Nitrogen is used in agriculture to fertilise croplands. During the spreading of fertilisers, a substantial part of Nitrogen is lost by volatilisation of ammonia (NH3). These emissions are responsible for unpleasant odours but are also mainly precursors of particulate matters (PM). In Europe, agriculture is one of the main source of nitrogen-composed PM. There is a need to collect more emissions data to understand better this activity impact.

   Measurement techniques of NH3, used for ambient air quality monitoring, are expensive and heavy to manage for the agricultural sector. Other techniques less expensive, like passive sampling, are also used to estimate ammonia flow, but these devices are not adapted for continuous monitoring. For this reason, we decided to customise a common e-nose device to detect ammonia emissions from fertilised grasslands. The sensor array was built using six commercial metal oxide semiconductor sensors. The sensors were inserted radially and evenly into a small size cylindrical PTFE chamber. Four of the selected sensors were sensitive to ammonia, one was sensitive to VOC and the last one was for combustible gas.

   Wastewater treatment plants (WWTPs) produce gaseous emissions that might be olfactory annoying to the surrounding population. Current odour assessment methodologies are based on costly and infrequent olfactometry measurements involving human panels, and continuous monitoring of few gases via fixed gas detectors installed on the plant.

   This leads to odour measurements with low temporal and spatial resolution, hindering an accurate characterization of the odour episodes. The main goal of the SNIFFDRONE project, presented in this paper, is to develop a drone with olfaction capabilities to acquire spatially-dense odour measurements and localize the source of odour nuisances in WWTPs.