SOLIDITECH, INC.

(Solidification and Stabilization)

TECHNOLOGY DESCRIPTION:

This solidification and stabilization process immobilizes contaminants in soils and sludges by binding them in a concrete-like, leach-resistant matrix. Contaminated waste materials are collected, screened to remove oversized material, and introduced to the batch mixer (see figure below). The waste material is then mixed with water; Urrichem, a proprietary chemical reagent; proprietary additives; and pozzolanic material (fly ash), kiln dust, or cement. After it is thoroughly mixed, the treated waste is discharged from the mixer. Treated waste is a solidified mass with significant unconfined compressive strength (UCS), high stability, and a rigid texture similar to that of concrete.

WASTE APPLICABILITY:

This process treats soils and sludges contaminated with organic compounds, metals, inorganic compounds, and oil and grease. Batch mixers of various capacities can treat different volumes of waste.

STATUS:

This technology was accepted into the SITE Demonstration Program in 1988. The solidification and stabilization process was demonstrated in December 1988 at the Imperial Oil Company/Champion Chemical Company Superfund site in Morganville, New Jersey. This site formerly contained both chemical processing and oil reclamation facilities. Soils, filter cakes, and oily wastes from an old storage tank were treated during the demonstration. These wastes were contaminated with petroleum hydrocarbons, polychlorinated biphenyls (PCB), other organic chemicals, and heavy metals. The Technology Evaluation Report (EPA/540/5-89/005a), Applications Analysis Report (EPA/540/A5-89/005), and Demonstration Bulletin (EPA/540/M5-89/005) are available from EPA.

This technology is no longer available through a vendor. Contact the EPA Project Manager for further information.

DEMONSTRATION RESULTS:

Key findings from the Soliditech demonstration are summarized below:

Extract and leachate analyses showed that heavy metals in the untreated waste were immobilized.

• The process solidified both solid and liquid wastes with high organic content (up to 17 percent), as well as oil and grease.
• Volatile organic compounds in the original waste were not detected in the treated waste.
• Physical test results of the solidified waste showed (1) UCS ranging from 390 to 860 pounds per square inch (psi); (2) very little weight loss after 12 cycles of wet and dry and freeze and thaw durability tests; (3) low permeability of the treated waste; and (4) increased density after treatment.
• The solidified waste increased in volume by an average of 22 percent. Because of solidification, the bulk density of the waste material increased by about 35 percent.
• Semivolatile organic compounds (phenols) were detected in the treated waste and the toxicity characteristic leaching procedure (TCLP) extracts from the treated waste, but not in the untreated waste or its TCLP extracts. The presence of these compounds is believed to result from chemical reactions in the waste treatment mixture.
• The oil and grease content of the untreated waste ranged from 2.8 to 17.3 percent (28,000 to 173,000 parts per million [ppm]). The oil and grease content of the TCLP extracts from the solidified waste ranged from 2.4 to 12 ppm.
• The pH of the solidified waste ranged from 11.7 to 12.0. The pH of the untreated waste ranged from 3.4 to 7.9.
• PCBs were not detected in any extracts or leachates from the treated waste.
• Visual observation of solidified waste revealed bulk oily material about 1 millimeter in diameter.

FOR FURTHER INFORMATION:

EPA PROJECT MANAGER:
Jack Hubbard
U.S. EPA
National Risk Management Research Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
513-569-7507
Fax: 513-569-7620