Comparative Study of Conventional and Modern Sewage Treatment Technologies

This study presents a comprehensive comparative evaluation of six major sewage treatment technologies—Activated Sludge Process (ASP), Moving Bed Biofilm Reactor (MBBR), Sequential Batch Reactor (SBR), Upflow Anaerobic Sludge Blanket with Extended Aeration (UASB+EA), Membrane Bioreactor (MBR), and Bio-Digester & Bio-Remediation (BDBR)— based on key performance indicators including biological oxygen demand (BOD), total suspended solids (TSS), faecal coliform removal, total nitrogen (T-N) removal efficiency, land area requirement, capital costs, energy consumption, and operation and maintenance (O&M) costs. The analysis reveals that while technologies like SBR and MBR show superior treatment efficiencies in terms of BOD, TSS, and nutrient removal, their energy demand and capital investment are significantly higher. In contrast, conventional methods such as ASP and UASB+EA, although cost-effective and simple in design, fail to meet stricter effluent quality norms without post-treatment polishing. MBBR presents a balanced option in terms of footprint and performance but still requires downstream filtration. The BDBR technology emerges as a highly promising alternative, offering excellent effluent quality with BOD and TSS values consistently below 10 mg/L and total nitrogen removal up to 80%, while simultaneously minimizing land requirement, capital investment, energy costs, and operational complexity. Its decentralized applicability, reduced dependency on skilled labor, and capability for biogas generation position it as a sustainable, eco-friendly, and costefficient solution, especially for small to medium-sized communities. Thus, the performance comparison highlights that while each technology has its merits, BDBR offers the most optimal combination of environmental and economic viability, making it the most suitable choice for municipal wastewater management in developing regions.