Asphalt Encapsulation of Electroplating Waste Using the WPC-VRS Fixation Process

Abstract

The effectiveness of asphalt encapsulation as a method of preventing metal from leaching out of electroplating wastes was assessed by comparing the amounts of metals which leached out of encapsulated and unencapsulated wastes. Two real wastes from an Army depot and two synthetic wastes were encapsulated with asphalt using Werner and Pfleiderer Corporation's volume reduction and solidification process. A portion of each waste was not encapsulated. The encapsulated and unencapsulated wastes were then leached using a modification of the Wisconsin Test, under conditions which simulated those which might occur in a landfill, and the quantities of metals which leached out of each waste were compared. After the leaching tests, the encapsulated, synthetic wastes were found to have lost 1.1 to 1.3% of their original metal content; metal concentrations in the leachates were within the limits proposed by Pennsylvania and the United States Environmental Protection Agency. However, the encapsulated Army depot wastes lost 6 to 20% of their metals and the metal concentrations in the leachate exceeded the proposed limits. Werner and Pfleiderer Corporation's process might be useful in preparing small batches of electroplating waste for disposal. However, the waste would need to be treated prior to encapsulation in order to bind the metals more effectively. Further research needs are discussed.