Increased Detection of Desulfobacterota in Wastewater Treat-ment Plant Effluent via Composite Sampling Versus Grab Sampling

Municipal wastewater surveillance is essential for public health monitoring and preventing environmental contamination. Analysing treatment plant influents offers insights into population exposure to chemicals and microbes, while effluent and biosolids reflect treatment efficiency and the quality of substances released into the environment. Our study, which compared grab and 24-hour composite bacterial sampling methods using next-generation sequencing of the 16S V4 region, offers practical insights. We collected samples from influent, biosolids from the activated sludge process, and effluent wastewater on eight dates in 2017-2018 at wastewater treatment plants in Pirkanmaa, Finland.