity and pH were determined at 298.15K.Results showed that,(1) The optimum coagulation molar ratios of anionic surfactants SDBS and SDS of concentrations above and below the CMC with Al3+ were obviously different, this may be on account of the presence of micelles.(2) At optimization coagulation areas, pH values of SDBS/Al3+ and SDS/A13+ coagulation systems were around 3.5 and below 4.0 respectively whether the surfactant concentrations above or below the CMC.(3) The aggregates completely disappeared were observed only in two systems of SDS (0.01 mol/L)/Al3+ and Ca2+/SDS(0.01 mol/L)/Al3+, but not observed in the systems of SDS (0.001 mol/L)/Al3+, SDBS/Al3+ and Ca2+/SDBS/Al3+.(4) The effect of Ca2+ on the optimum coagulation molar ratios, conductivity and pH of coagulation of anionic surfactants with Al3+ were ignored.(5) Comparing SDBS/A13+ and Ca2+/SDBS/Al3+ systems, the z-average size value of coagulation of SDBS(0.01 mol/L)/Al3+ was larger than that of Ca2+/SDBS(0.01mol/L)/Al3+ system owing to the formation of the precipitate of Ca(DBS)2 possiblely.(6) Comparing SDS/Al3+ and Ca2+/SDS/Al3+ systems, Zeta potential absolute value and surface tension value of SDS(0.01mol/L)/Al3+ system were smaller than Ca2+/SDS(0.01mol/L) /Al3+ system, but the Zeta potential absolute value and surface tension value of SDS(0.001mol/L)/Al3+ system were larger than Ca2+/SDS(0.001mol/L)/Al3+ system.更多还原