Performance and Sustainability Assessment of Full-Scale Sewage Treatment Plants in Northern India Using Multiple-Criteria Decision-Making Methods

In this study, an intensive performance assessment of 36 sewage treatment plants (STPs) is carried out. The STPs were based on the process technologies: moving-bed bioreactor (MBBR), sequencing batch reactor (SBR), waste stabilization pond (WSP), and upflow anaerobic sludge blanket reactor (UASB) with posttreatment technologies of extended aeration (EA), surface aeration, and polishing ponds, with treatment capacities of 3 to 40 million L per day. The pollutant removal performance of the STPs was ranked using the gray relational analysis method, which revealed that the SBR systems ranked higher, followed by UASB with EA, whereas MBBRs, UASB with other posttreatment options, and WSP performed satisfactorily to poor. Further, the preference ranking organization method for enrichment evaluation (PROMETHEE) multiple-criteria decision-making (MCDM) approach using the fuzzy analytic hierarchy process followed by preference ranking organization method for enrichment evaluation method evaluated the major wastewater treatment technologies using three sustainability criteria: environmental, economic, and technical aspects. The MCDM method evaluation revealed that the UASB + EA method, with its lower greenhouse gas emissions, energy requirement, sludge generation, and energy and resource recovery characteristics, outranked other treatment technologies, followed by SBR. The MCDM results were later confirmed using geometrical analysis for the interactive aid method. Hence, this study summarizes that the anaerobic process followed by microaerobic technologies still possesses the capability to achieve stringent disposal standards almost equivalent to intensive aerobic technologies.