Potential of the Electronic Nose as a Tool for the Detection of Disturbances in Anaerobic Digestion Processes

Most of agricultural biogas plants do not operate at optimum loading rate to avoid overload and process failure. This study aims at the development of an electronic nose technology to serve as a specific monitoring tool for anaerobic digestion processes. Twelve semi-continuous anaerobic mini-digesters (1.6 L useful capacity) were fed with three different substrates: sucrose, maize oil and a mix 1:1 of sucrose and maize oil. Two feeding strategies were followed (i) a cautious organic load (1.3 gVS.L-1.day-1) and (ii) an increasing load strategy (1.3 to 5.33 gVS.L-1.day-1). Digesters were monitored during two months by analysing the biogas composition and collecting electronic nose measurements. The electronic nose was able to detect the impact of organic load variations. Overload situations were distinguished by the e-nose apparatus and the different feeding substrates induced distinct responses from the e-nose system.