On Line Monitoring of Odour Nuisance at a Sanitary Landfill for Non-Hazardous Waste

A field study was carried out to assess the possibility of monitoring online malodours from a sanitary landfill for non-hazardous waste. To that aim, the performance of a multisensory electronic nose and a H2S continuous analyser used in situ was evaluated to identify odorous compounds in ambient air emitted from the landfill as perceived at the nearest municipal receptor (the city of Statte, Southern Italy) and compared with the results obtained in laboratory by dynamic olfactometry. Alert situations were conventionally established when two consecutive H2S concentration measurements at 5 min intervals exceeded 20 ppb or when odour emissions measured by the e-nose exceeded 500 OU/m3 for more than 5 min. The study comprised two main activities: 1) training the e-nose to recognize the odorous compounds emitted from the landfill; 2) evaluating the efficiency of the H2S continuous analyser to provide useful information related to biogas emission. Activity 1 demonstrated the e-nose effectiveness for on-line monitoring, quantifying and identifying the odours produced by the landfill. Data processing showed that CDA was the most suitable algorithm to achieve best odours’ pattern recognition. Activity 2 showed that H2S measurements, depending on site-specific factors identified by Kolmogorov-Smirnov test, were poorly correlated with odour concentration in ambient air measured by dynamic olfactometry, as dynamic olfactometry takes into account the effect of other emitted compounds or the masking/enhancing effect of other compounds over H2S. Accordingly, further site-specific investigation is deemed necessary in order to achieve full on-line control of air quality and to adopt proper management measures at sanitary landfills and other odour emitting sources.