Sustainability assessment using multicriteria analysis for wastewater handling

Abstract

This study presents a sustainability assessment of three wastewater treatment technologies— Activated Sludge (AS), Membrane Bioreactor (MBR), and Aerobic Granular Sludge (AGS)— using the case of the Västra Stranden Wastewater Treatment Plant (WWTP) in Halmstad, Sweden. A Multi-Criteria Decision Analysis (MCDA) approach was applied to evaluate and compare the technologies across environmental, economic, technical, and social dimensions. Two different weighting methods were tested: a traditional percentage-based model and a value-based model using Weighted Score Ratios (WSR). Data collection included quantifiable performance indicators, expert judgment from professionals at Laholmsbuktens VA (LBVA), and input from students in an advanced wastewater engineering course. The value-based model assigns monetary values to each sustainability criterion, helping to clarify trade-offs and improve transparency in the decision-making process. Results from both workshops showed that the value-based approach was more effective in identifying which criteria had the greatest influence on overall sustainability. This study highlights the strengths of combining technical data with structured stakeholder input and suggests that value-based MCDA models can support more robust and balanced decisions in wastewater planning.