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.

生物电化学传感器被证明是一种简单且低成本的方法，具有很高的潜力，可在厌氧消化（AD）过程中在线监测挥发性脂肪酸（VFA）。在此，开发了一种创新的双室空气阴极微生物燃料电池，作为用于VFA监测的生物传感器。生物传感器的响应是非线性的，并且随着VFA混合物浓度的增加（2.8–112 mM）而增加。同时，该关系在2-5小时内与低VFA水平（<14 mM）呈线性关系。高浓度的碳酸氢盐降低了电压。搅拌加快了响应速度并放大了信号，但降低了饱和浓度（约30 mM），因此缩小了检测范围。在启动期间，利用AD反应器的流出物进一步验证了生物传感器的适用性。由生物传感器测量的VFA浓度与气相色谱测量值具有很好的相关性。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，生物膜中的优势微生物被鉴定为地杆菌，Hydrogenophaga，Pelobacter，金黄，Oryzomicrobium和Dysgonomonas。