【作者】 张颖；

【导师】 王磊；

【作者基本信息】 西安建筑科技大学 ， 建筑与土木工程， 2014， 硕士

【摘要】 膜生物反应器(MBR)作为一种新型、高效的水处理技术，具有巨大的优势和应用前景,因此受到广泛关注。将传统的生物处理工艺与膜分离技术相结合，从而实现城市污水的再生利用，是污水厂升级改造最常用的技术之一。但是传统生物处理工艺存在很多问题，并且膜作为MBR系统的核心，其使用寿命缩短和膜污染速度快等问题也将对整个MBR系统运行及其成本产生巨大影响，因此，针对MBR工艺进一步研制与开发低成本、高性能的膜具有十分重要的现实意义。本论文主要研究了以PET编织管为内支撑层，以PVDF为膜基材、PVA为亲水化改性剂，利用自主研发的涂覆-浸没凝胶相转化法制备得到具有高强度的PVDF-PET编织管改性复合膜，考察了编织管的参数及PVA浓度对改性复合膜性能的影响。分析膜的表面及截面结构，评估膜的纯水通量、平均孔径、孔隙率、通量衰减速度，并通过考察改性复合膜对二级出水中颗粒物及有机物的去除效果，优化得出最优配比浓度。将自制复合膜选出性能最优者制成帘式膜组件，组建倒置A2/O MBR系统，常温下处理模拟生活污水，考察系统对COD、氨氮、总氮、总磷及浊度的去除效果以及膜性能的变化，从宏观及微观不同角度分析膜污染的主要因素，为提高膜性能，实现膜的工业化使用及进行污水厂的升级改造提供参考。研究结果如下：（1）将PVA作为亲水化改性剂对自制PVDF-PET编织管复合膜进行了亲水化改性，结果表明：随PET编织管外径增大或编织目数减少，复合膜纯水通量、平均孔径都有显著的提高，而孔隙率却降低，当编织管外径为2.1mm，目数为45时，复合膜的纯水通量达1516L·m-2·h-1，孔隙率达61.6%。随着PVA浓度的增加，膜纯水通量上升，孔隙率、平均孔径增大，复合膜表面从大量致密的微孔逐渐变为大孔，孔间连通度增大，在PVA浓度为4%时，膜表面孔分布更为均匀、密集，膜通量1065L·m-2·h-1、孔隙率60.3、平均孔径104nm的数据整体最优；且复合膜对浊度具有很好的去除效果。（2）将亲水化改性后性能最优的膜制成帘式膜组件用于倒置A2/O MBR中，对其第一污染周期内处理效果及跨膜压差进行考察，结果显示：倒置A2/O MBR系统对城市污水处理效果良好，在不同混合液回流比条件下COD、氨氮、总磷等去除效果较好，均大于90%、95%、80%。回流比对总氮的去除效果有一定影响,回流比为100%时去除率较低，当回流比从100%增加至300%时，去除率相应增大。并且复合膜以12±0.5L/(m2·h)通量运行，运行时间19.2h/d，40天内未对膜进行任何清洗的情况下，跨膜压差始终小于8kPa，自制的复合中空纤维膜具有很好的抗污染能力。（3）工况三运行周期结束后对膜表面污染物质及反应器内环境进行分析，结果表明：反应器内松散的胞外聚合物（LB）对膜有机污染影响最大，同时经过AFM微观分析可知LB与膜之间结合力为最大。（4）反应器多工况多周期运行，对反应器内环境变化对膜污染的影响进行分析，结果显示：运行过程中，膜污染速度与反应器微环境变化关系密切，不同工况下运行过程中膜污染速率不同，但均较小。更多还原

【Abstract】 MBR attracted much attention these years as a new and efficient water treatmenttechnology, Has great advantages and application prospect. Combination the traditionalbiological treatment process with membrane separation technology, to realize therecycling of municipal wastewater, is the most commonly used technology to treatmentsewage. But it exists a lot of problems in the traditional biological treatment process,and as the membrane is the core of the MBR system. It’s life and the fouling rate is veryimportant to the MBR system. So it is very important to improve the MBR process anddevelopment a Low cost and high performance membrane.This paper mainly studied the PVDF-PET woven tubal hollow fiber compositemembrane were prepared using PET woven tubal for support layer, PVDF for film basematerial and PVA for hydrophilization modifiers. The effect of the parameters of woventube, PVA concentration in casting solution on membrane performance and the relevantproperty on filter municipal secondary effluent were investigated. Analysis themembrane surface and the cross section structure, evaluation of membrane water flux,average pore diameter and porosity, flux attenuation speed, and through theinvestigation of modified composite membrane for secondary water particles andorganic matter removal efficiency, optimize it is concluded that the optimal ratio ofconcentration. Get the optimal ratio of the concentration. Production shade typemembrane module use homemade composite membrane, then formation inverted A2/OMBR system to treatment simulated sewage in normal temperature. Investigatedremoval efficiency of COD, NH3-N, TN, TP, the variation of the TMP and the change ofthe membrane performance. From the macroscopic and microcosmic analysis the main factors of membrane fouling. Provide a reference for the sewage plant rebuilding.The results of the study are as follows:（1） when outside diameters（OD）of the PET woven tubal is increased or the meshis decreased, the water flux and average pore diameter of composite membraneincreased dramatically, while the porosity decreased. When OD was2.1mmmesh was45, the water flux was1516L·m-2·h-1, the porosity attained61.6%.And with the increase of PVA concentration, the water flux, average porediameter and the porosity of composite membrane increased, meanwhile theholes in the surface of composite membrane from tiny to large. When PVAconcentration was4%，the composite membrane shown the best performance.（2） The inverted A2/O MBR system has good removal efficiency for urban sewage.COD, ammonia nitrogen and total phosphorus removal effect is good at thecondition of different reflux ratio. Respectively above90%、95%、80%. Whenthe reflux ratio at100%, the removal efficiency of total nitrogen is low, butwhen it between100%-300%, with the ratio increase, the removal efficiencyrise. In the process of operation, although the membrane operation at flux12±0.5L·m-2·h-1, the TMP keep under8kPa, The study showed thathomemade composite hollow fiber membrane can operation at high flux andlow pressure in membrane bioreactor, which has a good ability to resistpollution and showed a good effect on particles rejection.（3） Analysis about the performance of the membrane fouling shows that the looseEPS contribution the biggest effect on membrane organic pollution, at the sametime, through the AMF microscopic analysis, the adhesion force between LBand membrane is the maximum.（4） Analysis about the environment changes in the reactor shows that Membranefouling rate is closely related to the micro reactor environmental change, theresults showed: in the process of running, the membrane fouling rate is close toreactor micro environmental changes, and different operating conditions ofmembrane pollution rate is different, but are smaller.更多还原