微生物燃料电池在污水生物脱氮中的研究进展

微生物燃料电池(MFC)是一种新型污水处理技术,其在处理污水的同时能产生电能,引起众多研究者的关注.将MFC应用于含氮污水的处理中便形成了反硝化或同步硝化反硝化MFC系统.本文回顾了MFC生物脱氮的发展历程,并从MFC实验装置的设计构造(空间构型、电极材料、分隔材料)、影响因素(含氮污染物浓度、水力停留时间、溶解氧、碳源与碳氮比、温度、pH值、外电阻)和反硝化细菌的基因表达与多样性等3个方面进行了综述与分析,提出需要从以下方面进行MFC生物脱氮效能的强化:开发具有强电子传输能力和氨氧化催化功能的廉价高效电极材料,优化MFC脱氮的运行条件和探索不同环境下的脱氮机理,通过研究MFC阴极微生物种群构成筛选培育优势反硝化功能菌.     

电极对微生物燃料电池同时处理有机废水和含铜重金属废水产电性能的影响

实验以有机废水为阳极底物,以活性污泥中的混合菌为阳极接种微生物,以含铜废水为阴极液,构建双室MFC,探讨电极对MFC同时处理有机废水和含铜重金属废水产电性能的影响.结果表明:MFC对阳极有机废水COD的去除率最高为79.1%,对阴极液中Cu²⁺的去除率最高为95.6%.活性炭/石墨棒电极MFC产电性能最优,开路电压最高为800mV,是石墨棒电极MFC的1.25倍,是活性炭/碳纸电极MFC的1.3倍,是碳纸电极MFC的1.5倍.当电极距离为2cm时,MFC开路电压580mV,内阻为181Ω,产电性能最优.电极表面积为75cm²时,MFC的开路电压470mV,是电极表面积为50cm²的MFC的1.1倍,是电极表面积为30cm²的MFC的2.1倍.当A_An/A_cat=0.4时MFC产能最佳,MFC的开路电压最高为600mV,最大功率密度48.2mW/m².     

Influence of NO3 and SO4 on power generation from microbial fuel cells

Potential competition in terms of electron transfer from bacteria to electron acceptors such as nitrate (NO₃) and sulfate (SO₄) or the anode of a microbial fuel cell (MFC) was investigated to determine how alternative electron acceptors would influence power generation in an MFC. The cell voltage was not initially affected when these electron acceptors were introduced into the MFCs. However, the presence of NO₃ decreased the CE of the MFC compared to the injections of SO₄ or control salt (sodium chloride). This suggests that the growth of nitrate-reducing bacteria independent of the microbial populations on the MFC anode were not utilizing the anode as an electron acceptor, rather, they were consuming organic carbon in the anodic chamber of the MFC, resulting in a decrease of the CE of this MFC with no immediate impact on power output. This suggests that the bacterial consortium in the nitrate-MFC still preferred the anode over nitrate as the electron acceptor, although the theoretical reduction voltage of nitrate (+0.74 V) is higher than the reduction voltage in an MFC air cathode (as high as +0.425). These results are useful when considering whether MFC technology can be applied in situ to enhance biodegradation of organic contaminants in the presence of alternative electron acceptors.     

MFC-MEC耦合系统产电性能及处理含镉重金属废水的研究

以厌氧活性污泥为阳极菌种,乙酸钠为阳极底物,硫酸铜和重铬酸钾溶液为微生物燃料电池（MFC）阴极液,人工模拟含镉重金属废水为微生物电解池（MEC）阴极液,构建MFC-MEC耦合系统,利用MFC的产电驱动MEC运行,在不消耗外部能源的情况下,实现含镉重金属废水中Cd²⁺的去除。实验研究了MFC反应器容积、MFC堆栈、MEC电极材料、MEC阴极液pH对MFC-MEC耦合系统电性能及含镉重金属废水处理效果的影响。结果表明：MFC反应容积的扩大可以提高其产电性能,但与此同时会造成MFC的内阻升高,随着MFC容积的增加,MEC中Cd²⁺去除率逐渐增加,但同时MFC阴极Cr⁶⁺去除率逐渐下降;MFC堆栈可以提高工作组两端电压,串联时最大输出电压为1509 mV,Cd²⁺去除率为69.3%;以钛板作为MEC电极时,微生物能有效附着在阳极表面,MFC阳极COD去除率为85%,MEC中Cd²⁺去除率为51.5%;MEC阴极液pH在3~5时,有利于含镉重金属废水的处理,Cd²⁺去除率80%以上。经XRD分析,MEC阴极还原产物为CdCO₃。     

