Interest of the use of electronic nose for field monitoring of odours in the environment

Electronic nose is a promising technique for field monitoring of malodours in the environment. It is based on an array of non-specific gas sensors coupled with some form of mathematical data processing method to analyse the global response patterns. Some applications concerning the control of water quality are reported in the literature. They often impliy the generation of a headspace gas above liquid samples, but they also concern the odour emitted in the air from wastewater.
The typical needs of the final user require both qualitative and quantitative approaches, i.e. both discriminating between slight variations in complex gas mixtures and monitoring a global odour signal which can be correlated with classical characterisation variables of water or air quality.
Although potential applications in odour assessment by electronic noses are numerous, a number of challenges still need to be overcome: understanding and controlling the impact of environmental parameters (such as temperature and humidity), improving sensor sensitivity and noise reduction or developing calibration procedures to account for sensor drift. The present limitations of electronic nose technology restrict its use in the environment to the odour monitoring in the surroundings of the emission with instruments specifically designed for the application.