Civil Engineering ETDs

Publication Date



Closing nutrient loops in terrestrial and aquatic ecosystems is integral to achieve resource security in the food-energy-water (FEW) nexus. Multiyear (2005-08), monthly samples of instream dissolved inorganic nutrient concentrations (NH4-N, NO3-N, soluble reactive phosphorus-SRP) along a ~300-km of the Rio Grande, NM, USA were used to investigate how the net source/sink behavior of wastewater and irrigated agriculture can be holistically managed to close nutrient loops. Wastewater on average contributed over 90% of the instream dissolved inorganic nutrients (101 kg/day NH4-N, 1097 kg/day NO3-N, 656 kg/day SRP). During growing seasons, the irrigation network downstream of wastewater outfalls retained on average 37% of NO3-N and 45% of SRP inputs, with maximum retention exceeding 60% and 80% of NO3-N and SRP inputs, respectively. Accurate quantification of NH4-N retention was hindered by low loading and high variability. This synoptic analysis is used to identify tradeoffs associated with wastewater reuse for agriculture within the scope of the FEW nexus and propose strategies for closing nutrient loops in arid-land rivers.


nutrients, food-energy-water nexus, wastewater reuse, Rio Grande


The National Science Foundation - Center for Water and the Environment (HRD-1345169)

Document Type




Degree Name

Civil Engineering

Level of Degree


Department Name

Civil Engineering

First Advisor

González-Pinzón, Ricardo

First Committee Member (Chair)

Van Horn, David

Second Committee Member

Schuler, Andrew