Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark.
Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark.
Water Res. 2017 Mar 15;111:74-80. doi: 10.1016/j.watres.2016.12.045. Epub 2016 Dec 29.
This study presents an innovative biosensor that was developed on the basis of a microbial electrolysis cell for fast and reliable measurement of volatile fatty acids (VFA) during anaerobic digestion (AD) process. The bio-electrolytic sensor was first tested with synthetic wastewater containing varying concentrations of VFA. A linear correlation (R = 0.99) between current densities (0.03 ± 0.01 to 2.43 ± 0.12 A/m) and VFA concentrations (5-100 mM) was found. The sensor performance was then investigated under different affecting parameters such as the external voltage, VFA composition ratio, and ionic strength. Linear relationship between the current density and VFA concentrations was always observed. Furthermore, the bio-electrolytic sensor proved ability to handle interruptions such as the presence of complex organic matter, anode exposure to oxygen and low pH. Finally, the sensor was applied to monitor VFA concentrations in a lab-scale AD reactor for a month. The VFA measurements from the sensor correlated well with those from GC analysis which proved the accuracy of the system. Since hydrogen was produced in the cathode as byproduct during monitoring, the system could be energy self-sufficient. Considering the high accuracy, short response time, long-term stability and additional benefit of H production, this bio-electrolytic sensor could be a simple and cost-effective method for VFA monitoring during AD and other anaerobic processes.
本研究提出了一种基于微生物电解池的创新生物传感器，用于快速可靠地测量厌氧消化（AD）过程中的挥发性脂肪酸（VFA）。该生物电解传感器首先用含有不同浓度 VFA 的合成废水进行测试。发现电流密度（0.03 ± 0.01 至 2.43 ± 0.12 A/m）与 VFA 浓度（5-100 mM）之间存在线性相关（R = 0.99）。然后研究了不同影响参数下（如外部电压、VFA 组成比和离子强度）传感器的性能。始终观察到电流密度与 VFA 浓度之间的线性关系。此外，生物电解传感器证明能够处理复杂有机物的存在、阳极暴露于氧气和低 pH 值等中断情况。最后，该传感器应用于监测实验室规模 AD 反应器中一个月的 VFA 浓度。传感器的 VFA 测量值与 GC 分析结果相关性良好，证明了该系统的准确性。由于在监测过程中阴极作为副产物产生了氢气，因此该系统可以实现能源自给自足。考虑到高准确性、短响应时间、长期稳定性以及 H 生产的额外好处，这种生物电解传感器可以成为 AD 和其他厌氧过程中 VFA 监测的一种简单且具有成本效益的方法。