Preliminary Study on E. coli Microbial Fuel Cell and On-electrode Taming of the Biocatalyst

A mediator microbial fuel cell (MFC) was constructed by using E. coli as biocatalyst and new methylene blue as electron mediator. E. coli cells were carried out in anaerobic growth prior to inoculating them into the MFC in order to pre-adapt bacterial metabolism in an anaerobic environment, the electricity generation of MFC was tested, its maximum power density reached 263.94 mW/m2 with the corresponding current density 1287.50 mA/m2, the internal resistance of MFC was 200 W, and capability of the MFC was even better than those reported so far. Moreover, on-electrode taming method was adopted to improve electrochemical activity of E. coli, namely a combination of E. coli taming and electricity generation simultaneously in the same MFC without scraping off the biofilm of MFC, after the 4th on-electrode taming, the tamed E. coli MFC showed a 54% improvement in peak current density, being 612.50 mA/m2, and a 64% improvement in the maximum power output, being 166.67 mW/m2, compared with that of parental E. coli MFC. And the maturation time of tamed biofilm was obviously reduced to 240 min, quickening up 1 times compared with that of parental E. coli biofilm.     

以加热预处理污泥上清液为底物的微生物燃料电池基础特性

以单室空气阴极微生物燃料电池(MFC)为反应器,考察了以加热预处理污泥上清液为底物的MFC产电情况. 结果表明,污泥90℃下加热3 h时MFC输出功率最高(44.4 mW/m2),是未加热的105倍. 在此预处理条件下,污泥上清液中所含有机物成分最有利于阳极微生物的代谢产电. 加热后的污泥再次加热作为MFC底物产电,输出功率只有5.8 mW/m2. 加热预处理可提高以污泥上清液为底物的MFC的输出功率,且易与现有工艺结合,更接近实际应用.     

Mechanical and barrier properties of cardboard and 3D packaging coated with microfibrillated cellulose

Microfibrillated cellulose (MFC) is increasingly used with cellulosic substrates and especially with paper materials. Its use with cardboard remains not reported and the study of mechanical and barrier properties of MFC‐coated cardboard has been investigated in this article. The influence of coating process as well as the effect of MFC have been highlighted by comparing different MFC‐coated cardboard samples with PE‐coated cardboard samples. MFC was coated using bar coating process. Their distribution and homogeneity onto cardboard was observed using techniques such as SEM and FE‐SEM. Tests such as oxygen and air permeability, bending stiffness, and compressive strength have been carried out. The coating process used impacts significantly cardboard properties by two opposite ways: on one hand it damages the structure cohesion of cardboard decreasing its compressive strength; on the other hand it increases its bending stiffness by increasing considerably the samples thickness. The addition of MFC counterbalances the negative effects of the coating process: bending stiffness and compressive strength are indeed improved by 30% in machine direction. On the contrary, MFC does not enhance much cardboard barrier properties, although it considerably increases their water absorption. Within a framework of packaging application, MFC will rather have consequent effects on cardboard's properties as blend or as part of the multilayer structure. Other applications have to be considered for its use as top layer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40106.     

