Research and applications of membrane bioreactors in China: Progress and prospect

In the past 15 years, remarkable progress has been achieved on the research and commercial applications of membrane bioreactor (MBR) technology in China. The objective of this paper is then to critically review the research achievements and to specifically present commercial applications of MBR in China. A total of 722 scientific papers published in peer-reviewed journals (600 Chinese papers and 122 English papers) written by Chinese authors from 1991 to 2006 and 254 full-scale MBR plants constructed in China were used as the analysis database. The number of articles published in journals together with organizations involved in MBR research saw a significant increase from 2001 to 2006, and much research progress was made during this period. From geographic distribution of these studies, it was found that the majority of the studies were carried out in North China, East China and North-East China. The research mainly focused on biomass separation MBR (BSMBR) with limited studies on extractive MBR (EMBR) and membrane aeration bioreactor (MABR), etc., and research contents included MBR configuration and type, membrane material and module, membrane fouling and control, characteristics of various wastewater treatment and other aspects like gas removal and microbial fermentation, etc. For commercial applications in China, a total of 254 MBR plants for municipal and industrial wastewater treatment were constructed by a lot of home-grown companies such as Tianjin Motimo Membrane Technology Co., Ltd. and Beijing Origin Water Technology Co., Ltd. and overseas-funded companies like Toray (Japan), Zenon (Canada), Mitsubishi-Rayon (Japan), etc. MBR plants with large treatment capacity will be built in future especially in North China due to the great need of water reclamation and reuse. Potential areas of MBR application include surface/drinking water treatment, gas diffusion and removal, membrane assisted fermentation for biological substance transformation and production, etc.     

MBR module design and operation

Membrane Bioreactor (MBR) technology is widely accepted today for wastewater treatment providing superior effluent quality, opportunities for water reuse, smaller footprint, and better process control. In the following paper, the development and application of hollow fibre submerged membrane modules in Membrane Bioreactors will be discussed. Early MBR systems used tubular cross flow micro-filtration (MF) or ultra-filtration (UF) membrane modules but the huge energy demand for cross flow technology limited it to heavily polluted niche applications. In the late 80’s the development of submerged membrane technology reduced the energy consumption by using aeration to induce a cross flow and withdrawing purified water by slight vacuum allowing the adoption of MBR technology to more conventional applications. Based upon the m² of membrane area sold/used worldwide, hollow fibre membrane technology is today the most successful submerged MBR technology.     

Survey of MBR market: Trends and perspectives in China

Membrane bioreactor (MBR) has gained considerable attention for wastewater treatment and reuse in China in the last two decades. Comparing with the global MBR market, which has an average annual growth rate of 10.9%, the average annual growth rate in China is nearly 100% in recent years. In the past 10 years, publications on MBR researches and applications for wastewater treatment have increased sharply. Over three hundred MBR plants have been successfully applied into practice for different wastewater treatments, such as municipal wastewater, bathing wastewater, restaurant wastewater, landfill leachate, hospital wastewater, petrochemical wastewater and high-concentration industrial wastewater. These plants have capacities ranging from 10 to 100,000 m³/d, among which over 12 MBR plants have capacities exceeding 10,000 m³/d. The largest MBR plant, i.e. Beijing Kunyu River WWPT, which has a capacity of 100,000 m³/d for municipal wastewater treatment and reuse, was constructed in Beijing by Origin Water Technology Co., Ltd. The largest MBR plant for industrial wastewater treatment was located in Tianjin and installed by Motimo Membrane Inc., which has a capacity of 30,000 m³/d. The largest MBR application for industrial sectors was petrochemical wastewater treatment, and over ten MBR plants each exceed a capacity of 5000 m³/d. In South-east China, the constructed MBRs are mostly involved in the high-strength industrial wastewater treatment while in North China MBRs mainly focused on municipal wastewater treatment and reuse.For an MBR commercial application in China, MBR plants were constructed by a lot of home-grown companies such as Tianjin Motimo Membrane Technology Co., Ltd., Beijing Origin Water Technology Co., Ltd. and Omexell Environmental Engineering Co., Ltd. and overseas-funded companies like Zenon-GE and CNC-Simens. Origin Water occupies the majority of the MBR market in China, whereas CNC-Simens and Zenon-GE have a larger number of installations in other parts of China. MBR unit key suppliers in China are Zenon (Canada), Mitsubishi-Rayon (Japan), Toray (Japan), Kubota (Japan), Norit (Netherlands), Motimo (China) etc.Due to more stringent regulations and wastewater reuse strategies, it is expected that a significant increase in MBR plant capacity and a widening of application areas will occur in the future.     

