聚磷生物膜法磷回收研究进展

从污水中回收磷已经成为当前污水全面资源化研究领域的重要研究方向之一,聚磷生物膜法磷回收工艺因其在节省碳源、简化回收流程、提高回收效果、污泥减量化等方面的潜力,成为该领域的重要技术手段和研究热点。本文着重介绍了聚磷生物膜法磷回收的基本原理、功能微生物及其代谢特征;详细梳理了生物膜法磷回收工艺不同模式的回收思路,综合分析了不同工艺模式的技术特征和磷回收效果。此外,对聚磷生物膜系统微生物及其代谢的研究方法与技术进行了整理。文章在综合分析聚磷生物膜法磷回收研究现状的基础上,对该技术的应用前景进行了宏观展望,以期为开展聚磷生物膜法磷回收的基础研究和技术开发提供支撑。     

Zn-Fe LDHs改性石英砂生物膜体系对BDE-47的去除效果与机理

文章以四溴联苯醚(BDE-47)为目标污染物, 利用共沉淀法制备Zn-Fe LDHs覆膜改性石英砂基质, 在好氧、厌氧及两者交替条件下, 研究腐败希瓦氏菌CN32(Shewanella putrefaciens CN32) 在LDHs改性基质上生物膜形成过程及其对培养液中BDE-47的去除效果; 通过监测反应体系中Fe2+和H₂O₂浓度变化探讨BDE-47的生物及非生物去除机制。结果表明, LDHs改性不影响石英砂基质表面生物膜的形成, 但在好氧条件下, Zn-Fe LDHs石英砂改性基质对CN32电子传递链活性存在一定抑制作用, 而在厌氧条件下, LDHs改性会影响基质生物膜胞外聚合物(EPS)组成特性, 使多糖占比升高。无论在好氧还是厌氧条件下, 基质生物膜反应体系中EPS总浓度均显著高于纯菌CN32体系; 且在好氧与交替条件下, 基质生物膜的形成均显著提高反应体系中BDE-47的去除效果(约25%)。在交替条件下, 前3次循环(72h内)BDE-47的去除以基质吸附为主; 72h后, 生物膜吸附与生物降解共同发挥作用, 且LDHs改性基质在后期上升潜力更大。研究报道了LDHs改性基质生物膜形成特性及其对水相中PBDEs去除的潜力, 为强化人工湿地中PBDEs生物降解提供新思路。     

生物膜研究在生物物理研究所的兴起与发展

生物膜研究是现代生物学研究的前沿方向之一,本文对文革结束以后生物膜研究在中国科学院生物物理研究所(下称生物物理所)的兴起与发展进行了系统回顾.文革结束后,中国科学院领导了解到国外生物膜研究迅速发展的情况,迅即派遣以生物物理所杨福愉为组长,包括生物化学研究所、动物研究所、植物研究所、上海实验生物研究所等六人的代表团前往联邦德国进行考察.考察结束后院领导根据多学科交叉对生物膜研究的重要作用,组织了生物物理所、植物所、中国医学科学院、北京医科大学等单位联合申报国家自然科学基金委员会重大项目"膜脂-膜蛋白的相互作用及其在医学和农业上的应用",并获得立项.与此同时,院领导建议由中国生物物理学会、中国生化学会和中国细胞生物学会共同组织生物膜学术讨论会.首次会议于1979年3月在北京友谊宾馆举行,以后每3年召开1次,从未中断,有力地促进了生物膜研究的交流与发展.2003年举行的第200届香山会议专门组织讨论21世纪生物膜研究在中国的布局,进一步推动了生物膜研究的发展.本文还重点阐述了中国科学院生物物理研究所在生物膜研究方面所取得的代表性成果:a.金属离子通过膜脂-膜蛋白相互作用调控生物膜能量转换、物质运输及信号转导的分子机制;b.提出"克山病是一种心肌线粒体病"的重要观点;c.发现溶酶体内含有为量甚微、一般认为是消化酶的胰凝乳蛋白酶,并阐明了它通过溶酶体膜外泄后参与细胞凋亡的作用机制;d.确定了通过调控线粒体动态变化而干预肿瘤细胞迁移侵袭的新靶标.最后,特别值得一提的是,2004年,常文瑞与植物研究所匡廷云等在《自然》(Nature)发表了《菠菜中主要捕光色素复合体2.72魡分辨率的晶体结构分析》的研究论文,2005年饶子和与徐建兴等在《细胞》(Cell)发表了《猪心线粒体呼吸链复合体Ⅱ的晶体结构》的研究论文,充分标志着我国生物膜研究已在国际上占据一席之地.2004年,徐涛研究员因其在囊泡转运方面的丰厚学术积淀,作为首席科学家组织一批生物膜专家承担了国内首个生物膜973项目,这标志着国内生物膜研究开始进入一个新的发展时期.     

