Wastewater Derived Dissolved Organic Nitrogen Removal using Integrated System of Biological Reactors and UV light Irradiation

Understanding the biodegradability, bioavailability, and photodegradability characteristics of wastewater derived dissolved organic nitrogen (DON) is important in achieving successful removal of DON using bacteria, algae, and UV light. Biodegradable DON (BDON) is the portion of DON that is degraded by bacteria while bioavailable DON (ABDON) is a portion of DON utilized by algae + bacteria. Photodegradable DON (PDON) is a portion of DON that is decomposable by sunlight or artificial light to lower molecular weight organic compounds. An integrated system has been devised using moving bed biofilm reactor (MBBR) media to support the growth of bacteria and algae + bacteria in two different reactors connected in series. Further UV light irradiations were implemented on the samples. BDON and ABDON were not consistent with hydraulic retention times (HRTs). The lowest average BDON and PDON were recorded as 1.86 and 0.50 mg/L in a three (3) days of HRT.