The Research Dialogue

Author(s) :Sarvesh Rai¹, Rajesh Kumar²

DOI: https://doi.org/10.64880/theresearchdialogue.v5i2.33

Abstract

Rapid urbanization and the expansion of sewerage infrastructure have significantly increased municipal wastewater generation, necessitating the deployment of efficient and sustainable sewage treatment technologies. Prayagraj, a major city situated at the confluence of the Ganga and Yamuna rivers, has implemented multiple sewage treatment plants (STPs) employing diverse biological treatment processes under the Namami Gange Programme. This study presents a comparative assessment of the principal sewage treatment technologies currently adopted in Prayagraj, including Upflow Anaerobic Sludge Blanket (UASB), Activated Sludge Process (ASP), Sequencing Batch Reactor (SBR), Fluidized Aerobic Bioreactor (FAB), and Biotower coupled with Activated Sludge Process (Biotower + ASP). Their performance was evaluated using published operational data and technical literature with respect to pollutant removal efficiency, nutrient removal, hydraulic retention time, energy consumption, land requirement, sludge production, greenhouse gas implications, resource recovery potential, lifecycle cost, and operational sustainability. The analysis indicates that SBR systems consistently achieve the highest removal efficiencies for biochemical oxygen demand (95–98%), chemical oxygen demand (90–94%), total suspended solids (95–99%), and nutrients, although they incur greater energy consumption and operational complexity. UASB-based systems demonstrate the lowest energy demand and offer the additional advantage of methane recovery, making them economically attractive for tropical regions despite comparatively lower treatment efficiencies when operated without advanced post-treatment. FAB and Biotower + ASP systems provide balanced performance with relatively compact footprints and stable operation under variable hydraulic loading. Comparative evidence from the Ganga River basin further highlights that long-term treatment performance depends not only on process selection but also on plant operation, maintenance, and local site conditions. Overall, the study demonstrates that technology selection for municipal wastewater treatment should integrate treatment efficiency with lifecycle sustainability, energy demand, resource recovery, and regulatory compliance rather than relying solely on conventional pollutant removal metrics. The findings provide technical guidance for optimizing existing STPs and for selecting appropriate treatment technologies in future urban wastewater infrastructure projects across India and other tropical developing regions.

Keywords

Sewage treatment plants (STPs), Sequencing Batch Reactor (SBR), Upflow Anaerobic Sludge Blanket (UASB), Activated Sludge Process (ASP), Fluidized Aerobic Bioreactor (FAB), Biotower, Energy consumption, Resource recovery, Namami Gange, Prayagraj

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