生物膜法和SBR法相结合处理难降解制药废水的研究

采用生物膜法和SBR法相结合的废水处理工艺处理含抗生素类等难降解的制药废水 ,对生物膜的耐冲击负荷能力、生物膜对进水可生化性的影响、生物膜对好氧SBR活性污泥性能的影响、pH对系统去除效果的影响等工艺条件进行研究 ,并通过与传统SBR处理工艺的对比试验 ,进一步揭示了生物膜法和SBR法相结合的处理工艺强的耐冲击负荷能力。     

生物膜型污水脱氮系统中膜结构及微生物生态研究进展

生物膜法污水脱氮系统主要利用生物膜中脱氮功能微生物的代谢活动去除氮素,从而达到净化水质的目的,研究脱氮生物膜的微观结构和微生物生态是揭示生物膜脱氮机理从而提高脱氮效率的重要途径.本文综述了生物膜型污水脱氮系统类型、生物膜微观结构特征及其影响因素、生物膜型污水脱氮系统内氮素传质过程、脱氮机理和生物膜数学模型等方面的研究进展.另外,本文介绍了生物膜型污水脱氮系统内生物膜脱氮功能微生物分布特征,不同生物膜脱氮系统、底物、运行条件和时间对功能微生物群落影响,及新型脱氮功能微生物等方面的研究进展,为生物膜脱氮技术的深入研究提供参考.     

从单分子到细胞的生物膜与膜蛋白研究——美国Purdue大学关于生物膜的研究计划简介

生物膜是由脂质、蛋白质和碳水化合物组成的令人惊讶的多功能“海洋” ,在生命活动中起着非常重要的作用 (如物质运输、代谢调节、分子识别、细胞免疫及激素与药物的作用 )。然而 ,我们目前对于膜的组织结构、动力学和功能等许多方面仍知之甚少。要全面阐明真核细胞的全生理过程就必须详细了解生物膜的各种性质 ,这就要求我们所用的实验手段要与现有的各种研究基因组学和蛋白质组学的方法不同 ,并寻求在多种层面上研究生物膜。本文简介以美国Purdue大学生命科学学院为主提出的从 2 0 0 3年 2月开始近 5～ 10年开展有关生物膜和膜蛋白研究的…     

细菌生物膜在农田土壤污染修复中的应用研究进展

全球农田土壤污染日趋严重。重金属、农药、微塑料作为常见的土壤污染物,已对农田生态系统与粮食安全造成严重威胁。细菌生物膜(bacterial biofilm,BF)作为分布于细菌表面的多组分聚集体,近年来已被证明在环境保护领域具有较高的应用价值。本文主要介绍了细菌生物膜的组成和功能,并对近年来细菌及其生物膜在重金属、有机物污染土壤修复中的应用及机理进行综述,展望生物膜群落结构在污染土壤中的修复潜力,以期深入理解细菌生物膜的关键作用,为挖掘更多细菌生物膜在环境保护方面的应用潜力提供理论指导。     

