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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

View Article: PubMed Central - PubMed

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.

No MeSH data available.


The use of the microbial fuel cell (MFC) sensor for organic matter detection: (A) the use of the MFC sensor for organic matter detection (0–5 mM) in a continuous flow-through mode; (B) the correlation of the output plateau current with the acetate concentration, which was used to select the typical background concentrations.
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ijms-17-01392-f001: The use of the microbial fuel cell (MFC) sensor for organic matter detection: (A) the use of the MFC sensor for organic matter detection (0–5 mM) in a continuous flow-through mode; (B) the correlation of the output plateau current with the acetate concentration, which was used to select the typical background concentrations.

Mentions: The MFC sensor was first used for organic matter detection in a continuous flow-through mode, as show in Figure 1A. The stepwise change in the acetate concentration (0–5 mM) in the anolyte led to the corresponding change in the current output. The correlation of the output plateau current with the acetate concentration was shown in Figure 1B. The lowest detection limit of the MFC sensor was 0.25 μM acetate, while the acetate concentrations (0.25–0.7 mM) and current output were highly correlated with R2 values >0.99. The response time significantly varied with a range from 20 min to 2 h depending on the acetate concentrations, which was in accordance with previous studies using an MFC which held a similar volume in the anode chamber [13,14]. Three acetate concentrations were selected for the following background organic matter optimizing test: 0.3 mM (near the detection limit), 0.5 mM (half-saturated maxing current), and 5 mM (oversaturation).


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
The use of the microbial fuel cell (MFC) sensor for organic matter detection: (A) the use of the MFC sensor for organic matter detection (0–5 mM) in a continuous flow-through mode; (B) the correlation of the output plateau current with the acetate concentration, which was used to select the typical background concentrations.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037672&req=5

ijms-17-01392-f001: The use of the microbial fuel cell (MFC) sensor for organic matter detection: (A) the use of the MFC sensor for organic matter detection (0–5 mM) in a continuous flow-through mode; (B) the correlation of the output plateau current with the acetate concentration, which was used to select the typical background concentrations.
Mentions: The MFC sensor was first used for organic matter detection in a continuous flow-through mode, as show in Figure 1A. The stepwise change in the acetate concentration (0–5 mM) in the anolyte led to the corresponding change in the current output. The correlation of the output plateau current with the acetate concentration was shown in Figure 1B. The lowest detection limit of the MFC sensor was 0.25 μM acetate, while the acetate concentrations (0.25–0.7 mM) and current output were highly correlated with R2 values >0.99. The response time significantly varied with a range from 20 min to 2 h depending on the acetate concentrations, which was in accordance with previous studies using an MFC which held a similar volume in the anode chamber [13,14]. Three acetate concentrations were selected for the following background organic matter optimizing test: 0.3 mM (near the detection limit), 0.5 mM (half-saturated maxing current), and 5 mM (oversaturation).

View Article: PubMed Central - PubMed

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.

No MeSH data available.