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...     

An integrated wastewater treatment and reuse concept for the Olympic Park 2008, Beijing

In a Sino-German research project, a joined developed sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008. The concept combines advanced technological processes like membrane bioreactors, specific phosphorus (P) adsorption columns and ultrafiltration (UF) with nature-based treatment processes like wetland and bank filtration mechanisms. The project’s approach is not only to comply with the reclamation requests of the Olympic Green 2008, but also to give an example for better, adapted and energy efficient reuse applications throughout China. The study shows that fixed-bed granular ferric hydroxide (GFH) adsorbers after a membrane bioreactor (MBR) can maintain a total phosphorus (TP) concentration of <0.03 mg L⁻¹. A low P concentration will be necessary to control eutrophication in the artificial Olympic Lake filled with treated wastewater. With an adsorption capacity of approx. 20 mg g⁻¹ d.m. at a corresponding equilibrium concentration of 1 mg L⁻¹ P, GFH reaches long operation times and can be repeatedly regenerated by caustic solutions with an efficiency of 50%. Apart from scenic impoundments, treated wastewater will be used for irrigation and toilet flushing. The latter requires a superior quality that will be delivered by low pressure UF treatment after lake (bank) filtration. A crucial reduction of fouling potential for dead-end UF is expected.     

The study of pathogenic microbial communities in graywater using membrane bioreactor

Wastewater originating from any source in the residence except for the toilet is defined as graywater. If graywater is treated appropriately, it can be used as reused water. However, wastewater reclamation carries certain health risks, and hence this study is an analysis of pathogenic microorganism and microbial communities in treated graywater for the reuse of water treated by MBR. To reuse graywater, MBR system of a lab scale was constructed with sediment, anaerobic, anoxic and oxic reactors. In the oxic reactor, a submerged MF (pore size is 0.45 μm) membrane was installed to maintain activated sludge biomass. For the quantification of pathogenic organisms, a standard spread plate method was modified using the selective medium plates. Analysis of 16S rDNA was conducted to detect microbial community. Pathogenic microorganisms such as Escherichia coli, Coliform, Staphylococcus aureus and Salmonella were detected in effluent. According to analysis of phylum and class levels, species of microorganism become simplified through membrane. This suggests that the MF membrane in the MBR system could not perfectly remove microorganisms and further research in diverse pathogens is needed for wastewater reclamation.     

Sustainability and membrane processing of wastewater for reuse

Sustainability has various meanings in the context of water reclamation and reuse. In one sense it acknowledges that to sustain our water supplies we must develop technologies that can efficiently reclaim wastewater to augment natural supplies. Membrane technology is playing a vital role in this application. However a largely unasked question is how well do the membrane technologies we use and the way we operate them stand up to scrutiny based on ‘sustainable development’ criteria? Finally at the technical and operational level we have the age-old problem of fouling and its impact on ‘sustainable’ long-term operation. This paper addresses the three levels of sustainability in the context of membrane technology and water reclamation.     