高脱氮活性海洋着色菌YL28生物膜特性

【背景】细菌生物膜在废水处理领域显示出良好的前景,但目前应用于海水养殖水体处理的菌株主要源自淡水菌株,存在难以适应海水高盐环境的问题。源自红树林的海洋着色菌(Marichromatiumgracile)YL28应用于海水养殖水体处理,不仅具有高效除氮能力,而且趋光贴壁能力很强。【目的】阐明海洋着色菌(Marichromatium gracile) YL28的生物膜形成特性和规律,以期为海水养殖水体生物膜反应系统的开发和应用提供参考。【方法】以生物膜和游离菌体生物量、脱氢酶活性、生物膜多糖含量和蛋白含量、无机三态氮去除活性为测定指标,在光照厌氧环境中研究海洋着色菌YL28菌株的生物膜形成规律、生物活性和脱氮效果。【结果】随着时间延长,4 000 lx光照时游离菌体生物量逐渐升高,但在稳定期前快速降低,而成膜生物量经过延滞期后逐渐升高并趋于稳定,表明培养过程中游离菌体能趋光贴壁生长并形成生物膜。在0-5 000 lx光照范围内培养4 d,低光照强度(500 lx)时成膜率(71.21%)最高,1 000-4 000 lx光照强度下成膜率虽然不是最高(54.64%-68.66%),但适宜菌体成膜,膜生物量干重达到0.60-0.80 mg/cm2。除了5 000 lx光照对成膜菌体脱氢酶活性有不利影响外,成膜菌体和游离菌体脱氢酶活性随光照强度升高而升高,而且没有明显差异。生物膜的形成会导致光反应器内部光照受限,但反应器内部游离菌体的脱氢酶活性并没有降低,由此表明,培养液中的菌体主要在生物膜及其界面生长并游离扩散至培养液中。随光照强度(1 000-5 000 lx)和培养时间(4-10 d)的变化,胞外复合物(Extracellularpolymericsubstances,EPS)中蛋白含量变异较大,多糖含量变化较小;随时间延长,蛋白含量升高,其中3 000 lx时蛋白含量最高;4 000 lx时生物膜菌体与游离菌体脱氮活性相比,单位质量菌体的氨氮和亚硝氮去除活性未受到明显影响,而硝氮去除活性有所降低。【结论】海洋着色菌YL28具有良好的生物膜形成能力,其成膜过程主要是菌体趋光贴壁生长成膜,成膜菌体具有良好的脱氮活性,这为利用生物膜系统消除海水养殖水体氮污染奠定了基础。     

生物膜法强化净化氨氮污染水体及其微生物群落解析

【目的】比较不同营养条件及挂膜方式下生物膜法对氨氮污染水体的净化效果及其功能微生物群落结构。【方法】设置空白(Blank)、自然成膜(Raw)、预附脱氮菌强化挂膜(PCC)3组生物膜反应器,利用末端限制性片段长度多态性(T-RFLP)技术和非度量多维标度(NMDS)分析方法对生物膜反应器转化氨氮过程中微生物群落结构及其演替过程进行动态解析。【结果】在C/N=1:1时,除PCC在起始阶段短暂具有较高的氨氮脱除效率外,Blank、Raw和PCC最终均表现出较低的氨氮转化效率(10%-20%)。改变C/N=2:1后,Raw和PCC对人工合成污水中NH4+-N的转化率均提高至95%以上,而且Raw与PCC的群落结构在C/N=2:1时具有较高的相似性,优势菌群主要为γ-变形菌纲(Gammaproteobacteria)、放线菌纲(Actinobacteria)和硝化螺菌纲(Nitrospira)。【结论】C/N是影响生物膜反应器氨氮去除效果及驱动生物膜反应器中细菌群落结构发生改变的重要因子。     

