Comparison of two methods for the solidification of oily pond sludges

Sludge samples from two waste impoundments containing high concentrations of heavy oils (>25%) were subjected to two different laboratory solidification testing regimes. It was found that less cement was needed for solidification on an equivalent compressive strength basis for test samples to which soils were added from a dry evaporation pond than for those samples to which soil was not added. In addition, air-drying and physical compaction of samples into molds was found to increase ultimate sample compressive strengths. Procedures which include addition of dirt, compaction, and air-drying could decrease all-over solidification costs and increase the quality of solidified oily sludges.