膜生物反应器处理生活污水的实验研究

对膜生物反应器连续运行期间的处理效能、膜污染情况进行了实验研究,分析并进行了膜清洗实验。膜生物反应器对COD、NH3-N都有很好的去除效果,出水水质达到生活杂用水水质标准。膜污染的发展先后经历膜孔阻塞,形成凝胶层、滤饼层等阶段。研究认为对膜进行清洗应以机械清洗为主。     

MBR和BAF用于城市污水深度处理的工艺特性比较

采用膜生物反应器(MBR)和曝气生物滤池(BAF)2种工艺分别对以生活污水为主的城市污水进行深度处理,以达到污水回用的目的.中试结果表明,在平均水温仅为5℃的情况下,MBR工艺的处理效果明显优于BAF,MBR_4~+工艺对COD、BOD＿5、NH_4~+-N和TP的去除率分别可以达到75%、92%、95%和90%,,而BAF对COD、BOD_5、NH_4~+_N和TP的去除率仅为70%、78%、29%和82%.经核算,MBR和BAF的污水处理运行费用分别为0.82元·m~(-3)和0.55元·m~(-3).与BAF相比,MBR具有处理效果优良、出水稳定、占地面积少,且维护管理方便等特点,因此,在以污水回用为目的的实际工程中推荐采用MBR工艺.     

膜生物反应器的设计及运行优化

膜生物反应器(MBR)是集生物降解和膜分离于一体的高效的新型水处理技术。膜生物反应器运行的经济性及处理废水的效率决定于膜生物反应器设计及运行参数的的合理性。文章从膜生物反应器的设计及运行参数优化方面予以综述。     

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.     

膜生物反应器的优化设计

膜生物反应器(MBR)在城市污水和工业废水的处理中受到了越来越多的重视。但目前限制其广泛应用的一个主要的障碍就是膜污染。在过去的几年中,关于膜污染的文章大量出现,它们详细阐述了膜污染的形成机理,并对减缓膜污染的措施进行了论述。本文是在总结以往研究的基础上,分析膜污染的形成原因并对膜生物反应器中减缓膜污染的方案提出优化设计。     

应用膜生物反应器处理焦化污水

膜生物反应器(MBR)是膜分离与生物反应器相结合的新型水处理技术。焦化污水是一种高浓度、难降解的工业污水，应用传统的生化方法处理焦化污水存在费用大、效率低的缺点。作者采用一体浸没式膜生物反应器处理焦化污水，调整合适的操作参数，污水中主要污染物COD、NH2-N的去除率分别达到80％、98％以上，操作简单，出水水质稳定，且远好于国家一级排放标准，取得了良好的效果，有一定的推广意义。     

膜生物反应器(MBR)技术及其工程应用探讨

膜生物反应器(MBR)废水处理技术开发始于20世纪90年代,近年来MBR技术的应用在世界上维持着每年高于10%的增长率。随着对水资源利用水平要求的不断提高,我国已经成为世界上MBR工程应用增长最快的国家。特别是2005年以来,处理能力5 000m3/d以上的新建大中型MBR项目均保持大于100%的年增长率。作者介绍了膜生物反应器(MBR)污水处理技术工程应用的主要类型及特点,总结了膜污染的机理、主要影响因素及当前工程上对膜污染的主要控制手段,给出了当前几种典型的生活污水及工业废水MBR工艺的工程应用的技术经济情况,显示出MBR工艺的应用前景。     

MBR技术在制药废水处理的应用

制药废水通常属于难降解的高浓度废水,具有组分复杂、有机物浓度高、毒性大等特点。膜生物反应器（Membrane Bioreactor,MBR）技术是膜分离技术与生物处理技术有机结合的新型废水处理技术,对于制药废水处理有着独特的优势。文章描述了MBR的分类及组成,归纳了MBR在制药废水处理的优势,并列举了MBR在生物制药、化学制药及中成药制药废水处理的多个实例,最后对MBR在制药废水处理领域的发展前景进行了展望。     

膜生物反应器在废水处理中的应用

膜生物反应器 (MembraneBio -Reactor ,MBR)是一种传统活性污泥法的改进技术 ,它应用于给水和废水处理的研究发展过程。介绍了膜生物反应器的发展状况、结构形式、优点和应用领域。     

膜生物反应器处理印染废水工艺条件的研究现状

膜生物反应器(MBR)是近年来发展的废水处理新技术,其对印染废水有着较好的处理效果,在印染废水处理方面具有广阔的应用前景.本文概述了MBR在印染废水处理方面的研究和应用,重点阐述了MBR处理印染废水的各个工艺条件及其对出水水质和膜污染的影响,并对MBR应用于印染废水处理的前景进行了展望.     

