Ishizaki So, Papry Rimana Islam, Miyake Hiroshi, Narita Yuko, Okabe Satoshi
Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan.
Front Microbiol. 2019 Jan 14;9:3284. doi: 10.3389/fmicb.2018.03284. eCollection 2018.
Integrated microbial fuel cell (MFC) and membrane bioreactor (MBR) systems are a promising cost-effective and energy-saving technology for wastewater treatment. Membrane fouling is still an important issue of such integrated systems in which aeration (oxygen) is replaced with anode electrodes (anodic respiration). Here, we investigated the effect of culture conditions on the membrane fouling potential of fouling-causing bacteria (FCB). In the present study, strain S05, which is an exoelectrogenic FCB isolated from a MBR treating municipal wastewater, was cultured with different external electron acceptors (oxygen, nitrate, and solid-state anode electrode). As results, the fouling potential of S05 was lowest when cultured with anode electrode and highest without any external electron acceptor ( < 0.05, respectively). The composition of soluble microbial products (SMP) and extracellular polymeric substances (EPS) was also dependent on the type of electron acceptor. Protein and biopolymer contents in SMP were highly correlated with the fouling potential ( = 0.73 and 0.81, respectively). Both the fouling potential and yield of protein and biopolymer production were significantly mitigated by supplying electron acceptors sufficiently regardless of its types. Taken together, the aeration of MBR could be replaced with solid-state anode electrodes without enhancement of membrane fouling, and the anode electrodes must be placed sufficiently to prevent the dead spaces in the integrated reactor.
集成微生物燃料电池（MFC）和膜生物反应器（MBR）系统是一种很有前景的具有成本效益和节能的废水处理技术。膜污染仍然是这种集成系统的一个重要问题，在该系统中，曝气（氧气）被阳极电极（阳极呼吸）所取代。在此，我们研究了培养条件对致污细菌（FCB）膜污染潜力的影响。在本研究中，从处理城市废水的MBR中分离出的产电FCB菌株S05，用不同的外部电子受体（氧气、硝酸盐和固态阳极电极）进行培养。结果表明，S05在与阳极电极一起培养时的污染潜力最低，而在没有任何外部电子受体的情况下最高（分别为<0.05）。可溶性微生物产物（SMP）和细胞外聚合物（EPS）的组成也取决于电子受体的类型。SMP中的蛋白质和生物聚合物含量与污染潜力高度相关（分别为=0.73和0.81）。无论电子受体类型如何，通过充分供应电子受体，蛋白质和生物聚合物产生的污染潜力和产量均显著降低。综上所述，MBR的曝气可以用固态阳极电极替代而不会加剧膜污染，并且阳极电极必须放置得当以防止集成反应器中出现死区。
