MANAGEMENT AND TREATMENT OF ODOUR NUISANCE IN LOMBARDY REGION: SURVEY OF 35 WASTEWATER TREATMENT PLANTS

Abstract

The odour emissions, generated by wastewater treatment plants, represent a current issue of great concern among the managers of the plants who must face this problem without any help by national regulation. The Lombardy Region guidelines partially fill in this gap in the law and the authors’ attention is focused on 35 plants of various potentiality belonging to four different areas of this Region. Through a checklist, information about the most widespread management and technological measures used to solve this problem has been collected. For each section of the plant, the carried out actions and the obtained results have been reported: the units, which are most affected by odour nuisance, are pre-treatments and dewatering, while the most used technology is multistage scrubber, often chosen because considered as very interesting from the point of view of cheapness/performance ratio. In order to find a relationship between managers’ warning (about seasonal and daily occurrence of odour events) and the parameters associated with atmospheric diffusivity, a model simulation has been done by using CALPUFF and the data of Arconate weather station: while the day-night cycle represents an element of great importance to explain the odour concentrations dynamics, seasonality, on the contrary, seems to be quite negligible. The present work aims at providing the lawmaker with a picture of the state of the art of odour problem in a large part of the Lombardy Region, in order to help him to adopt a new law which could guide the managers towards successful and aware decisions to properly manage the “odour problem”.