【作者】 彭玉鸽；

【导师】 黄耀熊；

【作者基本信息】 暨南大学 ， 分析化学， 2002， 硕士

【摘要】 城市用水和工业废水处理工艺中，混凝过程(混合、凝聚、絮凝)是应用最普遍的关键环节之一，强化混凝研究的重点在于使用高效低毒絮凝剂，虽然对絮凝剂的研究已有很多，但对絮凝剂分子的一些特性参数，尤其是其在纯水中自然状况下的颗粒形态结构、分子量、粒径及其分布等参数未见研究报道。本文运用激光散射技术实现了对絮凝剂这些特性参数的研究。 激光散射技术因其具有可准确、快捷及不干扰弥散物质在水中自然状况的优点，在对分散系统的测定研究中得到重要应用，本文将激光散射的技术和方法应用于絮凝剂分子特性参数的研究，首次得出了三种絮凝剂在纯水中自然状况下的有关特性参数，测定了其重均分子量Mw、流体力学半径A_h、回转半径A_g及其粒度分布等参数，并通过流体力学半径与回转半径的比值a确定出絮凝剂颗粒在水中自然状态下的形态结构。还测定了这些参数随温度和浓度的变化情况。同时研究了絮凝剂在实际运用中的去除效果实验，分析了粒径大小、分子量等参数如何影响絮凝剂的絮凝性能，以及温度、絮凝剂浓度等因素对去除率的影响机理。 结果表明，分子量大、颗粒粒度大的絮凝剂其实际去除效果优良，在相同的水温条件下，絮凝剂这些参数不随其浓度的变化而变化，但随水体温度升高，絮凝剂粒度有减小趋势。对絮凝剂机理的深入研究表明，絮凝剂分子量、颗粒粒径是影响絮凝剂吸附架桥能力的重要内部因素，絮凝剂的形态结构影响凝结聚集作用和卷扫作用，絮凝剂分子量决定其吸附性能和沉降速度。 通过系统论证说明絮凝剂分子量、粒度是衡量絮凝性能的重要因素，可作为絮凝剂产品的质量指标，同时在实际应用中应从絮凝剂这些参数入手来改善其性能。可行的途径一般是以改变聚合体或以合成复合型絮凝剂增大其粒径及分子量。通过本文的研究对絮凝剂自身因素对絮凝机理的影响有更清晰的认识，以期对评价该絮凝剂的沉降性能及有关性能的改进提高起指导作用。更多还原

【Abstract】 Coagulation is one of the most crucial step in treating industrial waste water and providing high quality water for industry & drinking. Although lots studies on flocculation have been reported, based on our knowledge, the structure, size & size distribution, the weight average molecular weight of the particle of flocculation in pure water haven’t been investigated yet. Accordingly, the purpose of the present paper is to perform research on these parameters using laser light scattering.Laser light scattering is a seasitive, accurate and nonivasive technique, which is surtable for the measurement of polydishersed system. In our study, the weight average molecular weight, the hydrodynamic radius & gyration radius, the size distribution and the shape of the particles of some flocculation (PACU PAC-V and PAM) in pure water were investigated using laser light scattering as functions of temperature and the concentration of the flocculation. Some removal efficiency measurements were also performed to check the relation between the physical parameters and the effect of the flocculation in coagulation. The investigations prove that, the molecular weight, the size & shape of flocculation strongly affect the removal efficacy, and do not change with the concentration of flocculation, but decrease with rising temperature.The results also show that the flocculation with high molecular weight and greater particle size have better performance and high efficacy in removing dust in water. Our research on the mechanism of flocculation shows that, the molecular weight and particle size of flocculation strongly affect cohesion and conjunction at the same time, the structure and shape affect coagulation, and molecular weight strongly affect the attraction and falling of the flocculation.The research indicates that molecular weight and particle size of flocculation are two of the most important factors in influencing the removal efficacy. Therefore,, several ways of increasing the values of molecular weight and the particle size have been suggested for improving the flocculation in the paper. We believe that, our investigating on these parameters will provide experimental evidence & theoretical bases for the research on flocculating mechanism.更多还原