Integration of different electronic nose technologies in recognition of odor sources in a solid waste composting plant

Due to the continuous expansion of urban areas, the problem of emissions in the atmosphere of odors from solid industrial waste composting plants, are often cause of dissatisfaction and complaints by the communities surrounding emission sources. Characterization of emission sources by electronic noses is becoming a valuable approach in the management of odor emission, as are required high time resolution instrumental approaches and fast intervention on identified critical wastes, by using abatement systems. In this paper the authors compare complementary technologies: MOSs and polymer/black carbon (Nano Composite Array – NCA) based sensors electronic noses to monitor odors emitted from an industrial solid waste composting plant, in the aim to implement integrated policies for a better management of composting operations. 10 MOS sensors in the PEN3 (Airsense), operating at high temperature and 32 polymer/black carbon (Nano Composite Array – NCA) based sensors in the Cyranose 320 (Sensigent), operating almost at ambient temperature, were tested on samples collected above three odour sources in the composting plant: biogas, sludge and urban waste. The integrated dataset obtained from measures were explored by Principal Component Analysis and Discriminant Analysis to identify sensor discrimination capabilities, strengths and weaknesses of the technologies used. The results obtained highlight the advantages of monitoring the composting process with a multi-tech sensor approach, in order to provide complementary information useful to better discriminate the emissions from a waste composting plant.