A novel open-type biosensor for the in-situ monitoring of biochemical oxygen demand in an aerobic environment

作者：Yamashita Takahiro; Ookawa Natsuki; Ishida Mitsuyoshi; Kanamori Hiroyuki; Sasaki Harumi; Katayose Yuichi; Yokoyama Hiroshi

来源：Scientific Reports, 2016, 6(1): 38552.

DOI：10.1038/srep38552

<jats:title>Abstract</jats:title><jats:p>Biochemical oxygen demand (BOD) is a widely used index of water-quality assessment. Since bioelectrochemical BOD biosensors require anaerobic conditions for anodic reactions, they are not directly used in aerobic environments such as aeration tanks. Normally, the BOD biosensors are closed-type, where the anode is packed inside a closed chamber to avoid exposure to oxygen. In this study, a novel bioelectrochemical open-type biosensor was designed for <jats:italic>in-situ</jats:italic> monitoring of BOD during intermittent aeration. The open-type anode, without any protection against exposure to oxygen, was directly inserted into an intermittently aerated tank filled with livestock wastewater. Anodic potential was controlled using a potentiostat. Interestingly, this novel biosensor generated similar levels of current under both aerating and non-aerating conditions, and showed a logarithmic correlation (R<jats:sup>2</jats:sup> &gt; 0.9) of current with BOD concentrations up to 250 mg/L. Suspended solids in the wastewater attached to and covered the whole anode, presumably leading to the production of anaerobic conditions inside the covered anode via biological oxygen removal. Exoelectrogenic anaerobes (<jats:italic>Geobacter</jats:italic> spp.) were detected inside the covered anode using the 16S-rRNA gene. This biosensor will have various practical applications, such as the automatic control of aeration intensity and the <jats:italic>in-situ</jats:italic> monitoring of natural water environments.</jats:p>

• 出版日期2016-12-5