Lime stabilization of primary sludges.

Abstract

that the extended test planned would over load the existing digester and the new kinds of sludge would possibly cause di gester problems. Consequently, the Ulti mate Disposal Research Program staff at the Taft Laboratory was asked to recom mend and operate a suitable sludge dis posal system during the testing period. The requirements of the project for a disposal system that could be installed quickly with minimum capital cost, would be easy to operate, and would produce a safe and stable product did not allow a choice of numerous options. Chemical treatment was chosen to meet these re quirements. Lime represented the cheap est and safest chemical that could produce a stable, pathogen-free sludge. Preliminary studies conducted on sludges supplied by the pilot plant indicated that costs of lime treatment would be low, pathogens and odor greatly reduced, and filterability improved. These findings led to lime treatment of sludge on a plant scale during the alum and iron addition experi ments and to documentation of the results.