Closed reactors were set up in water baths in the laboratory to enable their operating temperature to be changed. In the experiment described in this paper the temperature was kept at 40ºC and the waste used was the vegetable fraction of food waste. Each reactor was fitted with an aeration system which could maintain aerobic conditions inside the reactors when needed.
Samples of the headspace gas were analysed and the odour was assessed during the biodegradiation process. Oxygen was measured in the headspace gas, and parameters such as the oxidation reduction potential (redox) were measured in the solid material.
The reactors were initially operated aerobically and then the air was turned off. The changes in headspace gases and redox were then monitored as the conditions became anaerobic and the results compared to those of the electronic nose. The initial results from the trials indicate that the electronic nose can detect an early transition from aerobic to anaerobic conditions, but at this stage more work is needed in the laboratory. Further trials are taking place in the field.