一株工业腐败物中魏氏柠檬酸杆菌的分离鉴定及产生物膜特性分析

【目的】分离和鉴定工业腐败物中高产细菌生物膜菌株,并明确该菌的部分产膜特性。【方法】通过微孔板结晶紫染色法对分离的菌株进行产膜能力评价,根据菌落形态、生理生化特性和16S rRNA序列的系统进化树分析进行菌株鉴定;同时利用扫描电子显微镜(SEM)和结晶紫染色法分别研究材料及温度对该菌产膜特性和能力的影响。【结果】筛选出一株高产细菌生物膜菌株,经鉴定该菌为魏氏柠檬酸杆菌;其在玻璃、不锈钢和聚氯乙烯(PVC)材料表面均能形成生物膜;温度条件显著影响产膜能力,在30°C时,菌株在PVC材料表面形成生物膜能力最强。【结论】工业腐败物中含有高产细菌生物膜菌株,并且产膜受附着物和温度影响。     

Start-up of the Anammox process in a membrane bioreactor

The start-up of an Anammox process was studied in a membrane sequencing batch reactor (MSBR) in which a submerged hollow fibre membrane module was used to retain the biomass. The reactor was seed with Anammox biomass and fed using the Van de Graaf medium. During a first operating stage, salt precipitation was observed and interfered with microbial activity and caused a decrease of the nitrogen removal rate of the reactor from 100 to only 10 mgl(-1) per day. Salt precipitation was avoided by diminishing adequately the Ca and P concentrations of the Van de Graaf medium during the last operating stage. This action increased quickly the activity of the system, and nitrogen removal rate reached up to 710 mgl(-1) per day with almost full nitrite removal. Sporadic flotation of the sludge was observed in the MSBR. The use of the membrane avoided biomass wash-out from the system. Moreover, a surprising fact was that Anammox biomass did not grow in flocs in the MSBR, but in granules. This fact showed that this kind of microorganisms have a trend to grow in aggregates. Results indicated that the use of the MSBR could be a suitable system for nitrogen removal by using the Anammox reaction.     

Simultaneous ammonium-nitrogen and copper removal, and copper recovery using nitrifying biofilm from the ultra-compact biofilm reactor

Simultaneous ammonium-nitrogen (NH(4)(+)-N) and copper removal, and copper recovery in synthetic wastewater using nitrifying biofilm from an ultra-compact biofilm reactor (UCBR) was demonstrated in batch studies, which consisted of three phases: Phase 1 for NH(4)(+)-N and copper removals, Phase 2 for copper recovery, and Phase 3 for NH(4)(+)-N removal. The results showed that more than 96.3% of copper was removed within 60min, while 60.1% of the adsorbed copper was recovered through rinsing the biofilms with 0.1mM of ethylenediaminetetraacetic acid (EDTA). The nitrifying biofilm was able to adsorb 0.245mg of copper/g of biofilms. After recovery treatment, 29.4% of copper remained bound within the nitrifying biofilms. No significant inhibitory effects towards NH(4)(+)-N removal in the presence of 0.92mg copper/L was noted in Phase 1 compared with the control test. However, lower initial pH condition in the recovery process and the accumulation of copper on the biofilm led to 50% inhibition on NH(4)(+)-N removal efficiency in the subsequent phase.     

Autotrophic denitrification via a novel membrane-attached biofilm reactor

AIMS: A laboratory-scale autotrophic membrane-attached biofilm reactor was developed to remove nitrate from drinking water. METHODS AND RESULTS: Hydrogen and carbon dioxide flowed together into the lumem side of a gas-permeable silicone tube. The gases diffused through the membrane wall to feed Alcaligenes eutrophus that formed a biofilm on the surface of the silicone tube for autotrophic denitrification. Hydrogen provided the energy source, and carbon dioxide, besides serving as the carbon source, was employed to neutralize the alkalinity from denitrification. The optimal carbon dioxide concentration in the silicone tube was between 20% and 50%. CONCLUSION: This study has demonstrated that a gas-permeable silicone tube is a convenient and efficient method to feed A. eutrophus for autotrophic denitrification. Supplying a suitable amount of carbon dioxide together with hydrogen into the silicone tube solved the problem that alkalinity formation caused during denitrification. The pH of the bioreactor was maintained at about 7 to avoid nitrite accumulation, and then the nitrogen removal rate was increased. A high specific nitrogen removal rate (1.6-5.4 g Nm(2)d(-1-1) of surface area of silicone tube) was achieved. SIGNIFICANCE AND IMPACT OF THE STUDY: In addition to combining the advantages of the hydrogenotrophic denitrification process and a membrane feeding substrate bioreactor (MFSB), this bioreactor achieved a high nitrogen removal rate and is simple to operate. It therefore is highly promising in drinking-water treatment.     

