|Chlorinated organic compounds in digested, heat-conditioned, and purifax-treated sludges /
Pincince, Albert B.
| U.S. Environmental Protection Agency, Municipal Environmental Research Laboratory : Center for Environmental Research Information [distributor],
Sewage sludge digestion
|In Binder Received from HQ
|3 pages : illustrations ; 28 cm
Caption title. At head of title: Project summary. "Sept. 1984." Distributed to depository libraries in microfiche. "EPA/600-S2-84-117."
"A study was conducted to investigate the effects of sludge stabilization methods on the production of priority pollutants and chlorinated organics. Three stabilization methods were examined in pilot studies - the Purifax process, anaerobic digestion, and heat conditioning. Results showed that sludge processed by the Purifax process at chlorine dosages normally used in processing wastewater sludges contains 2 to>14 times the total organic chlorine in raw sludge. Both insoluble and soluble forms of organic chlorine increase with chlorine dosage. According to the study, most of the chlorinated compounds are associated with the solid fraction of the sludge. More than 94 percent of the total organic chlorine is insoluble, and about 97 percent of that is associated with the cake. Using the Tchebychev inequality, it was determined that the probability that Purifax treatment produces the same concentration of insoluble organic chlorine in sludge cake as the other stabilization processes is less than 22.5 percent (assuming a unimodal distribution, this probability is less than 10 percent). Leachate obtained by the EPA extraction procedure contained less than 0.2 percent of the organic chlorine in the sludge cake after Purifax treatment. In analyses for priority pollutants, less than 16 percent of the chlorinated material was identified. A new analytical technique using ionization/gas chromatography/mass spectrometry gave results inconsistent with the priority pollutant analyses."