The odoriferous profile of WWTP emissions is typically associated with the presence of Volatile Sulphur Compounds (VSC), such as H2S, mercaptans and thioethers. There are different systems for continuous monitoring of odour in ambient air and / or emission (such as H2S detectors and electronic noses). These systems are typically based on low-cost sensors that do not allow the main odorants to be determined reliably at low enough levels such as those typically present in immission. As an alternative, it has been proposed to use the Vigi eNose® system (Chromatotec, Fr.), which can be applied both in emission and immission situations. This equipment consists of a gas chromatograph with a selective S detector (capable of sequentially measuring up to 14 individual VSCs in different points with a wide dynamic range and with a Limit of Detection, LD, between 0.5 and 8 ppbv). This system is supplemented with a Photoionization Detector (PID) that provides values assimilable to total VOC concentrations.
This system has been installed in the San Jerónimo WWTP (Seville, Spain), where 5 emission sources have been monitored, plus one immission point. The data generated by the Vigi eNose® are modelled in near real time and in forecast mode on the Meteosim online platform (Meteosim Solution®) using CALPUFF.
This paper presents data obtained over a month of monitoring, as well as the results of 3 sampling and analysis campaigns carried out in order to verify the applicability of the system. Monitoring data and campaign results showed a positive correlation between the different analytical techniques used.