【作者】 孙明；

【导师】 田禹；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2006， 硕士

【摘要】 活性污泥法是倍受环境工程师欢迎的一种水处理方法,活性污泥法处理废水要得到最终理想的效果,污泥沉降泥水分离是关键的一步。要得到良好的沉降性能,首先要形成良好的活性污泥絮凝体。因此关于絮凝体形成的机理研究不断,迄今为止关于絮凝体形成机理研究结果有很多,但是活性污泥复杂的成分和结构,使得各种结论都无法概括所有情况,需要进一步的研究加以完善。胞内聚合物是细菌体内碳源和能源贮藏的一种方式,包括糖原、PHB、聚磷酸盐、硫粒等。胞外聚合物是包围在细胞膜外的物质,一般为聚糖、蛋白质、核酸、类脂、腐殖质、纤维等。通常认为胞外聚合物是具有粘性的物质,对污泥的絮凝和沉降有很重要的作用。虽然胞内聚合物和胞外聚合物在生物合成中没有直接联系,但是从培养基质种类、合成和降解阶段等方面可以发现两者存在联系。尤其在活性污泥的絮凝和沉降方面,胞内聚合物通过合成与降解影响胞外聚合物的合成与降解,形成竞争状态,从而影响活性污泥的絮凝状况和沉降性能。课题主要研究胞内聚合物(糖原和PHB)和胞外聚合物(糖原和蛋白质)在活性污泥曝气过程中的合成与降解,及其对活性污泥性能的影响。试验采用5个序批式反应器培养活性污泥,以葡萄糖,乙酸钠,葡萄糖和乙酸钠混合物为培养基,考察了胞内聚合物和胞外聚合物在不同絮凝和沉降性能的活性污泥中的合成与降解。试验利用葡萄糖、乙酸钠作为碳源培养活性污泥形成糖原和PHB,发现在以葡萄糖为底物的条件下,在曝气开始的3h内约有15.2%被降解的COD转化为糖原;而在以乙酸钠为底物的情况下,在曝气初始的3h内约有14.4%被降解的COD被转化为PHB。曝气过程中胞内聚合物积累后及时降解有利于活性污泥的絮凝和沉降。试验还发现,胞外聚合物的过多积累会影响活性污泥的絮凝,沉降性能变差。胞内聚合物和胞外聚合物存在竞争生长。在曝气过程中胞内聚合物与胞外聚合物和合成与降解同时进行,胞内聚合物与胞外聚合物形成量的差距,都将有利于活性污泥表现出良好的絮凝和沉降性能。更多还原

【Abstract】 To environment engineers, activated sludge process is the most popular process in water treatment. In this process, sludge settling and mud-water separating is a committed step if we want to get a perfect result. To gain a good settleability, good activated sludge floc must be formed first of all. So far, there have been a lot of studies and results on the mechanism of the formation of floc, but none of these can summarize all case because of the complex component and structure of the activated sludge, it needs a further study to perfect them.Intracellular polymers (ICPs) are storages of carbon source and energy in bacteria, including glycogen, PHB, polyphosphate, sulfur globules, etc. Extracellular polymers (ECPs) are materials enclosed the cell membrane, including polysaccharides, protein, nucleic acids, lipoid, humus, fibre, etc. It’s considered that these polymers don’t have direct relation in biosynthesis, but from the type of medium, synthesis and degradation, they have relation. Especially in the aspect of the activated sludge’s flocculability and settleability, ICPs’synthesis and degradation impacted ECPs’synthesis and degradation, forming a competition, accordingly impacted the flocculability and settleability of the activated sludge.This study on the biosynthesis and degradation of ICPs (glycogen and PHB) and ECPs (glycogen and protein) during the aeration was carried out to get a better insight in their influence on the activated sludge’s performance. With glucose, acetate, glucose and acetate together as substrates respectively, five sequencing-batch-reactors (SBR) of different activated sludge’s performance were utilized to investigate the biosynthesis and degradation of ICPs and ECPs. The two ICPs were observed with glucose and acetate as substrates respectively, indicating that about 15.2% of COD translated into glycogen with glucose as substrate, and 14.4% of COD translated into PHB with acetate as substrate. It was important for a good settlement performance that accumulated ICPs were degraded in time. Besides ICPs, overabundance of ECPs would cause deterioration of the settlement performance of the activated sludge. These was a competition growth between ICPs and ECPs as well as their great quantity gap更多还原