Potentially applicable thermal treatment technologies include thermal desorption, pyrolysis, and thermal oxidation. On occasion, vitrification may be warranted to stabilize nonvolatile metals or radionuclides that remain in the ash or residue from other waste treatment processes. Many factors, including the site cleanup criteria, the contaminant types and concentrations, and the chemical and physical characteristics of the material, impact the selection of an effective contaminant elimination or stabilization technology of the contaminated material.

Hazen can design and perform hazardous waste treatability studies for most applications. Our experience includes thermal treatment of soils, sediments, and sludges containing pesticides, polychlorinated biphenyls (PCBs), dioxins and furans, petroleum fuels, and a number of other organic contaminants. We have also successfully treated samples containing inorganic contaminants such as arsenic, lead, mercury, and low-level radionuclides. All treatability studies are performed in compliance with the terms and conditions stipulated by our federal and state approvals and licenses.

Occasionally, processes can be devised to recover or use valuable materials while dealing with hazardous waste components. When possible, recycling presents an attractive alternative to waste destruction. As a result of completing numerous recycling projects, Hazen has developed substantial expertise in recognizing ways to restore certain waste components to marketable forms.

Recent waste treatment and recycling activities include:

• Waste vitrification in a rotary kiln
• Thermal desorption of volatile metals and volatile and semivolatile organic compounds
• Pyrolysis of automobile shredder residue
• Smelting of spent automobile catalyst
• Recovery of tin from bronze scrap
• Thermal oxidation of spent catalyst
• Pyrolysis of nylon-6 to recover its monomer
• Injection smelting of electronic scrap