Multicriteria Analysis of Decentralized Wastewater Treatment Technologies for the Philippines

This research focuses on decentralized wastewater treatment (DEWAT) technologies for the Philippines that is motivated by the limited suitable wastewater treatment infrastructure in the country. A multi-criteria analysis (MCA), using the Analytic Hierarchy Process (AHP) and Delphi method, was employed to evaluate DEWAT technologies based on life cycle costs and wastewater treatment efficiency parameters such as CODt, BOD5, TSS, NH4-N, TP, and hydraulic retention time. A two-factor Analysis of Variance (ANOVA) without replication was used to assess statistical differences between technologies. The analysis revealed that the Downflow Hanging Sponge (DHS) filter, Multi-Soil Layering (MSL) systems, and Moving Bed Biofilm Reactors (MBBRs) are the top-performing technologies, with no statistically significant differences in their overall performance. The DHS filter ranked highest, excelling in energy efficiency and nutrient removal, making it ideal for resource-scarce environments. MSL systems were noted for their broad-spectrum contaminant removal, while MBBRs demonstrated flexibility and scalability for semi-urban areas. A thorough analysis is carried out for these DEWAT technologies and insights for applicability in the Philippine context are provided.