Cellulose fibres, nanofibrils and microfibrils: The morphological sequence of MFC components from a plant physiology and fibre technology point of view

During the last decade, major efforts have been made to develop adequate and commercially viable processes for disintegrating cellulose fibres into their structural components. Homogenisation of cellulose fibres has been one of the principal applied procedures. Homogenisation has produced materials which may be inhomogeneous, containing fibres, fibres fragments, fibrillar fines and nanofibrils. The material has been denominated microfibrillated cellulose (MFC). In addition, terms relating to the nano-scale have been given to the MFC material. Several modern and high-tech nano-applications have been envisaged for MFC. However, is MFC a nano-structure? It is concluded that MFC materials may be composed of (1) nanofibrils, (2) fibrillar fines, (3) fibre fragments and (4) fibres. This implies that MFC is not necessarily synonymous with nanofibrils, microfibrils or any other cellulose nano-structure. However, properly produced MFC materials contain nano-structures as a main component, i.e. nanofibrils.     

厌氧污泥接种双室微生物燃料电池去除氨氮的研究

构建并成功运行了厌氧污泥接种的双室MFC系统,评估了该系统处理模拟氨氮废水的效果,阐明微生物生态同MFC耦合氨氮去除的内在联系。结果表明,接种厌氧污泥的MFC电压输出最高可达523 m V,优于接种普通活性污泥的同型MFC。该双室MFC阳极室对低浓度氨氮废水(53 mg/L)的去除率最高为52.5%,对高浓度氨氮废水(294 mg/L)的去除率最高可达91.4%。基于SEM和DGGE的表征证实,接种MFC运行前后的厌氧污泥生物膜形貌和微生物群落结构都有明显的变化,群落多样性减少,优势种群数量增加,部分为典型胞外电子呼吸菌地杆菌。     

Physical properties and morphology of films prepared from microfibrillated cellulose and microfibrillated cellulose in combination with amylopectin

Two types of microfibrillated cellulose (MFC) were prepared using either a sulfite pulp containing a high amount of hemicellulose (MFC 1) or a carboxymethylated dissolving pulp (MFC 2). MFC gels were then combined with amylopectin solutions to produce solvent‐cast MFC‐reinforced amylopectin films. Tensile testing revealed that MFC 2‐reinforced films exhibited a more ductile behavior and that MFC 1‐reinforced films had higher modulus of elasticity (E‐modulus) at MFC loadings of 50 wt % or higher. Pure MFC films had relatively low oxygen permeability values when data were compared with those for a variety of other polymer films. MFC 1 and MFC 2 films had similar opacity but differences in appearance which were attributed to the presence of some larger fibers and nanofiber agglomerates in MFC 2. Field emission scanning electron microscopy (FE‐SEM) and atomic force microscopy (AFM) were used to illustrate the morphology of MFC nanofibers in pure films and in an amylopectin matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

高压均质化处理对微纤化纤维素性质的影响

以竹浆为原料,结合前期的磨浆机(PFI磨)磨浆和化学氧化预处理,研究了高压均质化处理对制备微纤化纤维素(MFC)产品的纤维表面形态及保水值的影响,并确定了最优均质化处理工艺。结果表明,高压均质化处理对纤维具有明显的破壁作用,随着均质化处理次数的增加,纤维的比表面积逐渐增大;同时,通过均质化处理次数与MFC保水值之间的关系,建立起了两者之间的数学模型,从而可以通过控制均质化处理次数来得到具有不同保水值的MFC产品,为MFC的制备提供指导;另外,高压均质机的主腔孔径对MFC保水值也有较大影响,在其它处理条件相同的情况下,主腔孔径越小,所得MFC的保水值越大。     

微生物燃料电池处理高盐废水的研究进展

高盐废水通常采用生化、蒸发和膜处理3种方法处理,但无论采用何种方法,高盐废水处理均存在难度大和成本高等问题。微生物燃料电池（MFC）是一种基于产电微生物催化氧化有机物获得电能的装置,应用MFC处理废水可实现在处理废水的同时回收废水中能量,从而降低废水处理成本。近年来,应用MFC处理高盐废水来降低处理成本的研究逐渐开展并成为一个研究热点。本文综述了MFC处理高盐废水研究的最新进展,分析了盐度对MFC产电、污染物脱除、微生物生长和群落的影响,基于耐盐微生物、生物膜、反应器结构及扩展应用等方面提出未来MFC处理高盐废水的研究方向。     

