Disposal, reaction hazard evaluation

Leo Weitzman received his Ph.D. in chemical engineering from Purdue University. He is a consultant with 29 years of experience in the development, design, permitting, and operation of equipment and facilities for treating hazardous waste and remediation debris. Dr. Weitzman has extensive experience in the disposal of hazardous waste and contaminated materials by thermal treatment, chemical reaction, solvent extraction, biological treatment, and stabilization. He has published more than 40 technical papers. Dr. Weitzman is currently serving on the National Research Council s Committee on Review and Evaluation of Alternative Technologies for Demilitarization of Assembled Chemical Weapons Phase 2. 

Any hazard evaluation must thus include an examination of all phases of the process. As with the example above, one area which is often ignored involves the quenching, scrubbing, and disposal of reactions. It must be remembered that these reactions suffer the same consequences of scale-up as the more productive components of the process. 

Diehlorobenzidine has been identified in at least 32 of the 1,467 current or former EPA National Priorities List (NPL) hazardous wastes sites (HazDat 1998). However, the number of sites evaluated for 3,3 -diehlorobenzidine is not known. The frequeney of these sites within the United States can be seen in Figure 5-1. The manufacture and use of 3,3 -dichlorobenzidine has been strictly regulated by OSHA since 1974. All work with the compound is done in elosed systems and any residues are destroyed by chemical reaction. Such precautions, if conscientiously praetieed, make it unlikely that significant quantities of 3,3 -diehlorobenzidine have been disposed of in landfills or at NPL sites after 1974. 

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