Method Development for Measuring Biodegradable Dissolved Organic Nitrogen in Treated Wastewater

A method for determining biodegradable dissolved organic nitrogen (BDON) in treated wastewater was developed. The method adopts the approaches used in the biochemical oxygen demand and biodegradable dissolved organic carbon tests to make it employable as a routine procedure at wastewater treatment plants. The development focused on various aspects of the procedure including inoculum type and concentration, incubation period, and the need for sample filtration after incubation. Results indicated that acclimated mixed liquor suspended solids diluted to a concentration of 240 mg/L was the best inoculum and an incubation period of 20 days was adequate for BDON exertion. The sample filtration after incubation was not required. Under these conditions, the developed BDON procedure provided accurate and precise BDON results.