混凝超滤组合工艺的性能优化及调控原理 | |
Alternative Title | Performance Optimization and Control Principle of Coagulation Ultrafiltration Combined Process |
丁燕燕 | |
Subtype | 硕士 |
Thesis Advisor | 曲久辉 ; 马百文 |
2019-06 | |
Degree Grantor | 中国科学院生态环境研究中心 |
Place of Conferral | 北京 |
Degree Name | 工学硕士 |
Degree Discipline | 环境工程 |
Keyword | 混凝 沉淀 超滤 混凝 超滤, 膜污染行为, 影响 要素 临界沉淀时间 Coagulation Se Dimentation Ultrafiltration, Coagulation Ultrafiltration, Membrane Fouling Behavior, Influenc e Factors, Critical Settling Time |
Abstract | 混凝超滤组合工艺以其 优异的性能逐渐应用 在 实际 饮用水处理 工程 中 但滤饼层引起的膜污染始终是 影响 该工艺的 瓶颈 。与混凝 沉淀 超滤工艺(长流程)相比, 往往认为 直接混凝 超滤(短流程)工艺 中 膜池内絮体粒径大、滤饼层疏松,膜污染程度更低。 然而, 核心 问题是短流程膜工艺中 滤饼层厚度、结构等 理化 性质 均 深刻影响着膜表面污染负荷 ,是否存在 临界沉淀时间 影响 混凝 超滤组合工艺的运行效能 。 基于此 以南水北调水(北京段)为原水, 系统研究 了 长 、短流程膜工艺 运行效能及调控机制。 研究证实 混凝 超滤组合工艺 存在 “临界沉淀时间”,使得 长 流程 工艺运行效能优于短流程 (水温 20 30 o C )。 以氯化铁为混凝剂 时 当沉淀时间小于 30 min长流程膜工艺运行 12 d 导致的 膜污染程度较 短流程膜工艺 严重,此时长流程膜工艺引起的跨膜压差( TMP )高达 19.2 kPa ,短流程膜工艺引起的跨膜压差为 7.05kPa 。 然而 随着沉淀时间增加,膜表面污染负荷降低, 当沉淀时间为 60 min 时,长流程膜工艺 导致的 膜污染程度优 于短流程膜工艺, 此时长流程膜工艺 TMP 降低至 5.8 kPa 。 与铁盐混凝剂相比, 铝盐混凝剂水解絮体疏松,引起的膜污染程度较低,但也存在 “临界沉淀时间”。 以氯化铝为混凝剂时, 运行 12 d 且沉淀时间分别为 0 、 10 、 30 、 60 min 时, TMP 分别增至 3.9、4.4、3.5、2.5、1.2 kPa。由于铁盐水解絮体密实且不均匀,膜表面滤饼层形貌及结构受沉淀时间影响较大,“临界沉淀时间”较铝盐混凝剂长。 |
Other Abstract | The coagulation ultrafiltration combin ed process is gradually applied in a ctual drinking water treatment project with its excellent performance but the membrane fouling caused by the cake layer is always the bottleneck affecting the process.Compared with the coagulation sedimentation ultrafiltration process (long process), it is often considered that the direct coagulation ultrafiltration process (short causes lower membrane fouling owing to the large floc size in the membrane cell and the loose cake layer degree is lower. However, the core problem is that During the operation of the membrane process the water temperature changed periodically with the season. When the water temperature was low er (10 20 o C), the pore size of the ultrafiltration membrane was reduced, so that the total amount of pollutants reaching the membrane surface bec a me the main ca use of the membrane surface pollution load. The longer the settling time, the less the amount of contaminant reaching the surface of the membrane, and the lower the surface contamination load on the membrane. Therefore, compared with the long process, the degree of membrane fouling caused by the short process was always more serious, and there is no “ critical settling time” When ferric chloride was used as a coagulant and the settling time was 0, 10, 30, 60 mi n, the TMP increased to 13.5, 11.5, 10.0, and 7.2 kPa after 12 days of operat ion, while the TMP increased to 13.5, 8.8, 8.5, and 8.3 kPa with aluminum chloride b ecause the hydrolyzed flocs were looser. |
Pages | 80 |
Language | 中文 |
Document Type | 学位论文 |
Identifier | http://ir.rcees.ac.cn/handle/311016/42275 |
Collection | 环境水质学国家重点实验室 |
Recommended Citation GB/T 7714 | 丁燕燕. 混凝超滤组合工艺的性能优化及调控原理[D]. 北京. 中国科学院生态环境研究中心,2019. |
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