Towards zero marine plastic pollution: a multidimensional measurement model for evaluating waste management solutions informed by SDGs 12 and 14

Purpose: This paper explores how marine plastic waste management solutions can be holistically evaluated in alignment with Sustainable Development Goals (SDGs) 12 and 14. It aims to address the fragmentation in the existing literature by developing an integrated model for sustainability assessment that combines cost-benefit analysis (CBA) and multi-criteria decision analysis (MCDA). Design/methodology/approach: Presenting an interventionist case study, the research examines a project aimed at collecting plastic waste from the sea and constructing a pyrolysis plant to convert non-recyclable plastics into energy in a major Italian port. A multidimensional evaluation model was developed through iterative stakeholder engagement, integrating financial and non-financial criteria across economic, environmental, and social dimensions to assess the investment. Data were gathered through semi-structured interviews, document analysis and field observations. Findings: The study introduces an integrated CBA–MCDA framework tailored to the complexities of sustainability-oriented investments. The model enables a comprehensive assessment of infrastructure projects by combining economic valuation with participatory evaluation of qualitative impacts. It also strengthens alignment with the targets of SDGs 12 and SDG 14 by incorporating criteria related to waste recovery, emissions reduction and social outcomes. Originality/value: This research contributes to the literature by operationalising the interdependence between SDGs 12 and 14 within a unified decision-making framework. It advances existing approaches by demonstrating how integrated methodologies can support investment decisions in contexts where environmental, economic, and social objectives converge, offering a replicable model for sustainability evaluation in waste management.