Nitrification Kinetics of a Full-scale, Low DO Activated Sludge System: Online Monitoring for Process Analysis and Operational Training

Black & Veatch (BV) in collaboration with the Trinity River Authority of Texas (TRA) at the Central Regional Wastewater System treatment plant (CRWS) developed an implementation plan of the in-tank nitrification rate (INR) reactor. Nitrification rate testing is a tool to assist with early identification of process health and identify variability in nitrification kinetics in a low dissolved oxygen (DO) activated sludge system. The TRA CRWS facility currently operates the secondary system in a low DO environment with ammonium-based airflow controls (ABAC). A low DO comammox Nitrospira nitrifying community has been documented at the facility. The INR reactor was proposed as a measure that allows TRA CRWS operation to monitor the health of the overall activated sludge bacterial community health continuously without adding the burden of monitoring and sampling on the operators.