中国科学院生态环境研究中心机构知识库
Advanced  
RCEES OpenIR  > 水污染控制实验室  > 学位论文
题名: 玻璃纤维编织管式膜生物反应器工艺优化研究
作者: 于艳
学位类别: 硕士
答辩日期: 2010
授予单位: 中国科学院研究生院
授予地点: 北京
导师: 樊耀波
关键词: 膜生物反应器(MBR) ; 混合液可过滤性 ; 操作参数 ; 计算流体力学(CFD)
中文摘要:       膜生物反应器(Membrane Bioreactor, 简称MBR)是污水生物处理技术与膜分离技术结合的污水处理和回用技术。它把膜分离过程与生物降解结合起来,以膜分离装置取代普通生物反应器中的二沉池、砂滤及膜过滤的组合单元,从而取得高效的固液分离效果。MBR作为一种新型高效的水处理技术,日益受到水处理界的关注。 然而膜污染、能耗以及膜更换费用高一直是限制MBR在水处理领域广泛应用的主要障碍,也是困扰我国膜技术进一步大规模推广的瓶颈问题。从环境工程的应用角度,如何提高MBR系统运行稳定性、降低成本、对MBR工艺进行优化始终是膜生物反应器研究的热点。本研究采用了实验室自行研制的新型玻璃纤维编织管式膜组件作为研究对象,这种新型膜组件具有成本低、强度高、寿命长、处理效果好等特点。为了将其进一步推广应用,本研究以提高MBR运行稳定性、降低成本、进行工艺优化作为出发点,从改善混合液可过滤性、优化操作参数、模拟系统水力学条件三方面进行了研究,特别运用了计算流体力学这一实验手段。主要研究内容及结果包括: (1)投加粉末活性炭(PAC)改善混合液可过滤性实验。通过本部分实验发现,投加活性炭后系统对COD去除率有明显增加,对NH3-N去除率影响不很明显;投加PAC对降低膜阻力起到了很大作用,且主要是降低了吸附性污染带来的膜阻力;增加了较大粒径颗粒所占的比例,微细颗粒比例下降;EPS下降,Zeta电位略有提高;投加PAC的膜表面结构污染后更为疏松。 (2)操作参数优化正交实验。通过正交实验得出结论:在实验范围内,随着污泥浓度的增加,比膜通量存在先增加后减小的趋势,污泥浓度存在一个最优值;随着温度的增加,比膜通量基本呈线性增加;随曝气流量的增加,比膜通量也呈现先增长后下降的趋势,存在最佳值;对比膜通量影响大小的顺序为:污泥浓度、温度、曝气流量;在实验范围内得出的操作参数优化组合为A2 B3 C2。 (3)水力学条件CFD模拟实验。通过计算流体力学(CFD)中的Fluent软件,对膜生物反应器内流场和流态进行了模拟,定量给出了其流速与剪切力的分布,并与实验测得的流速值和停留时间分布函数相比较,发现与模拟结果相吻合;研究了膜组件距离反应器底部不同距离时的水力学情况;对比了膜生物反应器中玻璃纤维编织管式膜组件与平板膜组件由于构型不同所造成的水力学条件差异。结果表明,从雷诺数和质量流速率参数分析,玻璃纤维编织管式膜组件的水力学条件更好,更有利于膜污染的防治;探讨了单个与多个曝气器情况下的流速分布,结果表明后者流速分布更为均匀。由本文研究结果可知,计算流体力学是可应用于MBR及其膜污染控制研究的有力工具。
英文摘要:        Membrane Bio-reactor (MBR)is an up to date waste water treatment technology coupled the biological process directly with membrane unit. The membrane unit of MBR can play a competent role to replace the traditional process unit in waste water plant such as secondary sedimentation tank, sand filter or the one of both above combined with ultrofiltrtion or microfiltration membrane. MBR has a high-efficiency effect of solid-liquid separation. As a new type of wastewater treatment technology, MBR has gained more and more worldwide attraction. However, membrane fouling, high energy consumption and membrane replacement cost are main obstacles hindering the further development and application of MBR. How to improve the stability of process, reduce cost and optimize the operating parameters of MBR system is also a hot subject in application of MBR in environmental engineering. This study, which was based on a new glass fiber flat grille membrane module, took improving stability of process, reducing cost and optimizing operation as a target, and carried on several experiments in three aspects: improving filterability of mixed liquor, optimizing operating parameters and simulating hydraulic conditions of MBR with the art computational fluid dynamics (CFD). The performance and the results of this research are given as follows: (1)Improving filterability of mixed liquor with PAC. It was proved that COD removal increased apparently, while NH3-N removal didn’t after adding PAC to the MBR system. And PAC could reduce membrane resistance effectively, especially for the absorption resistance. Moreover, it could increase the proportion of large particals, and make descent of EPS and increasement of Zeta potential. By adding PAC into the system, structure of membrane surface was looked looser. (2)Orthogonal experiment to optimize the operating parameters of MBR. It was concluded that the membrane flux would increase firstly then decreased as MLSS increased, so there would exist an optimal concentration of MLSS. And the membrane flux had a linear increase as temperature increased. Moreover, the membrane flux increased firstly then decreased as aeration intensity increased, so there was also an optimal intensity of aeration. The order of influence on membrane flux is MLSS, temperature and aeration intensity. And there was an optimal operating condition A2 B3 C2. (3)Hydraulic simulation of MBR with Computational fluid dynamics. Hydrodynamics of MBR system and its contour of velocity and wall shear stress were simulated with computational fluid dynamics (CFD). The simulation results were found in accordance with experiment results by comparing both the velocity distribution and hydraulic residence time distribution. Different hydraulic conditions were obtained by changing the distance between the membrane module and aerator. Due to different configurations, it was proved that hydraulic conditions of MBR with glass fiber tubular membrane modules were better than that with flat membrane modules for membrane fouling control by comparing both of the Reynolds number and mass flow rate. Moreover, the distribution of velocity was more homogeneous in the system with four aerators than that with only one aerator. From the research results, it could be said that CFD is a powerful tool to be used for hydrodynamic study in MBR and its membrane fouling control.
内容类型: 学位论文
URI标识: http://ir.rcees.ac.cn/handle/311016/35021
Appears in Collections:水污染控制技术研究室_学位论文

Files in This Item:
File Name/ File Size Content Type Version Access License
玻璃纤维编织管式膜生物反应器工艺优化研究.pdf(1348KB)学位论文--限制开放 联系获取全文

Recommended Citation:
于艳. 玻璃纤维编织管式膜生物反应器工艺优化研究[D]. 北京. 中国科学院研究生院. 2010.
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[于艳]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[于艳]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Copyright © 2007-2018  中国科学院生态环境研究中心 - Feedback
Powered by CSpace