Enhancing Signal Output and Avoiding BOD/Toxicity Combined Shock Interference by Operating a Microbial Fuel Cell Sensor with an Optimized Background Concentration of Organic Matter

Abstract

In the monitoring of pollutants in an aquatic environment, it is important to preserve water quality safety. Among the available analysis methods, the microbial fuel cell (MFC) sensor has recently been used as a sustainable and on-line electrochemical microbial biosensor for biochemical oxygen demand (BOD) and toxicity, respectively. However, the effect of the background organic matter concentration on toxicity monitoring when using an MFC sensor is not clear and there is no effective strategy available to avoid the signal interference by the combined shock of BOD and toxicity. Thus, the signal interference by the combined shock of BOD and toxicity was systematically studied in this experiment. The background organic matter concentration was optimized in this study and it should be fixed at a high level of oversaturation for maximizing the signal output when the current change (ΔI) is selected to correlate with the concentration of a toxic agent. When the inhibition ratio (IR) is selected, on the other hand, it should be fixed as low as possible near the detection limit for maximizing the signal output. At least two MFC sensors operated with high and low organic matter concentrations and a response chart generated from pre-experiment data were both required to make qualitative distinctions of the four types of combined shock caused by a sudden change in BOD and toxicity.

Microbial fuel cell is emerging as a versatile technology: a review on its possible applications, challenges and strategies to improve the performances

“…The study revealed that the background organic matter concentration should be fixed at a high level of oversaturation for maximizing the signal output when the ‘ ∆I ’ is selected relative to the concentration of a toxic agent. On the other hand, IR should be fixed to a lower value near to the detection limit to maximize the signal output . The results of this study are shown in Figure .…”

“…Recently, Yong et al . studied the effect of organic matter concentration (in anode) on toxicity monitoring to avoid the signal interference by the combined shock of BOD and toxicity . The study revealed that the background organic matter concentration should be fixed at a high level of oversaturation for maximizing the signal output when the ‘ ∆I ’ is selected relative to the concentration of a toxic agent.…”

“…The signal interference of a microbial fuel cell (MFC) sensor by the combined shock of biochemical oxygen demand and toxicity in a continuous flow‐through mode: (a) the MFC sensor operated with background acetate of 0.3 mM; (b) the MFC sensor operated with background acetate of 5 mM . NaAc, sodium acetate.…”

Detection of 4-Nitrophenol, a Model Toxic Compound, Using Multi-Stage Microbial Fuel Cells

“…It is apparent therefore that MFCs respond to many toxic substances, but the magnitude of the response depends on the concentration and inherent toxicity of any particular compound. Importantly, using the MFC-based toxicity sensors reported to date there, are difficulties in distinguishing a drop in sensor output caused by a drop in BOD levels from a drop in sensor output caused by the presence of a toxic compound (Kim et al, 2006b;Jiang et al, 2016;Tan et al, 2018). There is therefore a clear need for the development of a sensor capable of distinguishing between BOD and toxicity detection.…”

A cathode-shared microbial fuel cell sensor array for water alert system

“…Among these, the microbial fuel cell (MFC) based sensor has attracted growing interest because it can achieve self-sustainable and low-cost water monitoring without additional transducers, power sources or specialty chemicals [2][3][4][5]. The bioanode of an MFC is generally used as the sensing and transducing element, at which electrogenic microorganisms oxidize the organic substrate and release protons and electrons [6][7][8][9].…”