Funding Opportunity: Bioavailability of Organic Nitrogen and Phosphorus in Wastewater

Deadline: 05-Oct-2026

The Water Research Foundation (WRF) is seeking research proposals to improve understanding of dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) in water resource recovery facilities (WRRFs). The research will examine their concentrations, chemical forms, bioavailability, transformation, and behavior in wastewater treatment systems and receiving waters. Applicants can request up to $275,000 in WRF funding, with an anticipated project duration of 24 to 36 months. Eligible applicants include U.S. and non-U.S. educational institutions, research organizations, government agencies, consultants, and other for-profit entities. What Is the WRF Research Project? This Water Research Foundation research opportunity focuses on dissolved organic nitrogen and dissolved organic phosphorus in wastewater resource recovery facilities. WRRFs process wastewater through multiple treatment stages and generate different process streams. DON and DOP can occur in: Influent wastewater. Treated effluent. Sidestreams. Other process streams within WRRFs. The project seeks to generate a better understanding of how these organic nutrient forms behave throughout treatment and after treated water enters receiving environments. What Are Dissolved Organic Nitrogen and Phosphorus? Dissolved organic nitrogen (DON) refers to nitrogen-containing organic compounds that are dissolved in water. Both can occur naturally or originate from wastewater and other anthropogenic sources. Their importance extends beyond simply measuring total nitrogen or phosphorus because their chemical form and bioavailability can influence how they behave during wastewater treatment and in receiving waters. Why Does This Research Matter? Understanding DON and DOP is important for improving wastewater treatment and protecting receiving waters. Traditional nutrient monitoring may not fully explain what happens to dissolved organic nutrient fractions after wastewater discharge. Better characterization could help utilities and researchers understand: How much DON and DOP is biologically available. How these compounds change during treatment. How they contribute to downstream nutrient cycling. Whether DON contributes to nitrogenous disinfection by-product formation. How quickly organic nutrient compounds biodegrade. The research could therefore support improved water quality management, wastewater treatment strategies, nutrient management, and environmental protection. What Are the Main Research Objectives? The project has several core objectives. Survey DON and DOP Concentrations Researchers will survey DON and DOP across a range of WRRF process streams. The research should characterize concentrations in locations such as: Influent. Effluent. Sidestreams. Other relevant treatment process streams. This will help establish a broader understanding of DON and DOP occurrence across different facilities and treatment conditions. Characterize DON and DOP Speciation Concentration alone does not provide a complete picture of organic nutrients. The research will therefore examine their speciation, meaning the different chemical forms in which DON and DOP occur. Understanding chemical composition can help determine how individual fractions behave during treatment and after discharge. Quantify the Bioavailable Fraction An important objective is to determine the proportion of DON and DOP that is bioavailable. Bioavailability refers to the fraction that organisms can use or transform through biological processes. Determining bioavailable fractions can improve understanding of the potential ecological effects of nutrient discharges. The research will examine whether DON can transform into nitrogenous disinfection by-product (N-DBP) precursors. This is important because organic nitrogen compounds can participate in reactions during water treatment and disinfection. Understanding these transformations could help utilities better evaluate water quality and treatment implications. Determine Bio-Uptake Rates Researchers will evaluate how quickly DON and DOP can be taken up biologically under receiving-water conditions. This can help determine how organic nutrients behave after treated wastewater enters rivers, streams, lakes, or other receiving environments. Measure Biodegradation Timescales The project will also examine how quickly DON and DOP biodegrade in receiving waters. Understanding biodegradation timescales can help researchers predict: Nutrient persistence. Transformation pathways. Biological availability. Downstream water-quality effects. What Research Approach Is Expected? The project is expected to combine characterization and experimental research.

A research team may need to:

Survey DON and DOP concentrations across WRRF process streams. Characterize their chemical forms. Determine bioavailable fractions. Examine transformation pathways. Evaluate N-DBP precursor formation. Test biological uptake under receiving-water conditions. Measure biodegradation rates and timescales. Translate findings into information useful to water utilities and researchers. The final research should improve practical understanding of the fate and transformation of dissolved organic nutrients. Who Is Eligible to Apply? The opportunity is open to both U.S.-based and non-U.S.-based entities.

Eligible applicants can include:

Educational institutions. Universities. Research organizations. Governmental agencies. Consultants. Other for-profit entities. Applicants should have the scientific and technical capacity necessary to conduct research involving wastewater treatment, nutrient chemistry, environmental processes, or related fields. Who Is Not Eligible to Participate? Researchers who are late on ongoing WRF-sponsored studies without approved no-cost extensions are not eligible to be named as participants in proposals. Applicants should therefore confirm the status of any existing WRF-funded research before submitting a proposal. How Much Funding