Impact of Operational Conditions on Pathogen Removal Efficiency in Sequencing Batch Reactors

Increasing wastewater generation, microbial contamination, and the growing demand for safe water reuse have created a critical need for advanced and sustainable wastewater treatment technologies. Conventional biological treatment systems are primarily designed for organic pollutant removal and often exhibit inadequate pathogen removal efficiency under fluctuating operational conditions. Sequencing Batch Reactor (SBR) technology has emerged as a promising biological treatment system due to its operational flexibility, compact configuration, and enhanced treatment performance. The present study experimentally investigates the influence of key operational parameters on pathogen removal efficiency in a lab-scale Sequencing Batch Reactor treating municipal wastewater. The effects of Hydraulic Retention Time (HRT), Dissolved Oxygen (DO), Mixed Liquor Suspended Solids (MLSS), and cycle duration were systematically evaluated under controlled laboratory conditions. Microbial indicators including Escherichia coli and total coliforms were analyzed along with physicochemical parameters such as Chemical Oxygen Demand (COD), pH, and dissolved oxygen. The experimental results are expected to identify the optimum operating conditions for maximizing pathogen removal while maintaining efficient organic pollutant degradation. Statistical analysis and regression modelling will be used to establish relationships between operational parameters and microbial removal efficiency. The study is also expected to demonstrate that optimization of HRT, DO, and MLSS significantly improves biological treatment performance, reduces pathogenic contamination, and enhances process stability without requiring major infrastructure modifications. The findings of this research will contribute to the design and operation of more efficient Sequencing Batch Reactor systems for municipal and industrial wastewater treatment. The optimized operational conditions developed through this investigation can assist engineers, researchers, and wastewater treatment plant operators in improving treatment efficiency, ensuring compliance with regulatory discharge standards, and promoting safe wastewater reuse. Furthermore, the outcomes support sustainable water resource management and contribute towards achieving Sustainable Development Goal 6 (Clean Water and Sanitation) by enhancing the microbiological safety of treated wastewater.