The limited availability of water and stringent wastewater effluent standards at rest areas led to the development of a water recycle-reuse system to treat flush water from water closets. Prior research with a bench-scale system confirmed the application of extended aeration biological treatment followed by granular media filtration as a water recycle-reuse concept. This prior work led to the installation of a full-scale field system at a rest area to develop data for implementation of the recycle concept. The treatment system at an existing rest area was modified to provide a closed loop return of water to and from the water closets. A water balance was achieved by wasting an amount of recycle water equal to the water input from sewered potable water. Operation of the closed loop extended aeration and granualr filter system for flush water recycle and reuse was similar to the conventional operation of these processes. The influence of nitropgen accounted for the most significant operating difference. Ammonia nitrogen transformation to nitrite and nitrate nitrogen resulted in an operating pH of 5.5 to 6.0 and, as a result, incomplete nitrification occurred. Nitrogen buildup in the form of ammonia, nitrite, and nitrate was experienced but the concontrations did not cause a reduction in the organic biological oxidation efficiency. The biological system functioned under conditions suitable for the utilization of organics by fungi. The biological solids were threadlike; however, they readily separated through gravity settling.

  • Record URL:
  • Supplemental Notes:
    • This report was prepared in cooperation with the U.S. Department of Transportation, Federal Highway Administration.
  • Corporate Authors:

    Virginia Highway and Transportation Research Council

    Charlottesville, VA  United States 
  • Authors:
    • Parker, C E
  • Publication Date: 1977-12

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 79 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00172872
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: VHTRC 78-R22
  • Created Date: Apr 12 1978 12:00AM