Title : Towards improving urban waste management: Characterization and evaluation of odorous impact
Abstract:
One of the challenges that modern societies are facing nowadays is the development of strategies and tools for efficient urban waste management. In fact, the improvement of the valorization of urban waste is essential to promote circular economy and the implementation of the smart cities concept. In that context, an ambitious research study has been carried out in collaboration with the Municipal Sanitation Company of Córdoba (Spain) (SADECO, S.A.) and within the frame of the national R+D+i project PID2020-117438RB- I00 (MICINN). The investigation focuses on establishing the bases for efficient management strategies of urban solid waste, with the aim of valorizing and promoting the recirculation of the main nutrients, in parallel to reducing the odorous impact. The composition of 228 samples of urban solid waste withdrawn from containers for organic matter and packaging/inert materials (inorganic) in the city of Córdoba (South Spain; > 325,000 inhabitants) was analyzed. The evaluation was carried out through waste typology classification, physical-chemical characterization and dynamic olfactometry. Samples were collected throughout a 2-year period (at different seasons) and in the different districts of the city. The main results obtained show that the selective separation of urban solid waste by the inhabitants is not optimal, since 54% and 28% of the substrates are incorrectly deposited in the containers for inorganic and organic matter, respectively. Furthermore, no significant statistical differences have been detected among districts, neither in the typology of waste nor in their physical-chemical characterization (except for pH and total Kjeldahl nitrogen in samples withdrawn from inorganic containers). On the other hand, the evaluation of the emission of odors from waste through dynamic olfactometry shows a more marked impact derived from the organic fraction. The odorous impact has been related with higher concentrations of volatile solids, nitrogen and total soluble organic carbon in waste. These preliminary results highlight the need to promote citizen awareness on the importance of segregating waste in origin and its proper disposal to improve recycling and valorization of the different fractions of urban solid waste. Additionally, in order to mitigate the social impact derived from waste odorous emissions, an intelligent sensorized prototype is also being developed for early detection and management of odors along the chain links of waste collection (by minimizing the residence time in urban containers) and treatment.
