| Due to the increased concern on dissolved organic nitrogen (DON) in surface waters, it is necessary to understand the biodegradability and bioavailability of DON in point and non-point sources. In this study, biodegradable DON (BDON) was determined using bacteria while bioavailable DON (ABDON) was determined using green algae Selenastrum capricornutum, Chlamydomonas reinhardtii, and Chlorella vulgaris and/or mixed culture bacteria in municipal and animal wastewaters. In both wastewater sources, ABDON efficiencies (%) for all three algae were not significantly different indicating that Chlamydomonas reinhardtii and Chlorella vulgaris can be used as a test species for nitrogen determination similar to Selenastrum capricornutum. Results showed that, the ranges of BDON and ABDON in municipal wastewaters were 50-60% and 30-77%, respectively, while the ranges of BDON and ABDON in animal wastewaters were 48-54% and 40-81%, respectively. |
