This study compared the effects of soil texture, soil depth, and additional treatment, by constructed wetland (CW) and recirculating sand filter (RSF) systems, on wastewater renovation in a texture group 2 (loam) and a texture group 3 (clay loam) soil. The soils with depths of 15, 30, and 45 cm were placed in the columns with a Gidding's hydraulic soil probe in order to retain the soils structure <i>in situ</i>. The texture group 2 columns were dosed with septic tank eflluent (STE), constructed wetland effluent (eWE), and recirculating sand filter effluent (RSFE) at 685 cm³ per day and the texture group 3 columns were dosed at 670 cm³ per day with the same effluents. These dosing events were split into 2 separate (12 h) events. The leachate from both groups of soil columns were analyzed for fecal coliforms (FC), biochemical oxygen demand (BODs), ammonium (NH₄-N), nitrate (NO₃-N), phosphate (PO₄-P), pH, total dissolved solids (TDS), electrical conductivity (EC), and chloride.
In the texture group 2 soil the reduction in fecal coliform numbers was 88% and 99%, respectively, for the CW and the RSF and, in the texture group 3 soil was 91% and 99%, respectively, for the CW and the RSF. There was a reduction in BODs concentrations of 32% and 69% ,respectively, for the CW and the RSF. There was a 42% and 84% decrease in NH₄ concentrations, respectively, for the CW and the RSF. These reductions show that treatment of STE by CW or RSF can be substituted for soil depth in texture group 2 and 3 soils and will improve drainfield performance. Texture group 2 soils are less effective at STE renovation than texture group 3 soils at all soil depths. This was evidenced by higher FC counts and concentrations of BOD, N, and P in the leachates from these columns. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/42906 |
| Date | 08 June 2009 |
| Creators | Keeling, William G. |
| Contributors | Crop and Soil Environmental Sciences, Reneau, Raymond B. Jr., Hagedorn, Charles III, Martens, David C. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | viii, 117 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 34619211, LD5655.V855_1995.K445.pdf |
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