阳离子调理剂与阳离子聚电解质联合作用于活性污泥脱水及其机理的研究.doc

上海交通大学硕士学位论文阳离子调理剂与阳离子聚电解质联合作用于活性污泥脱水及其机理研究摘 要随着生活污水和工业废水处理率的提高，污泥的产量越来越大我国污泥年产生量约为 1×107 吨/年，且随着废水处理要求的提高污泥产生量也逐年提高如何提高污泥的脱水性能，减少污泥处理费用成为当今各国一个重要的研究课题目前广泛采用的污泥脱水方法是聚电解质法，其具有絮凝沉降性能好的优点，但存在着滤饼含水率偏高等问题因此，本文以去除污泥中水为目的，合成一类污泥调理剂，不仅考察了它们对污泥絮体结构的影响（EPS、污泥絮体粒径、表面相对疏水性及污泥絮体强度），还考察了它们对脱水指标的影响（如毛细吸水时间 CST、污泥比阻SRF、污泥过滤沉降速度、污泥滤饼含水率及结合水含量）研究主要从以下两个方面展开：(1) 实验室自合成一类污泥调理剂其在固体表面作用原理是通过降低气/液界面张力、增大固/液接触角，改变污泥表面性质从而改善污泥的脱水性能研究发现：调理剂依靠静电引力和疏水组分间的缔合作用吸附在活性污泥表面随着投加量的增加，污泥表面 EPS 不断1上海交通大学硕士学位论文脱落，使污泥絮体特征发生了一系列变化：絮体粒径变小、相对疏水性增加等。

污泥絮体特征的变化直接导致污泥脱水指标的变化，当调理剂 CSC16 投加量为 0.02g/g 干污泥时，污泥滤饼含水率降低为73.9%，脱水效果非常明显，但实验也显示表面活性剂对污泥的过滤性能和沉淀性能没有显著的提高2) 结合调理剂和聚电解质于污泥脱水时的优缺点，通过投加不同比例的调理剂和聚电解质对活性污泥进行脱水，并与单独投加聚电解质对比，实验发现，调理剂作用于后，污泥絮体中大量结合水被去除，聚电解质絮凝时包裹的水不再是结合水而较易被除去两种药剂联合作用后，污泥絮体结构更致密，粒径和强度都大幅增加，过滤速度也明显提高，且当两种药剂投加量分别为 0.01g/g DS 和 0.0075g/g DS时，污泥滤饼含水率降低至 72.3%，达到了非常好的脱水效果关键词：污泥脱水，调理，Laplace-Young方程，污泥絮体结构，联合作用2上海交通大学硕士学位论文Research on the Effect and Mechanism of Teamwork of CationicConditioner and Polyelectrolyte on the Dewater ability of ActivatedSludgeABSTRACTCurrently, approximately 10,000,000 tons of sludge are producedannually in the water treatment plants of China. This amount is expected toincrease significantly due to the increasing demand for better quality water.How to enhance the dewater ability of sludge and reduce the cost of sludgetreatment becomes an important research interest in the world.For years, polyelectrolyte conditioning has been the most popularpractice for improving the dewatering property of sludge. Despite itsefficiency in sludge conditioning, there is still a large quantity of water inthe flocculating constituent of activated sludge, which leads to thedifficulty in further reducing the water content of dewatered sludge. Manyresearchers have been searching for alternatives in reducing sludge watercontent. With the purpose of removing the water in the sludge flocs, studytheir effects on the sludge flocs characteristics (such as: floc size, fractaldimension, floc strength and chemical composition of sludge flocs) and3上海交通大学硕士学位论文dewater ability of activated sludge (such as: CST, SRF, bound watercontent in sludge, settling rate, water content in filtrated cake ) study fromthe following two aspects:1. synthesize new type of conditioner,. The mechanism ofself-synthesized conditioner can be illustrated by Laplace-Young equation,in the activated sludge system, such conditioners can decrease the surfacetension between vapor/liquid interfaces, and increase the solid/liquidcontact angle, and increase the capillary radius, so that they can improvethe activated sludge dewater ability. Conditioners can be adsorbed onactivated sludge surface depending on electrostatic attraction andhydrophobic association, changing the distribution of extracellularpolymeric substances (EPS) on floc surface. With the increasing ofconditioners dosage, compositions of EPS were continuously releasedfrom the sludge surface and dissolved in the solution, which resulted in aseries of changes of the sludge flocs characteristics, including thereduction of flocs size and increasing of relative hydrophobic. Anyhow, allthe changes for the characteristics of sludge flocs directly caused thechanges of the dewatering indexes of sludge. From the experimentalresults it can be seen that conditioners can significantly lower the boundwater in sludge and the water content in filtrated cake, but no obvious4上海交通大学硕士学位论文effect on improving filterability and settle ability. When the dosage ofCSC16 was 0.02g/g dry sludge, the water content in sludge cake aftervacuum filtration dramatically decreased to 73.9%.2. Associate with the positive effects that self-synthesized sludgeconditioner and commercial polyelectrolyte acted on activated sludge,adding different doses of conditioner and polyelectrolyte in activatedsludge. With contrast to adding polyelectrolyte only, the experiments showthat when adding polyelectrolyte, the sludge flocs would re-flocculate witha great deal of water, but this water can be removed easily. When adding0.01g/g DS of conditioner and 0.0075g/g DS of polyelectrolyte, the watercontent in the remaining sludge cake after filtration decreased to 72.3%,and the sludge is more compact and dewatered comparing to the additionof one of them single at random.KEY WORDS: Sludge Dewatering, Conditioning, Laplace-YoungEquation, Characteristics of Sludge floc, Teamwork5上海交通大学学位论文版权使用授权书本学位论文作者完全了解学校有。