325-2 A Model to Predict Nitrogen Losses in Advanced Soil-Based Wwastewater Treatment Systems.

Poster Number 1506

See more from this Division: SSSA Division: Urban and Anthropogenic Soils
See more from this Session: Urban and Anthropogenic Soils: II

Tuesday, November 17, 2015
Minneapolis Convention Center, Exhibit Hall BC

Ivan Morales, Civil and Environmental Engineering, University of Rhode Island, Kingston, RI, Jennifer Cooper, Soil and Water Science, University of Florida, Belle Glade, FL, George Loomis, NRS Department, New England Onsite Wastewater Training Center, Kingston, RI, David Kalen, New England Onsite Wastewater Training Center, Natural Resources Sciences, University of Rhode Island, Kingston, RI and Jose Adolfo Amador, University of Rhode Island, Kingston, RI
Abstract:

Most of the non-point source Nitrogen (N) load in rural areas is attributed to onsite wastewater treatment systems (OWTS). Nitrogen compounds are considered environmental pollutants because they deplete the oxygen availability in water bodies and produce eutrophication. The objective of this study was to simulate the fate and transport of Nitrogen in OWTS. The commercially-available 2D/3D HYDRUS software was used to develop a transport and fate model. Experimental data from a laboratory meso-cosm study included the soil moisture content, NH4 and NO3- data. That data set was used to calibrate the model. Three types of OWTS were simulated: (1) pipe-and-stone (P&S), (2) advanced soil drainfields, pressurized shallow narrow drainfield (SND) and (3) Geomat (GEO), a variation of SND. To better understand the nitrogen removal mechanism and the performance of OWTS technologies, replicate (n = 3) intact soil mesocosms were used with 15N-labelled nitrogen inputs. As a result, it was estimated that N removal by denitrification was predominant in P&S. However, it is suggested that N was removed by nitrification in SND and GEO. The calibrated model was used to estimate Nitrogen fluxes for both conventional and advanced OWTS. Also, the model predicted the N losses from nitrification and denitrification in all OWTS. These findings help to provide practitioners with guidelines to estimate N removal efficiencies for OWTS, and predict N loads and spatial distribution for identifying non-point sources.

See more from this Division: SSSA Division: Urban and Anthropogenic Soils
See more from this Session: Urban and Anthropogenic Soils: II