Sustainability evaluation of a water-bound bring collection system for recyclable waste: optimization strategies and real-world application

This study focuses on the implementation of a water-bound recyclable waste collection service using a barge as a mobile collection site and quays as temporary assembly points. We formulate generic mixed-integer linear programs and solve these with real-world data from a pilot study in Stockholm. This public waste collection service aims to increase collection and recycling rates of valuable fractions, as well as reduce the strain on urban infrastructure. Our two-stage modelling approach maximizes the coverage of the supply and minimizes the emissions of the barge’s route, including transshipment points and road transport to recycling centers. Through extensive numerical analyses, we assess the social and environmental impact of a visit spacing policy and increased storage capacities on the barge. The findings reveal trade-offs between the transport modes, road and water, and social accessibility and emission reductions. For example, the integration of transshipment points causes more emissions on water but can mitigate the negative externalities of road transport by reducing transport trips. The study offers a sustainability evaluation of the collection system’s operation to support informed decision-making by city administrations and sustainable urban logistics planning.