Location: Cereal Crops Research
Title: Bioavailability of dissolved organic nitrogen (DON) in wastewaters from animal feedlots and storage lagoonsAuthor
SUN, JINGYI - North Dakota State University | |
KHAN, EAKALAK - North Dakota State University | |
SIMSEK, SENAY - North Dakota State University | |
Ohm, Jae-Bom | |
SIMSEK, HALIS - North Dakota State University |
Submitted to: Chemosphere
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/29/2017 Publication Date: 8/1/2017 Publication URL: http://handle.nal.usda.gov/10113/5801897 Citation: Sun, J., Khan, E., Simsek, S., Ohm, J.-B., Simsek, H. 2017. Bioavailability of dissolved organic nitrogen (DON) in wastewaters from animal feedlots and storage lagoons. Chemosphere. 186:695-701. https://doi.org/10.1016/j.chemosphere.2017.07.153. DOI: https://doi.org/10.1016/j.chemosphere.2017.07.153 Interpretive Summary: The dissolved organic nitrogen (DON) from animal waste can lead to overabundance of algal growth and depletion of dissolved oxygen in surface waters, which cause negative influence on aquatic environment. Biodegradable DON (BDON) is a portion of DON that is mineralized by bacteria while bioavailable DON (ABDON) is utilized by bacteria and/or algae for their growth. This study determined DON, BDON, and ABDON in animal wastewaters collected from two different sources: an animal feedlot wastewater storage tank and a sheep wastewater storage lagoon. Two algal species, mixed culture bacteria and their combinations were tested to determine the levels of DON that they utilize for growth in the waste water samples. The results showed that 3.21 to 5.87 mg-N/L (51.3 to 78.9% of initial DON) of DON in animal feedlot samples and 3.44 to 7.54 mg-N/L (40.5% to 80.9% of initial DON) of DON in storage lagoon wastewater samples were consumed by any combination of algae and bacteria used in this study. These results suggest that the DON in livestock wastewater should be another important factor influencing the growth of algae and bacteria in addition to other obvious culprits, ammonia and nitrate. Technical Abstract: Dissolved organic nitrogen (DON) transport from animal agriculture to surface waters can lead to eutrophication and dissolved oxygen depletion. Biodegradable DON (BDON) is a portion of DON that is mineralized by bacteria while bioavailable DON (ABDON) is utilized by bacteria and/or algae. This study determined DON, BDON, and ABDON in animal wastewaters collected from two different sources: an animal feedlot wastewater storage tank and a sheep wastewater storage lagoon. Two algal species, Chlamydomonas reinhardtii and Chlorella vulgaris, mixed culture bacteria and their combinations were used as test species for BDON and ABDON bioassays. The results showed that 3.21 to 5.87 mg-N/L (51.3 to 78.9% of initial DON) of DON in animal feedlot samples and 3.44 to 7.54 mg-N/L (40.5% to 80.9% of initial DON) of DON in storage lagoon wastewater samples were bioavailable to any combination of algae and bacteria used in this study. These results suggest that when considering eutrophication potential of livestock wastewater, organic nitrogen should be included in addition to obvious culprits, ammonia and nitrate. |