PURETEC SYSTEM FOR TREATMENT OF SHIPBOARD WASTE

As part of the national objective of cleaning up our environment, ship and boat owners will be required in the near future to drastically curtail or eliminate the discharge of human waste into the navigable waters of the United States. A recent paper presented to this society by H.N. Wallin summarized the marine waste treatment regulations and described various types of sewage treatment systems that may be useful in a marine environment. In that presentation, the anticipated requirements were summarized. This paper describes some of our work on wet oxidation of shipboard sewage and its application to the "No Discharge" requirement that may be mandatory in the near future. Under the "No Discharge" rules, the number of possible ways in which shipboard sewage can be handled are limited. The possible methods that have been considered include: (1) holding tanks, (2) evaporation/incineration, and (3) closed circuit wet oxidation. Holding tanks require substantial space but require little attention from the crew while underway. Modest aeration is required and the tanks must be vented to prevent the objectionable odors of anaerobic bacterial growth and the explosion hazards of evolved methane. Only capacity limits the time between pump-outs and dockside facilities must be available for discharge. The evaporation/incineration systems are somewhat more complex in operation and some versions require the use of substantial quantities of energy to evaporate the water or reduce the water content of the sludge. Problems have been encountered with odors but use of gas treatment systems, such as catalytic after-burners, has reportedly solved this problem. Evaporation of fecal material and urine, especially in the presence of sea water, causes build-up of scale and/or char on the heated surface, requiring frequent cleaning if system efficiency is to be maintained. Wet oxidation, the subject of this paper, seems uniquely applicable for the on-board processing of marine sanitary waste. The process is simple, adaptable to closed-loop (no discharge) or open-loop operation. If ultimately required, galley waste can be added to the system with minor modifications.

  • Supplemental Notes:
    • Presented at the Los Angeles Metropolitan Section Meeting of SNAME.
  • Corporate Authors:

    Society of Naval Architects and Marine Engineers

    601 Pavonia Avenue
    Jersey City, NJ  USA  07306-2907
  • Authors:
    • Fassell, W M
    • Bridges, D W
  • Publication Date: 1973-11-8

Media Info

  • Features: References;
  • Pagination: 21 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00053936
  • Record Type: Publication
  • Source Agency: Society of Naval Architects and Marine Engineers
  • Files: TRIS
  • Created Date: May 7 1974 12:00AM