Abstract During last decades several techniques were proposed for the measurement of odours in environmental field but until now no one was applied and diffused between worldwide countries. These due to the presence of a large number of variables correlated to fast and continuous variability of odours, their low concentration in environment, the meteorological conditions, the difficulty to sampling a representative volume of air.

In Europe the dynamic olfactometry method was standardized in 2003 by EN 13725 and was proposed for the measurement of odour emissions. At same time several Countries have specific guidelines that norm in different way the assessment of odours.

The scope of this study is to compare and evaluate the principal odour measurement methods (GC-MS, dynamic olfactometry, and electronic nose), nowadays applied in technical practices and reported in current scientific literature, used to identify and characterize the odour emissions from a wastewater treatment plant, with the aim of analysing the weaknesses and strengths of the different techniques. The study of the correlation between odour concentrations measured by different methods was also presented. The evaluation and analyses of the different odour measurement techniques have been carried out at the ISWA Institute of the Department of Civil Engineering, Stuttgart University. The investigated samples, collected at the different odour sources at wastewater treatment plant (WWTP) LFKW located at Stuttgart University Campus (Northern Germany), are analysed by dynamic olfactometry, electronic nose (eNose) and gas chromatography and mass spectrometry (GC-MS).

The results obtained highlight the various data on the odour concentrations between different measurement methods at each sampling source of WWTP. Odour indexes were proposed to compare and evaluate the different sensorial and analytical techniques.