Characterization of odours emitted by liquid waste treatment plants (LWTPs)

Abstract

<p>Odour emissions from liquid waste treatment plants (LWTPs) generally cause significant effects on the environment in terms of nuisance to exposed population. The particular and complex nature of the mixture of the volatile substances, its variability in time and the strong influence of the atmospheric conditions, are the elements that delayed their regulation and relative management.</p> <p>Limited data are available in the technical and scientific literature, regarding the odour emissions characterization from liquid waste treatment plants. Moreover there isn’t a common strategy from the different European Countries in the regulation of their emissions.</p> <p>Different methods can be used to measure odour emissions from environmental engineering plants, and currently, in Europe, the most used techniques for odour emissions characterization and quantification is the dynamic olfactometry, according to EN 13725:2003.</p> <p>The aim of this study is the characterization of the odour emissions from different liquid waste treatment plants (LWTPs), trough a case study of two large real LWTPs, in order to identify the principal odour sources and to define their related odour emissions.</p> <p>Odour Concentration Index (OCI) is proposed as a useful and simply odour management tool for the identification of the priority actions necessary to identify and control the main odorous sources. Relationship between the measured odour emissions and the types of treated liquid waste (identified in terms of EWC code, COD and NH4<sup>+</sup>) is also discussed.</p> <p>Results show that the influent collection tank is the source with the highest detected odour emissions. OCI results are useful for the definition of a clear priority action for odour control, similar for both investigated plants. Between the characterized types of liquid waste treated by LWTPs the leachate (EWC 190703) show the maximum odour emissions.</p>