一体式膜生物反应器膜污染研究

膜生物反应器(MBR)是一种新型污水处理器,对生活污水处理效果显著,在使用过程中不可避免地会产生污染。为此,对膜生物反应器处理模拟生活污水的膜污染和清洗方法进行了研究,通过红外光谱分析了活性污泥性质的变化,利用扫描电镜分析了中空纤维膜表观结构的变化,探讨了膜污染的机理。结果表明,细菌滋生和污泥沉积造成了膜污染,泥饼层阻力占膜总阻力的89.86%,是膜污染的主要组成部分,水力清洗结合化学清洗可以很好地恢复膜的比通量。     

浸没式膜生物反应器膜污染研究现状

简要分析了浸没式膜生物反应器(SMBR)中膜污染的机理.在文献和现场考察的基础上,对膜材料、混合液特性、操作参数与条件、膜的清洗与再生等几个主要方面的研究现状进行了分析和综述,指出目前研究的不足在于缺乏反应器结构优化及反应器内流场优化方面的研究.     

浸没式厌氧双轴旋转膜生物反应器的膜污染特性研究

试验研究了浸没式厌氧双轴旋转膜生物反应器处理啤酒废水时膜的污染特性.试验分析了膜阻力分布和膜污染速率及稳定运行时膜过滤阻力随运行时间变化的阻力模型.结果表明,膜表面滤饼层很薄,膜污染很轻,膜污染速率很小.结果表明系统由膜组件双轴旋转而形成的良好水力学条件,能有效地减小浓差极化和避免污泥颗粒在膜表面的沉积.可有效控制膜污染.     

Characteristics of soluble microbial products in membrane bioreactor and its effect on membrane fouling

In this study, the accumulation and characteristics of soluble microbial products (SMP) in the mixed liquor and the effluent of the membrane bioreactor (MBR) were measured and compared. It was found that the concentration of SMP decreased when the SRT was increased from 10 days to 30 days, and then stabilized as SRT was increased to 60 days. The molecular weight (MW) distributions of SMP indicated that the SMP of larger MW (> 30 kDa) was the most abundant fraction in the MBR. The similar MW distributions of SMP in the mixed liquor and effluent implied that membrane fouling due to SMP in the initial slow fouling stage was not due to size sieving. After the MBR was operated for a period of time, only the SMP of relatively large MW (> 30 kDa) was detected in the mixed liquor. The result indicated that size sieving of SMP occurred only after a cake layer was formed on the membrane surface although the effect was not significant and only worked on larger molecules. The accumulation of hydrophilic components of SMP in the mixed liquor of the bioreactor suggested that the hydrophilic fraction (in carbohydrates) could be the major cause for membrane fouling.     

Filterability in a submerged anaerobic membrane bioreactor

Studies on anaerobic membrane bioreactor (AMBR) show high variability about filterability. Therefore, in this study, a laboratory-scale submerged AMBR (SAMBR) was operated with the aim of identifying operational conditions and sludge characteristics that influence the membrane flux. Short-term experiments applying the flux-step method resulted in values of the critical flux (Jc) variable depending on the operational condition applied in the SAMBR. The application of different parameters for the identification of Jc gave comparable results. Although the plant was operated applying different operational conditions, a rapid membrane fouling was usually observed. The applicable fluxes were between 2 and 5 L/(m² h) depending on operational conditions. Therefore, the results confirm the much lower sludge filterability in anaerobic than aerobic MBRs. Multiple regression analysis showed that the supernatant composition plays the most important role in membrane fouling.     

微生物代谢产物对膜生物反应器膜污染的影响

针对膜生物反应器（MBR）在运行过程中溶解性微生物代谢产物（SMP）及胞外聚合物（EPS）对膜污染进行研究。实验过程中对MBR内的污泥混合液进行了定期膜阻力监测。结果表明,SMP和EPS对膜过滤阻力有负面的影响。SMP中相对分子质量分布（Mw）在3～10 kDa对膜内部阻力影响显著,SMP中Mw＞10 kDa的大分子有机物及EPS浓度对膜外部阻力影响明显。通过傅里叶转换红外光谱（FTIR）检测膜表面污染物表明,EPS主要由多聚糖、蛋白质和腐殖酸组成,而污染层中的SMP主要是多聚糖和腐殖酸。     

改性PVDF膜在MBR中膜污染的研究

将聚偏氟乙烯膜磺化6 h,在TiO2胶体溶液中浸泡20 min,制得的TiO2改性膜纯水通量约为1 800L/m2·h,高出未改性膜250L/m2·h.通过膜生物反应器中膜阻力的测定,分析膜污染形成的原因,表明膜污染主要是浓差极化层及凝胶层引起的;通过活性污泥对膜污染机理的研究,判断出污泥的过滤过程严格符合沉积过滤定律.在膜生物反应器(MBR)中运行时,TiO2改性膜稳定通量高于未改性膜,总阻力低于未改性膜;通过扫描电镜分析,TiO2改性膜沉积层的厚度比未改性膜薄,表明TiO2改性膜的抗污染性能优于未改性膜.     

