Microbial fuel cells for inexpensive continuous in-situ monitoring of groundwater quality.
Microbial fuel cells for inexpensive continuous in-situ monitoring of groundwater quality.
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DOI：
10.1016/j.watres.2017.03.040
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发表时间：
2017-06
期刊：
影响因子：
12.8
通讯作者：
S. Velasquez-Orta;D. Werner;J. Varia;S. Mgana
中科院分区：
文献类型：
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作者：
S. Velasquez-Orta;D. Werner;J. Varia;S. Mgana
在线监测浅威尔斯井中的地下水质量，以检测粪便或有机污染，可以大大提高对无规划的城市周边住区健康风险的认识。微生物燃料电池（MFC）是一种能够从粪便污染中的有机物产生电能的装置，使其适合作为生物传感器。在这项工作中，我们评估了四个微生物燃料电池系统放置在不同地区的地下水井的粪便污染事件的低成本监测的适用性。所产生的概念包括使用沉积物/大量液体MFC（SED/BL）、沉积物/沉积物MFC（SED/SED）、大量液体/空气MFC（BL/空气）和大量液体/大量液体MFC（BL/BL）。MFC电极组件旨在使用廉价、耐用的材料，其将在污染事件后产生信号而无需外部能量或化学输入。所有MFC配置都对污染事件做出响应，但是SED/SED和BL/Air MFC概念在测试时间段内未能提供可再现的输出。污染后，BL/BL MFC和SED/BL MFC的平均电流分别从−0.75 ± 0.35 μA增加到−0.66 ± 0.41 μA，从0.07 ± 0.2 mA增加到0.11 ± 0.03 mA。SED/BL MFC（SMFC）产生的电流比BL/BL MFC高得多，使其响应更快，可读性更强，图形更清晰。一个析因实验设计（DOE），以评估环境和设计因素有最大的影响，在污染事件的电流响应。在测试的变量范围内，盐度，温度和外部电阻，只有温度呈现统计学显著性影响（p = 0.045）。这表明，生物传感器的响应将对温度的波动敏感，但对盐度的变化不敏感，也不对地下水井内不同距离处放置电极所产生的外部电阻敏感。
Online monitoring of groundwater quality in shallow wells to detect faecal or organic pollution could dramatically improve understanding of health risks in unplanned peri-urban settlements. Microbial fuel cells (MFC) are devices able to generate electricity from the organic matter content in faecal pollution making them suitable as biosensors. In this work, we evaluate the suitability of four microbial fuel cell systems placed in different regions of a groundwater well for the low-cost monitoring of a faecal pollution event. Concepts created include the use of a sediment/bulk liquid MFC (SED/BL), a sediment/sediment MFC (SED/SED), a bulk liquid/air MFC (BL/Air), and a bulk liquid/bulk liquid MFC (BL/BL). MFC electrodes assembly aimed to use inexpensive, durable, materials, which would produce a signal after a contamination event without external energy or chemical inputs. All MFC configurations were responsive to a contamination event, however SED/SED and BL/Air MFC concepts failed to deliver a reproducible output within the tested period of time. BL/BL MFC and SED/BL MFCs presented an increase in the average current after contamination from −0.75 ± 0.35 μA to −0.66 ± 0.41 μA, and 0.07 ± 0.2 mA to 0.11 ± 0.03 mA, respectively. Currents produced by the SED/BL MFC (SMFC) were considerably higher than for the BL/BL MFCs, making them more responsive, readable and graphically visible. A factorial design of experiments (DOE) was applied to evaluate which environmental and design factors had the greatest effect on current response in a contamination event. Within the ranges of variables tested, salinity, temperature and external resistance, only temperature presented a statistically significant effect (p = 0.045). This showed that the biosensor response would be sensitive to fluctuations in temperature but not to changes in salinity, or external resistances produced from placing electrodes at different distances within a groundwater well.