: Increasing water scarcity and climate variability are accelerating interest in decentralized water treatment strategies to enhance urban water resilience and support circular economy objectives. However, selecting appropriate technological configurations remains a complex decision-making challenge due to trade-offs among technical, economic, social, and resource recovery criteria. This study develops an integrated Multi-Criteria Decision Analysis (MCDA) framework that combines the Analytic Hierarchy Process (AHP) with the contextualized indicator structure of the Decision-Making for Sanitation and Resource Recovery Systems (DMsan) platform. The framework evaluates five decentralized wastewater treatment configurations: two vacuum-based systems with different anaerobic schemes (V1, V2), two conventional toilet-based systems with aerobic and anaerobic processes (C1, C2), and one source-separation system using urine-diverting toilets (UD). To capture different planning priorities, nine decision scenarios representing alternative policy and implementation contexts are analyzed. The assessment incorporates 21 indicators grouped into 4 criteria. The results reveal three distinct technological suitability profiles. The vacuum-based configuration V2 shows the most balanced performance and ranks highest in scenarios prioritizing operational resilience, social acceptance from a management perspective, and low operating costs. The conventional configuration C2 is preferred in scenarios dominated by financial feasibility and minimized capital investment. In contrast, the source-separation configuration UD outperforms other alternatives when circular economy objectives and maximum nutrient recovery are prioritized. The results demonstrate that technological suitability is strongly context-dependent and highlight the value of multi-scenario MCDA for supporting the planning and design of resilient and circular decentralized urban water systems.
Cardozo et al. (Fri,) studied this question.