膜生物反应器中的膜污染及其再生

作为21世纪最具潜力的水处理技术之一,膜生物反应器受到越来越多的重视,在污水处理与回用中有着良好的应用前景,但膜污染和膜再生技术已成为制约其发展的瓶颈.介绍了膜污染的分类和机理,并从膜的性质、混合液的性质以及操作条件等方面对形成膜污染的影响因素及膜污染的防治进行了综述,同时阐述了几种常用的膜污染再生方法.     

厌氧膜生物反应器及其膜污染探析

厌氧膜生物反应器(anaerobic membrane bioreactor,AnMBR)集厌氧生物技术和膜分离技术于一体,具有高负荷、低能耗、可回收沼气和高效截留等优点,在高浓度有机废水治理领域潜力巨大。然而,国内外关于AnMBR的工程运行参数较为欠缺。此外,膜污染问题是阻碍该工艺应用推广的重要致因,故其一直是AnMBR的研究热点。本文概述了AnMBR的工艺特征以及AnMBR的结构、组合方式及其特点,指出当前外置式应用较多,内置式因其特点也逐渐引起关注;综述了AnMBR及其组合工艺在国内外的工程应用现状,指出该技术多在实验室阶段,且于工程化方面国内落后于国外;探析了膜污染机理及其影响因素(膜组件、污泥特性和操作条件等影响因素)关于膜污染的作用机制;并总结了一些控制膜污染的典型预防和控制措施,以期为相关研究应用提供参考。     

膜生物反应器中膜污染控制的研究进展

介绍了膜污染的机理及影响因素,从膜结构的选择,如膜材料、膜孔径;优化工艺、优化运行条件,如曝气强度、出水方式以及定期清洗等方面描述减缓膜污染速度,延长膜清洗周期的控制措施,为MBR在废水处理领域的发展提供一定的支持。     

不同碳源对A/O-动态膜生物反应器膜污染的影响

采用两套平行的A/O-动态膜生物反应器工艺处理市政污水,分别以乙酸钠(反应器A)、蔗糖(反应器B)为碳源,考察运行过程中不同碳源对EPS、溶解性蛋白质/溶解多糖比值、污泥粒径、Zeta电位的影响。结果表明,在运行过程中,反应器A中EPS累积量大于反应器B;A、B反应器中溶解蛋白质/溶解多糖比值分别为0.19⁰.40和0.170.40和0.17⁰.27,三维荧光图谱表明,A反应器中类蛋白荧光峰强于B反应器;反应器A中污泥粒径<10μm的微粒所占的比例以及Zeta电位均大于反应器B。以蔗糖为碳源有利于减缓膜污染。     

Viability of microbial mass in a submerged membrane bioreactor

In this study the viability of biomass in a submerged membrane activated sludge system (sMBR) which treats domestic wastewater was investigated by dealing with non-biodegradable COD, specific oxygen uptake rate and MLVSS during operation for 100 days. It was shown that the viability of biomass in the bioreactor was reduced at the 50% level because of the accumulation of inert compounds and the reduction in the activities of poor biomass. After inoculating the bioreactor again, the specific OUR increased because of young biomass entering into the bioreactor. It was shown that there was an exponential relationship between OUR and MLVSS and there was a logarithmic relationship between specific OUR and MLVSS.     

膜生物反应器中膜污染影响因素的研究进展

文章综述了膜生物反应器(MBR)运行过程中膜污染影响因素的研究现状和进展。膜污染会导致膜通量下降、系统运行成本增加等问题,是限制MBR进一步发展的瓶颈。从膜元件固有性质、膜分离操作条件以及活性污泥混合液性状等3个方面,分析了影响膜污染发展的主要因素,论述了各因素与膜污染的具体关系。各因素之间互相作用,直接或间接影响膜污染,其中膜材质、膜孔径、膜通量、曝气量、污泥组分、粒径分布(PSD)、胞外聚合物(EPS)、溶解性微生物产物(SMP)等为重要影响因素。     

Dependence of shear and concentration on fouling in a membrane bioreactor with rotating membrane discs

Rotating ceramic membrane discs were fouled with lab‐scale membrane bioreactors (MBR) sludge. Sludge filtrations were performed at varying rotation speeds and in different concentric rings of the membranes on different sludge concentrations. Data showed that the back transport expressed by limiting flux increased with rotation speed and distance from membrane center as an effect of shear. Further, the limiting flux decreased with increasing sludge concentration. A model was developed to link the sludge concentration and shear stress to the limiting flux. The model was able to simulate the effect of shear stress and sludge concentration on the limiting flux. The model was developed by calculating the shear rate at laminar flow regime at different rotation speeds and radii on the membrane. Furthermore, through the shear rate and shear stress, the non‐Newtonian behavior of MBR sludge was addressed. © 2013 American Institute of Chemical Engineers AIChE J 60: 706–715, 2014     

