Multi-Criteria Decision-Making in Wastewater Treatment Systems

Multi-criteria decision-making (MCDM) in wastewater treatment addresses the challenge of evaluating and ranking diverse treatment pathways according to environmental, economic, technical and social objectives. With rapid urbanisation, stringent effluent standards and resource constraints, water utilities and planners must balance trade-offs between cost, performance, resource recovery and sustainability. MCDM frameworks structure decision problems by defining criteria, assigning relative weights and applying ranking algorithms to identify optimal solutions. Commonly employed techniques include the Analytic Hierarchy Process (AHP) for weighting, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and VIKOR for compromise ranking, as well as fuzzy logic extensions to handle uncertainty in expert judgements. Hybrid models integrate simulation tools with MCDM to capture process dynamics and environmental impacts, while stakeholder engagement ensures that local priorities and regulatory requirements are incorporated. Recent advances have explored psychological factors governing decision-maker risk aversion, incorporated α-cut fuzzy sets to refine criterion interactions, and developed user-friendly decision support systems for water authorities. Global applications span municipal centralised systems, decentralised on-site designs and industrial effluent reuse, demonstrating the flexibility of MCDM in guiding technology selection, resource optimisation and sustainable asset management across diverse contexts.

Research from Nature Portfolio

Recent studies have introduced a hybrid fuzzy decision-making framework that combines the Analytic Hierarchy Process (AHP) with the TODIM method under an α-cut series to account for decision-maker risk aversion and uncertainty. By interpreting criterion interactions through membership functions rooted in prospect theory, the model generates dominance degrees that enable a nuanced ranking of treatment technologies. Application to full-scale wastewater treatment plants in a metropolitan context revealed that the anaerobic–anoxic–oxic process without pre-clarification maximised sustainability performance under sludge disposal cost criteria. This work underscores the value of integrating psychological insights with fuzzy MCDM to support technology selection in complex urban environments.

Multi-Criteria Decision-Making in Wastewater Treatment Systems publication trend

The graph below shows the total number of articles in multi-criteria decision-making in wastewater treatment systems across all publications each year (not limited to Nature Index journals).

Technical terms

Multi-Criteria Decision-Making (MCDM): A structured approach for evaluating and ranking alternatives that considers multiple conflicting objectives and stakeholder preferences.

Analytic Hierarchy Process (AHP): A pairwise comparison method used to derive relative weights for decision criteria based on expert judgements.

Technique for Order Preference by Similarity to Ideal Solution (TOPSIS): A ranking technique that identifies solutions closest to an ideal reference point and farthest from a nadir point.

Fuzzy sets: Mathematical constructs representing imprecise or uncertain information through degrees of membership between zero and one.

TODIM: A multi-criteria method grounded in prospect theory that calculates dominance degrees for alternatives, reflecting decision-maker risk attitudes.

References

1. Multi-attribute sustainability assessment of wastewater treatment technologies using combined fuzzy multi-criteria decision-making techniques. Journal of Cleaner Production (2022).
2. Designing a Sustainability Assessment Framework for Selecting Sustainable Wastewater Treatment Technologies in Corporate Asset Decisions. Sustainability (2021).
3. A novel fuzzy framework for technology selection of sustainable wastewater treatment plants based on TODIM methodology in developing urban areas. Scientific Reports (2022).