Removal of inorganic anions from drinking water supplies by membrane bio/processes

This paper is designed to provide an overview of the main membrane-assisted processes that can be used for the removal of toxic inorganic anions from drinking water supplies. The emphasis has been placed on integrated process solutions, including the emerging issue of membrane bioreactors. An attempt is made to compare critically recently reported results, reveal the best existing membrane technologies and identify the most promising integrated membrane bio/processes currently being under investigation. Selected examples are discussed in each case with respect to their advantages and limitations compared to conventional methods for removal of anionic pollutants. The use of membranes is particularly attractive for separating ions between two liquid phases (purified and concentrated water streams) because many of the difficulties associated with precipitation, coagulation or adsorption and phase separation can be avoided. Therefore, membrane technologies are already successfully used on large-scale for removal of inorganic anions such as nitrate, fluoride, arsenic species, etc. The concentrated brine discharge and/or treatment, however, can be problematic in many cases. Membrane bioreactors allow for complete depollution but water quality, insufficiently stable process operation, and economical reasons still limit their wider application in drinking water treatment. The development of more efficient membranes, the design of cost-effective operating conditions, especially long-term operations without or with minimal membrane inorganic and/or biological fouling, and reduction of the specific energy consumption requirements are the major challenges.     

A critical review of membrane crystallization for the purification of water and recovery of minerals

Membrane crystallization is an innovative concept to treat water and recover minerals from concentrates. Thus, it will also be beneficial to the existing mineral extraction industry. This process combines membrane distillation (MD) with crystallization. While MD produces water and concentrates the feed, crystalliser forms crystals from supersaturated minerals in the concentrated feed. This review covers principles of this process, factors affecting membrane crystallization for water treatment, application of membrane crystallization, resource recovery and the fouling of membrane crystallization. Membrane crystallization could recover many minerals including sodium, magnesium, barium, strontium, and lithium. However, fouling is a major challenge for its widespread implementation. Further directions for future research and development of this process are also considered with a view to the sustainable operation of the process.     

Validation of the ion-exchange membrane bioreactor concept in a plate-and-frame module configuration

The ion exchange membrane bioreactor (IEMB) is a particular case of a membrane-supported biofilm reactor, in which oxy-anions, used as electron acceptors by an anoxic mixed microbial culture, are removed from a polluted water stream through an anion-exchange membrane. The opposite side of this membrane is used for the development of a biofilm, contacting a biocompartment, to which nutrients and chloride are fed as a source of “driving” counter-ion. The applicability of a plate-and-frame IEMB module configuration, consisting of a series of membranes, for the treatment of drinking water contaminated with nitrate and perchlorate, was evaluated. Permeation of carbon source across the membrane to the treated water stream was avoided by a dedicated start-up procedure involving a gradual increase of ethanol feeding to the IEMB biocompartment. It was demonstrated that the biocompartment pH must be controlled not only to guarantee a complete perchlorate removal, but also to avoid precipitation of struvite on the membrane surface, which provokes membrane scaling and decreases the availability of nutrients for the biofilm. Under these conditions, the IEMB was successfully operated maintaining both nitrate and perchlorate concentrations in the treated water below their recommended levels for drinking water supplies.     