不同碳源对A/O-动态膜生物反应器膜污染的影响

采用两套平行的A/O-动态膜生物反应器工艺处理市政污水,分别以乙酸钠(反应器A)、蔗糖(反应器B)为碳源,考察运行过程中不同碳源对EPS、溶解性蛋白质/溶解多糖比值、污泥粒径、Zeta电位的影响。结果表明,在运行过程中,反应器A中EPS累积量大于反应器B;A、B反应器中溶解蛋白质/溶解多糖比值分别为0.19~0.40和0.17~0.27,三维荧光图谱表明,A反应器中类蛋白荧光峰强于B反应器;反应器A中污泥粒径10μm的微粒所占的比例以及Zeta电位均大于反应器B。以蔗糖为碳源有利于减缓膜污染。     

一体式膜生物反应器中料液粘度的研究

探讨了一体式膜生物反应器中料液粘度变化的原因,以及料液粘度对膜过滤阻力的影响。试验结果表明:料液粘度的增加主要因反应器中累积的高浓度胞外聚合物(EPS)所致;污泥粘度随着EPS浓度的变化而变化,二者之间存在很好的相关性(r=0.9958);污泥粘度与膜过滤阻力有较好的相关性(r=0.9006)。     

膜生物反应器中的膜污染及其调控措施

膜生物反应器(MBR)是一项高效的污水处理与回用新技术,膜污染是MBR的主要问题,它限制了MBR的推广和应用.从膜性质、操作条件和活性污泥混合液性质3方面系统论述了MBR中膜污染的影响因素,着重针对各影响因素总结减缓膜污染的调控措施.并指出采取有效、合理的调控措施可有效减缓膜污染,使其在污水处理与回用领域得到更广泛的应...     

Effect of operational parameters on sludge accumulation on membrane surfaces in a submerged membrane bioreactor

In the present study, an orthogonal array design was adopted to investigate effects of operational parameters including aeration intensity, membrane flux, suction time and non-suction time on sludge accumulation on membrane surfaces respectively at a high SS concentration of 10 g l⁻¹ and a low SS concentration of 1 g l⁻¹ in a submerged membrane bioreactor. Average transmembrane pressure (TMP) increase rate over the operation time was used to evaluate sludge accumulation. Among the four factors, membrane flux was found to influence TMP the most obviously. The effect of aeration intensity became significant only at a high SS concentration of 10 g l⁻¹. TMP increased with suction time and decreased with non-suction time. There was a critical membrane flux over which sludge particles were deposited, and accordingly, TMP increased sharply. Two zones, predicting whether sludge particles are deposited or not, could be comprehensively determined by the critical flux, correspondent aeration intensity and SS concentration. For long-term stable operation, it is suggested that a membrane bioreactor be operated in the zone with prediction of no obvious sludge deposit on membrane surfaces.     

膜生物反应器中膜污染控制技术的研究进展

膜污染是膜生物反应器(MBR)运行的必然结果,是MBR大面积推广的严重阻碍,因此研究膜污染控制技术具有重要意义。从膜污染发生前的预防和膜污染发生后的清洗2个方面,论述了常见的各种膜污染控制手段,综述了膜污染控制技术的研究现状与进展。其中膜污染的预防手段主要有膜(膜组件)固有性质的改进、操作条件的优化以及混合液性状的调控3类,而膜污染的清洗手段按是否使用药剂可分为物理清洗和化学清洗2类。综合考察MBR运行中的膜污染状况,采用合理的方法对膜污染进行控制,能够有效延长膜的使用寿命,提高MBR的实用性能。     

AHL-QS减缓膜生物反应器膜污染研究进展

首先介绍N-乙酰高丝氨酸环内酯（N-acyl homoserine lactone,AHL）型生物群体感应（quorum sensing,QS）信号分子对膜生物反应器（membrane bioreactor,MBR）膜表面形成生物膜的调节机制,通过AHL-QS信号分子细胞间的交流,可决定生物膜形成及胞外聚合物（extracellular polymeric substances,EPS）分泌;系统阐述了应用AHL-QS信号分子降解酶及淬灭剂对MBR生物膜污染的控制效果,抑制或降解信号分子可显著降低生物膜形成能力,从根本上控制膜污染。此外,针对降解酶及淬灭剂新的固定化技术在MBR中的应用也作了介绍,如磁性载体、膜表面负载、微生物-管束及多孔微球包埋细胞技术。以AHL-QS为基础的膜污染控制策略对于MBR应用前景广阔,然而该技术的工程化研究仍有待进一步深入;加强AHL-QS信号分子识别及进一步明确QS系统对微生物代谢机制的影响是该领域未来重要的研究方向。