Interest in the Use of an Electronic Nose for Field Monitoring of Odors in the Environment

Abstract

An electronic nose is a promising technique for field monitoring of malodors in the environment. It is based on an array of nonspecific gas sensors coupled with some form of mathematical data processing method to analyze global response patterns. Some applications concerning the control of water quality are reported in the literature. They often imply the generation of a headspace gas above liquid samples, but they also concern the odor emitted in the air from wastewater. The typical needs of the final user require both qualitative and quantitative approaches, that is, both discriminating between slight variations in complex gas mixtures and monitoring a global odor signal that can be correlated with classical characterization variables of water or air quality. Although potential applications in odor 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, and developing calibration procedures to account for sensor drift. The present limitations of electronic nose technology restrict its use in the environment to odor monitoring in the surroundings of the emission by instruments specifically designed for the application.