Test Criterion for Stabilization

Based on toxicological studies, the US Environmental Protection Agency (EPA) has determined that, in addition to a large number of organic chemicals, the following metals are hazardous and need effective stabilization prior to disposal  

These metals are considered hazardous under the Resource Recovery and Conservation Act of 1987 (RCRA) [4]. The RCRA metals occur in chemical forms that are soluble or insoluble in groundwater. The soluble species are of concern from the dispersibility viewpoint. Hence, the test criterion to evaluate whether a given waste stream needs stabilization prior to disposal is based on how much a given hazardous metal dissolves in water in a standardized test. This EPA test, called the Toxicity Characteristic Leaching Procedure (TCLP) [5], is used not only to identify which waste streams need treatment, but also to assess whether the treated waste form is suitable for disposal. This test also sets limits on how little of a hazardous metal is permitted to leach out from a given waste to pass the waste for disposal. If the test determines that the waste is not suitable for safe 

Chapter 16 Applications of CBPCs to Hazardous Waste Stabilization 

This test is the key to success of any stabilization method for treatment of hazardous waste. Because the waste is crushed and leached using acidic water, the actual leaching of the contaminants depends on their solubility. Thus, as in the case of CBPC formation discussed in Chapters 4-6, solution chemistry plays a major role in stabilization. For this reason, we review the solution chemistry of the hazardous contaminants before we proceed to the actual stabilization. 

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