Waste Characterization in the Urban Canal Network of Padova (italy) to Mitigate Downstream Marine Plastic Pollution

Concern about plastic pollution in coastal wetlands, seas and oceans has risen dramatically in recent years. Most of the waste found in the environment has a land-based origin and it is transported toward coastal-marine ecosystems through rivers and canals. Thus, waste collection in watercourses flowing through urban areas has a great potential to mitigate plastic pollution in local and coastal water bodies. In this paper, authors describe the results of three waste collection campaigns performed during 2021 (early summer, late summer and autumn) in three representative points of the channel network of the historical center of the city of Padova, Italy, where restoration efforts of the urban stream ecosystems are ongoing. The collected waste was analyzed both in terms of size and material type. A total of 418 kg of waste was collected: the prevailing fraction was the coarse one (59% of the material intercepted by a 100 mm side mesh sieve), and plastic represented the most abundant waste category (47% by weight). The total amount of litter produced in one year from the channel network of the city of Padova was estimated, with litter amounts on the canal banks found to be much higher than or at least comparable to those in water, a result which highlights the importance of planning waste collection together with riparian vegetation management to reduce plastic pollution. These findings provide a baseline for assessing the possibility to valorize the waste collected from the waterways of the city with processes other than landfilling and incineration