Department of Environmental Engineering, Technical University of Denmark, DK-2800, Lyngby, Denmark; College of Engineering, China Agricultural University, Beijing, 100083, PR China.
Department of Environmental Engineering, Technical University of Denmark, DK-2800, Lyngby, Denmark.
Chemosphere. 2021 Jun;273:129660. doi: 10.1016/j.chemosphere.2021.129660. Epub 2021 Jan 16.
Bioelectrochemical sensors have proven attractive as simple and low-cost methods with high potential for online monitoring of volatile fatty acids (VFA) in the anaerobic digestion (AD) process. Herein, an innovative dual-chamber air-cathode microbial fuel cell was developed as biosensor for VFA monitoring. The response of the biosensor was nonlinear and increased along with the concentration of VFA mixture increase (2.8-112 mM). Meanwhile, the relationship was linear with low VFA levels (<14 mM) within 2-5 h reaction. High concentrations of bicarbonate decreased the voltage. Stirring speeded up the response and amplified the signal but reduced the saturation concentration (approximately 30 mM) and therefore narrowed the detection range. The applicability of the biosensor was further validated with the effluents from an AD reactor during a start-up period. The VFA concentrations measured by the biosensor were well correlated with the gas chromatographic measurement. The results demonstrate that this biosensor with a novel design could be used for VFA monitoring during the AD process. Based on the 16S rRNA gene sequencing, the dominant microbiomes in the biofilm were identified as Geobacter, Hydrogenophaga, Pelobacter, Chryseobacterium, Oryzomicrobium, and Dysgonomonas.
生物电化学传感器已被证明是一种简单且低成本的方法，具有在厌氧消化（AD）过程中在线监测挥发性脂肪酸（VFA）的高潜力。在此，开发了一种创新的双室空气阴极微生物燃料电池作为 VFA 监测的生物传感器。该生物传感器的响应是非线性的，并随着 VFA 混合物浓度的增加（2.8-112 mM）而增加。同时，在 2-5 h 的反应时间内，低 VFA 水平（<14 mM）的关系呈线性。高浓度的碳酸氢盐会降低电压。搅拌会加快响应并放大信号，但会降低饱和浓度（约 30 mM），从而缩小检测范围。该生物传感器在 AD 反应器启动期间的流出物中的适用性进一步得到了验证。生物传感器测量的 VFA 浓度与气相色谱测量值具有良好的相关性。结果表明，这种具有新颖设计的生物传感器可用于 AD 过程中的 VFA 监测。基于 16S rRNA 基因测序，确定生物膜中的优势微生物组为 Geobacter、Hydrogenophaga、Pelobacter、Chryseobacterium、Oryzomicrobium 和 Dysgonomonas。
