Collaborative Research: Assessing the bioavailability of effluent organic nitrogen along a freshwater to saltwater continuum

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

CBET-0755308 Love The objective of this proposed study is to address the bioavailability of effluent organic nitrogen (EON)) wastewater treatment facilities which provides biological nutrient removal. The research is intended to provide basic information that can lead to reliable bioassays to determine the effect of a wastewater plant discharge EON on the receiving surface water and contribution to eutrophication. An excellent background on known factors that affect the availability of organic nitrogen in surface waters was presented and reflected the diverse backgrounds of this collaborative research group; environmental engineer, biological oceanographer, organic geochemists, and chemical oceanographer. Basic hypothesis for the research is that the bioavailability of EON is related to salinity concentration and light and that the biota in the surface water may be different at different salinity locations and possibly have different EON conversion and uptake characteristics. The research would investigate the effect of different seed sources on the EON bioavailability. The proposal provides a plan to assess the biological populations, the level of algae growth by. Chlorophyll á measurement, the availability of the EON based on molecular weight size, and application of chemistry methods to assess the elemental composition of the EON and molecular characterization. The ability to develop a bioassay for the bioavailability of EON and to determine what amount from wastewater plant effluents is biodegradable will have far reaching impacts. First it would provide water quality managers and modelers scientific basis on whether to treat all effluent nitrogen as bioavailable as they now do or to account for a possible recalcitrant fraction that has not affect on eutrophication activity and thus does not contribute to developing hypoxia conditions that are harmful to fish. The bioassay tool can help guide wastewater plant designs as effluents from different operations can be used to determine if different design or operating conditions affect the EON bioavailability. Other important impacts are a summer mini school that can use this project and water quality issues in the Chesapeake Bay area as local and real scenario for study by the public. The work will be showcase and model for interdisciplinary research on a large scale problem. This type of training and education will have a long term impact on the graduate students working on the project. The PIs have also had successful summer research experiences for undergraduates as part of past NSF studies.