Applicability Limitations

Chemical hydrolysis applies to a wide range of otherwise refractory organics. Hydrolysis is used to detoxify waste streams of carbamates, organophosphorous compounds and other pesticides. Acid hydrolysis as an in-situ treatment must be performed carefully due to potential mobilization of heavy metals. In addition, depending on the waste stream, products may be unpredictable and the mass of toxic discharge may be greater than the waste originally input for treatment.

Status. Common industrial process. CHEMICAL OXIDATION

Oxidation destroys hazardous contaminants by chemically converting them to nonhazardous or less toxic compounds that are stable, less mobile, or inert. Common oxidizing agents are ozone, hydrogen peroxide, hypochlorites, chlorine, and chlorine dioxide. Current research shows that combining these reagents, or combining ultraviolet (UV) light and oxidizing agent(s) makes the process more effective.

The effectiveness of chemical oxidation on general contaminant groups is shown in Table 11.15.6 (U.S. EPA 1991). Chemical oxidation depends on the chemistry of the oxidizing agents and the chemical contaminants. Table 11.15.7 lists selected organic compounds by relative oxidization ability. The oxidation process is nonselective; any oxidizable material reacts. Chemical oxidation is also a part of the treatment process for cyanide-bearing wastes and metals such as arsenic, iron, and manganese. Metal oxides formed in the oxidation process precipitate more readily out of the solution.

Some compounds require a combination of oxidizing agents or the use of UV light with an oxidizing agent.

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