Accelerating effect of hydroxylamine and hydrazine on nitrogen removal rate in moving bed biofilm reactor

In biological nitrogen removal, application of the autotrophic anammox process is gaining ground worldwide. Although this field has been widely researched in last years, some aspects as the accelerating effect of putative intermediates (mainly N?H? and NH?OH) need more specific investigation. In the current study, experiments in a moving bed biofilm reactor (MBBR) and batch tests were performed to evaluate the optimum concentrations of anammox process intermediates that accelerate the autotrophic nitrogen removal and mitigate a decrease in the anammox bacteria activity using anammox (anaerobic ammonium oxidation) biomass enriched on ring-shaped biofilm carriers. Anammox biomass was previously grown on blank biofilm carriers for 450 days at moderate temperature 26.0 (±0.5) °C by using sludge reject water as seeding material. FISH analysis revealed that anammox microorganisms were located in clusters in the biofilm. With addition of 1.27 and 1.31 mg N L?1 of each NH?OH and N?H?, respectively, into the MBBR total nitrogen (TN) removal efficiency was rapidly restored after inhibitions by NO??. Various combinations of N?H?, NH?OH, NH??, and NO?? were used as batch substrates. The highest total nitrogen (TN) removal rate with the optimum N?H? concentration (4.38 mg N L?1) present in these batches was 5.43 mg N g?1 TSS h?1, whereas equimolar concentrations of N?H? and NH?OH added together showed lower TN removal rates. Intermediates could be applied in practice to contribute to the recovery of inhibition-damaged wastewater treatment facilities using anammox technology.     

Membrane bioreactor with a porous hydrophobic membrane as a gas-liquid contactor for waste gas treatment

A novel type of bioreactor for waste gas treatment has been designed. The reactor contains a microporous hydrophobic membrane to create a large interface between the waste gas and the aqueous phase. To test the new reactor, propene was chosen because of its high air/water partition coefficient, which causes a low water concentration and hampers its removal from air. Propene transfer from air to a suspension of propene-utilizing Xanthobacter Py2 cells in the membrane bioreactor proved to be controlled by mass transfer in the liquid phase. The resistance of the membrane was negligible. Simulated propene transfer rates agreed well with the experimental data. A stable biofilm of Xanthobacter Py2 developed on the membrane during prolonged operation. The propene flux into the biofilm was 1 x 10(-6) mol m(-2) s(-1) at a propene concentration of 9.3 x 10(-2) mol m(-3) in the gas phase. (c) 1995 John Wiley & Sons, Inc.     

Effects of biofilm formation on membrane performance in submerged membrane bioreactors

The effects of biofilm formation on membrane performance were evaluated for a submerged membrane bioreactor (sMBR) system with six different types of micro- and ultrafiltration membranes (working volume = 19 l). After operation for 24 h the permeability of the membranes with a larger pore size (microfiltration) decreased to that of the membranes with a much smaller pore size (ultrafiltration). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) confirmed that biofilms could reduce the influence of the membrane surface properties. The chemical oxygen demand (COD) removal efficiency was 95% for the oily wastewater treatment in the sMBR where the filtration process made an important contribution (47% based on feed COD). Significant enhancement in COD removal occurred at the initial filtration stage because of biofilm formation and the dynamic member role of the biofilm layer. Membranes with various pore sizes had approximately the same permeate quality that was attributed to the biofilm on the membrane surfaces. Nevertheless, the ultrafiltration membranes had 43% more COD removal efficiency than the other applied membranes at the beginning of filtration (before biofilm formation) because of the smaller pore sizes and better sieving.     

Performance of a membrane biofilm reactor for denitrification with methane

In this study, a membrane biofilm reactor was investigated for aerobic methane oxidation coupled indirectly to denitrification, a process potentially useful for denitrification of nitrate-contaminated waters and wastewaters using methane as external electron donor. Methane and oxygen were supplied from the interior of a silicone tube to a biofilm growing on its surface. We found that the membrane biofilm reactor was to some extent self-regulating in the supply of methane and oxygen. Although the intramembrane partial pressures of methane and oxygen were varied, the oxygen-to-methane ratio penetrating the membrane tended towards 1.68. Both nitrate removal rate and dissolved organic carbon (DOC) production rate appeared to be positively correlated with intramembrane methane pressure. Based on measured nitrate removal rates, DOC production rates, and nitrate removal efficiency, the possibility of using this method for treatment of a hypothetical wastewater was evaluated.