A novel bioelectrochemical BOD sensor operating with voltage input

Abstract

Biochemical oxygen demand (BOD) is a measure of biodegradable compounds in water and is, for example, a common parameter to design and assess the performance of wastewater treatment plants. The conventional method to measure BOD is time consuming (5 or 7 days) and requires trained personnel. Bioelectrochemical BOD sensors designed as microbial fuel cells (MFCs), which are systems where bacteria convert organic matter into an electrical current, have emerged as an alternative to the conventional technique. In this study, a new type of bioelectrochemical BOD sensor with features that overcome some of the limitations of current MFC-type designs was developed: (1) An external voltage was applied to overcome internal resistances and allow bacteria to generate current at their full capacity, and (2) the ion exchange membrane was omitted to avoid pH shifts that would otherwise limit the applicability of the sensor for wastewaters with low alkalinity. The sensor was calibrated with an aerated nutrient medium containing acetate as the BOD source. Linear correlation (R(2) = 0.97) with charge was obtained for BOD concentrations ranging from 32 to 1280 mg/L in a reaction time of 20 h. Lowering the reaction time to 5 h resulted in lowering the measurable BOD concentration range to 320 mg/L (R(2) = 0.99). Propionate, glucose, and ethanol could also be analyzed by the sensor that was acclimated to acetate. The study demonstrates a way to design more robust and simple bioelectrochemical BOD sensors that do not suffer from the usual limitations of MFCs (high internal resistance and pH shifts).

Novel Applications of Microbial Fuel Cells in Sensors and Biosensors

“…The high sensitivity of the MFC's performance to a number of environmental and biological factors make them suitable to act, in turn, as biosensors [21,107,108]. Therefore, properly combining energy generation and sensing functionalities from MFCs, self-powered devices, i.e., operated without any external electricity supply, can be designed to operate autonomously for remote detection and quantification of desired parameters [109,110].…”

Detection of low concentration of assimilable organic carbon in seawater prior to reverse osmosis membrane using microbial electrolysis cell biosensor

“…The lowest detection limit of the described biosensor was 10 μM acetate. In comparison to other microbial organic substrate determination methods, the method in this study is more sensitive, quicker (range from 5 to 20 h [15]), and does not require pure culture (e.g. bioluminescence-based test that required Pseudomonas fluorescens P17 of Spirillum sp.…”

“…Previous studies showed that a MFC acclimated to high AP produced higher current (30% more) than a MFC acclimated to a lower AP [15]. For maximum power production, the AP should be as low and the cathode potential as high as possible of a MFC [13].…”

Microbial fuel cells for biosensor applications

“…This means apart from serving as an alternate power source for remote sensors, MFCs themselves may be used as sensors to detect many parameters Modin and Wilén 2012;Uríaa et al 2012). Though some reviews (Dewan et al 2014;Sun et al 2015) briefly mention MFC sensors with limited applications, this present review summarizes the latest developments in various biosensor applications using MFCs including monitoring microbial activity, testing BOD, detection of toxicants, detection of microbial biofilms that cause biocorrosion and some other unusual application.…”