Graduate Thesis Or Dissertation
 

Nitrogen recovery from simulated sand-filter effluent by grass

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/12579w12c

Descriptions

Attribute NameValues
Creator
Abstract
  • The effluent from on-site sewage disposal systems has been found to be a source of nitrates (NO ₃⁻ ) in groundwater. Vegetation has the ability to remove some of the nitrogen (N) from sewage effluent as the solution moves through the soil around a disposal trench, before it reaches groundwater. Shallow aquifers are particularly susceptible to NO₃⁻ contamination under on-site sewage disposal systems in permeable, coarse-textured soils. This is due to the relatively rapid downward movement of leachate from a disposal trench, and to the shorter trench length allowed in these soils. The objective of this study was to determine if reducing the effluent application rate, in a coarse-textured soil, would increase the percent of N that grass could recover from the effluent. The potential NO ₃⁻ toxicity of the grass was also considered. A solution with a NO ₃ ⁻N concentration of 30 mg/L was introduced through shallow disposal trenches into a sandy soil vegetated with tall fescue (Festuca arundinacea Schreb.). The NO ₃⁻ solution simulated sand-filter effluent, since the primary contaminant of sand -f liter effluent is NO ₃⁻. Four treatments were used with three replications of each treatment. Three treatments received the NO ₃⁻ solution. The daily application rates of this solution were 25.2, 12.6 and 6.3 L/m of disposal trench for the high-, medium-, and low-rate treatments, respectively. The fourth treatment received water only, as a control. The application rate of solution for the high-rate treatment matched the mean application rate for sand-filter effluent in a sandy soil. The grass that grew in response to the NO₃⁻ solution seeping out from the trenches was harvested 3 times during the 134 day study period. The three cuttings from each plot were mixed and a subsample from each was tested for total-N, NO₃⁻N and other nutrients. Reducing the effluent application rate did not significantly change the percent of N recovered from the effluent. The mean (± S.E.) percent N recovery ranged from 25.1 ± 1.8% for the low-rate treatment to 31.7 ± 0.6% for the medium-rate treatment. The mean NO ₃⁻ concentration of the grass from the high-rate treatment was 3100 ± 265 ppm. At this NO₃-N concentration the percent NO ₃⁻ in the grass is 1.36%. If this grass made up the entire ration of an animal, NO₃⁻ poisoning could occur.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details HallThomasD1984.pdf 2017-08-16 Public Download