Preparation and characterization of green-based anti-ultraviolet and antidripping biodegradable film

The biodegradable materials cannot meet the requirements as the agricultural film due to the poor UV resistance and antidripping performance. The work herein thus presented the development of the green-based anti-ultraviolet and antidripping multifunctional composite films using poly(butyleneadipate-co-terephthalate), microfibrillated cellulose (MFC), and soybean protein isolate (SPI) as the raw materials in the presence of other agents. The resulting composite films were systematically characterized using scanning electron microscope, thermogravimetry analysis (TG), UV, and rheometer measurements. The morphology changed obviously after introducing the MFC and SPI into the substrate film. In addition, the results indicated that the addition of MFC and SPI had a positive effect on the thermal stability and heat preservation of the film, respectively. The contact angle results indicated that SPI was an ideal antidripping agent and the MFC could be used as the release agent. The time of the first water drop of the film containing 2.5 g MFC and 2.0 g SPI was 6 min and 46 s, and the time of each 10 drops was less than 60 s, showing the advantages of using MFC as the release agent and SPI as the antidripping agent. The resulting multifunctional biodegradable films can be widely used in the agricultural and packaging fields.     

Additive effects of tripalmitin and low-density polyethylene on morphologies and tensile properties of polybutene-1/micro fibrous cellulose composite

Effects of tripalmitin (TP) and low-density polyethylene (LDPE) loading on morphologies and tensile properties of polybutene-1 (PB)/micro fibrous cellulose (MFC)/composite were studied. The scanning electron microscope (SEM) observation showed that the 10 % TP loading brought about good dispersity of the MFC in PB matrix. The TP worked as a good compatibilizer for the composite. The Young’s moduli of the PB/TP (10 %)/MFC (10 and 20 %) content were slightly lower than those of the corresponding PB/MFC under 0, 48 and 96 h aging treatments at r. t., and that of the PB/TP (10 %)/MFC (50 %) specifically decreased up to 73 %. The TP loading increased the PB crystal phase transformation rate, and its behavior suggested that there existed TP in the interface between the PB and MFC. The elongation at break values increased up to 281 % of the corresponding PB/MFC ones. The 30 % TP loading little improved the tensile properties of the composite as compared with the 10 % one. The 10 % LDPE loading brought about 5–51 % higher Young’s moduli than those of the corresponding PB/MFC without the aging treatment although the composite rapidly became embrittlement by the higher MFC content and aging. It was found that the LDPE loading highly improved the interface strength, in particular, without the aging treatment.     

PVA/OPD改性膜对微生物燃料电池性能的影响

为提高微生物燃料电池（MFC）的性能，以聚乙烯醇（PVA）为黏合剂，分别以磷钨酸（PWA）和邻苯二胺（OPD）为改性剂，采用溶液浸渍法制备了PVA/PWA和PVA/OPD改性膜并搭载于MFC系统，以SEM、电化学阻抗谱（EIS）、循环伏安法（CV）、吸水率表征了膜的性能，并考察膜改性对MFC产电量和化学需氧量（COD）去除率的影响。结果显示，PVA/PWA和PVA/OPD改性膜均能在一定程度上提升MFC性能，但PVA/OPD改性膜效果更佳。PVA/OPD改性膜的吸水率为14.49%，较常规Nafion 117膜（NF）提高了126.05%。采用PVA/OPD改性膜的MFC在测试周期内的产电量为101.75 J，较采用NF时提高了587.50%；对阿莫西林制药废水的COD去除率为66.2%，较采用NF时提高了48.4%。基于PVA/OPD的膜改性方法对提高MFC的产电性能和废水处理效果有显著作用。     

Syndiotactic polypropylene/microfibrous cellulose composites: Effect of filler size on tensile properties

