Focusing on the process diagnosis of anaerobic fermentation by a novel sensor system combining microbial fuel cell, gas flow meter and pH meter

Process diagnosis is essential to ensure anaerobic fermentation stable and efficient. Here, a novel sensor system combining microbial fuel cell (MFC), gas flow meter and pH meter was developed to evaluate its feasibility for probing the anaerobic process established on a model high-rate bioreactor. Repeated transient responses of electrical signal, proton concentration, and gas flow rate, were observed subject to external disturbances. The transient response lasted from <1 h to 6 h. In addition, MFC obtained compatible signal variations with other sensors, and biofilm MFC (MFCBiofilm) resulted in better agreements than control MFC (MFCControl). These results revealed that 1) the composite sensor system was capable to probe anaerobic process, suggesting a novel approach for process analysis and diagnosis of biogas or biohydrogen production; 2) the variations of sensor signals might provide more valuable information for process diagnosis than sensor signals themselves.