Odour emissions from wastewater treatment process (WWTP) are a relevant environmental issue, particularly in densely populated areas. However, the wastewater treatment process allows for a reduction in the pollutant load and a mitigation of the odour load of the wastewater itself. This study presents an experimental monitoring campaign aimed at assessing odour emissions associated with liquid wastewater streams and sludge in a municipal WWTP. Odour emission capacity (OEC) analyses are carried out on liquid effluents at different stages of the treatment process, alongside chemical characterisation and dynamic olfactometry. The approach enabled the evaluation of the distribution of odorous compounds throughout the treatment line and their potential contribution to emission fluxes. The results highlight a decrease in OEC between influent and treated effluent, with values decreasing from 105 ouE/m3 to 104 ouE/m3 in the liquid phase. Evaluating the odour rate (ORL) of each sampling, the results show that the corresponding abatement efficiency is about 60%, alongside a redistribution of odorous compounds between the liquid and solid phases during treatment. Overall, the combined chemical and olfactometric data provide a coherent framework for interpreting odour emission patterns within the plant.