Syndiotactic polypropylene (SPP)/ethanol swelled microfibrous cellulose (MFC) composite was prepared by a melting mixer, and its morphology and tensile properties were studied. The scanning electron microscope microphotograph did not show the aggregated MFC part up to the 40 wt % MFC loading content, and the Young's modulus was exponentially increasing with the increase of the MFC loading content. These results suggested that the MFC was well‐dispersed in the SPP matrix by an ethanol surfactant work. The Young's modulus was much higher than that of the composite with commonly used fibrous cellulose and moreover, exceeded the theoretical one obtained from the Halpin‐Tsai equation. The differential scanning calorimetry and wide‐angle X‐ray diffraction measurements showed that the MFC acted as a good α‐nucleation agent for SPP. It was found that the excessive Young's modulus of the MFC composite was originated from an increase of that of the SPP matrix induced by the α‐nucleation effect. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

微生物燃料电池的动态性能分析及其神经网络预测控制

微生物燃料电池（microbial fuel cell,MFC）反应底物浓度的控制问题是整个系统优化控制的重要环节,其控制效果的优劣对系统的输出电压有很大的影响。针对MFC输出电压在常规控制策略下超调量大和响应速度慢的特点,对MFC系统模型中输入量、控制量的变化对系统输出的影响进行动态仿真;将负载电流作为扰动量,提出了针对MFC系统阳极进料流量进行控制的神经网络预测控制策略。仿真结果表明,与PID控制方法相对比,利用神经网络预测控制策略的系统输出电压响应速度快且超调量小,其动态性能得到了较大的改善。     

微生物燃料电池技术及其影响因素研究进展

微生物燃料电池(Microbial fuel cell,MFC)作为一种绿色能源技术,通过微生物的氧化代谢作用将废水中的有机质降解的同时产生电能.然而,其相对较低的产电效率限制了MFC的工业化应用.该文介绍了影响MFC性能的诸多因素,如设备的构型限制、电极材料、阳极底物、阳极微生物和质子交换膜等,提出优化MFC的设计,提高MFC的产电性能,降低投入成本可解决MFC产业化应用的弊端,并对未来MFC的发展方向进行了展望.     

聚乙烯醇/微纤化纤维素复合微发泡材料的制备

通过溶液浇铸法制备了聚乙烯醇(PVOH)/微纤化纤维素(MFC)复合薄膜材料,以超临界二氧化碳(scCO₂)为物理发泡剂,采用间歇式降压法制备了一系列PVOH/MFC复合微发泡材料,主要讨论了在没有水分的影响下,不同发泡温度和时间以及MFC含量对PVOH/MFC复合微发泡材料的泡孔形貌、泡孔尺寸和泡孔密度的影响;同时,也对MFC的分散性和PVOH/MFC复合材料的流变性能和热性能对发泡行为的影响进行了研究。实验结果表明,均匀分散在PVOH基体中的MFC作为异相成核剂提高了气孔成核能力,且随着MFC含量的增加,泡孔尺寸降低,泡孔密度增大;并研究了发泡温度对PVOH/MFC复合材料的发泡形貌的影响,获得最优发泡温度。     

单室不锈钢阳极微生物燃料电池强化反硝化的研究

采用碳布阴极,不锈钢阳极构建了以葡萄糖为唯一电子供体、硝酸盐作为电子受体管状单室微生物燃料电池(MFC),研究MFC的COD、NO3-去除情况和强化反硝化性能。在室温下,初始COD为595 mg/L,外接电阻100、1000Ω时,该MFC去除率为62%、56%,比厌氧对照组高10%~15%,NO3-去除率为60%、58%,比厌氧对照组高10%。表明该MFC在能良好降低COD的同时,也能够很好的去除硝酸盐,并且强化了反硝化过程,是一种很高效的去除硝酸盐的方法。给我们在MFC的研究和硝酸盐的降解中提供了一个新的方向,对加深理解MFC机理,推动MFC技术发展和降解硝酸盐的水处理的应用具有理论与实际意义。