Re: another question

[asagady@sojourn.com]

  At 10:00 PM 11/7/97 -0500, Jon Campbell wrote:
  > Hi, folks,
  >
  >      Landfill gas is a source of dioxin, if burned,
  >because of the presence of vinyl chloride
  >monomer, which comes from deteriorating
  >PVC. Typical flaring is very low temperature,
  >and incomplete combustion, giving rise to
  >particulates of elemental carbon and PAH,
  >and polychlorinated phenols.
  >
  >Jon
  
  Gee Jon....there's a lot of assumptions here.   But 
  do you have any data?   If you read carefully some
  of what Pat Costner posted, the most quantitative
  information there was based on assumptions and
  not actual test data.   I know because I found the
  same hit that Pat did and read the parts that weren't
  posted in Pat's message.   The author of that material
  was also making the argument that recycling MSW
  causes worse contamination problems than waste 
  incineration.   I don't believe that and I don't think
  Greenpeace would either.
  
  But here are the assumptions you are making....
  
  The proposition that PVC degrades to vinyl chloride in landfills
  in the absence of both heat and UV and that this 
  would be the principle source of the chlorinated
  content of landfill gas....  I really find that
  hard to accept as being significant at all as 
  a source.   But if you have research showing 
  that is the case rather than shear supposition, 
  please tell us where it can be found.
  
  If chlorinated compounds are
  present in landfill gas I find it much more likely
  that the sources will be PCB materials disposed
  in landfills that evaporate, chlorinated solvents 
  contained in consumer products (i.e. freon, 
  methylene chloride, paint related solvents, etc.), 
  small quantity industrial waste disposal or 
  older surrepticious industrial waste solvent 
  disposal.
  
  Finally, there are a whole range of combustion 
  devices that are used to deal with landfill gas.  There
  are the old style torches, there are dedicated
  gas combustors with burners, there are internal 
  combustion engines use for electricity generation.
  
  If you are quite certain that all three catagories of
  these combustion devices are significant sources
  of PCDD/PCDF emissions, please tell us the 
  source of your information and the amount of 
  PCDD/PCDF generated, and why anyone would
  want to be concerned on a priority basis about
  landfill combustors as a source as opposed to 
  all of the other clearly characterized sources 
  of PCDD/PCDF out there?
  
  
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