Integrated concepts in water reuse: managing global water needs

Communities across the world face water supply challenges due to increasing demand, drought, depletion and contamination of groundwater, and dependence on single sources of supply. Water reclamation, recycling, and reuse address these challenges by resolving water resource issues and creating new sources of high-quality water supplies. The future potential for reclaimed treated effluent is enormous. Although water reclamation and reuse is practiced in many countries around the world, current levels of reuse constitute a small fraction of the total volume of municipal and industrial effluent generated. In addition, to meet their growing water supply needs, communities are considering other non-traditional sources of water such as agricultural return flows, concentrate and other wastewater streams, storm water, co-produced water resulting from energy and mining industries, as well as the desalination of seawater and brackish groundwater. Water reuse provides a wide range of benefits for communities, which translates into creating immense value for the public and the environment. The benefits of water reuse, however, can be difficult to quantify and often go unrecognized. One of the most significant benefits of water reuse is the value created by the inclusion of water reuse in integrated water resources planning and other aspects of water policy and the implementation of water projects resulting in the long-term sustainability of our water supplies. These integrated concepts, which involve the convergence of diverse areas such as governance, health risks, regulation, and public perception, also present a significant challenge to water reuse. These complex connections can assert equal influences on both the benefits and challenges associated with water reuse. In addressing these complex integrated issues, a number of significant barriers and impediments to the widespread implementation of water reuse projects arise. Numerous examples exist of barriers experienced by current water reuse projects around the world, including: the need for innovative technologies, technology transfer, and novel applications; the need for public education and increased public acceptance; better documentation of the benefits of water reuse; the lack of available funding for water reuse projects; working with the media; and the need for support by regulators and politicians. Integrated concepts can also be factors in a number of trends affecting water reuse globally. Current trends include addressing emerging pollutants of concern, the use of advanced wastewater treatments including membranes, indirect potable reuse, public perception, understanding the economics of water reuse, groundwater recharge and aquifer storage and recovery, salinity management (including concentrate disposal), increase in the use of “alternative sources”, environmental or natural system restoration, innovative uses of nonpotable water reuse, and decentralized and satellite systems. Since these trends are emerging developments in the field of water reclamation and reuse, there are a number of research needs associated with these topics. Research is needed to better understand the issues, to develop innovative technologies, and to develop tools and other assistance for communities and water agencies to implement successful water reclamation and reuse projects.     

膜生物反应器在PTA废水深度处理中的应用

在PTA废水深度处理工艺中,膜生物反应器具有较高的浊度、COD的去除率,出水水质较好,在冲击性试验中也表现出良好的工艺稳定性。通过合理设计膜组件的结构和选择恰当的运行方式,可减少膜污染,延长膜清洗周期。     

A Review of Membrane Fouling in MBRs: Characteristics and Role of Sludge Cake Formed on Membrane Surfaces

Abstract

Membrane bioreactor (MBR) has been deemed to be a promising technology for wastewater treatment and reclamation; however, the MBR filtration performance inevitably decreases with filtration time attributed to the deposition of soluble and particulate materials onto and into the membrane under the interactions between activated sludge components and the membrane. Cake layer formation on membrane surfaces has been a major challenge in the operation of MBRs under supra-critical flux operation, and/or caused by uneven distribution of aeration intensities, etc.; however, it was argued that a thin cake layer might improve filtration operation by some researchers. This paper provides a critical review on the formation mechanisms, properties, the role of sludge cake in membrane filtration, and the corresponding strategies of controlling cake fouling in MBRs. Drawbacks and benefits of the formation of sludge cake were also discussed in order to better understand the characteristics and role of sludge cake formation in MBRs.