US 7,479,259 B2Granted

System for destroying hazardous waste resultant from the production of energetics such as explosives

AssigneeThe United States of America as represented by the Secretary of the Army

InventorsByung J. Kim, Seok-Young Oh, Pei C. Chiu, Daniel K. Cha

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Abstract

A waste stream from energetics processing is treated using a pre-filter having media, preferably sand, and a metal that has a reducing potential, preferably elemental iron (Fe0). The pre-filter is connected to a zero-valent metal column reactor. The waste stream is pumped through the pre-filter to trap solids and deoxygenate it, then enters the reactor and is subjected to a reducing process. Fe0 from the reactor is transformed to the ferrous ion (Fe+2), added to the resultant product, and fed to a continuously stirred tank reactor (CSTR) in which Fenton oxidation occurs. This product is then sent to a sedimentation tank and pH-neutralized using a strong base such as sodium hydroxide (NaOH). The aqueous portion is drawn off and the sludge pumped from the sedimentation tank. Both tanks are monitored and controlled to optimize required additives, while monitoring of pressure drop across the pre-filter and column reactor establishes replacement requirements.

Claims20

Dependent claims

A system for converting a waste stream resultant from manufacturing energetics, in particular explosives, said waste stream containing suspended and colloidal solids, comprising:

at least one zero-valent column reactor comprising:
at least one pre-filter containing a zero-valent metal and filter media for removing at least some of said solids from said waste stream,
at least one zero-valent metal contained in said reactor above said pre-filter.
wherein said pre-filter physically removes at least some of said solids, each said pre-filter positioned as the bottom portion of each said column reactor, and
wherein said column reactor establishes a reducing environment in a portion of each said column reactor contiguous with and vertically above said pre-filter, said reducing environment removing oxygen using said zero-valent metal as a reducing agent, and
wherein at least some of said zero-valent metal is provided as a metal ion, and
wherein after said waste stream is treated in said zero-valent column reactor, a first treated waste stream is output;
at least one first vessel in which initial contents include at least an oxidizer to be combined with said first treated waste stream,
wherein said contents of said first vessel are adjusted to optimize the amount of said oxidizer and a metal ion added thereto, said metal ion resultant from processing said waste stream with said zero-valent metal in said zero-valent metal column reactor, and
wherein said contents of said first vessel are further adjusted to optimize the pH of said contents of said first vessel, and
wherein said contents of said first vessel are continuously stirred as part of treating said contents prior to output of said contents as a second treated waste stream;
and
at least one second vessel for accepting said second treated waste stream as at least part of the contents of said second vessel,
wherein the pH of said second treated waste stream is adjusted in said second vessel, and
wherein said contents of said second vessel are further adjusted to optimize pH of said contents of said second vessel, and
wherein said second treated waste stream is permitted to settle prior to drawing off at least one final product for recycling.

13 more elements

A system for converting a waste stream resultant from manufacturing energetics, in particular explosives, said waste stream also containing suspended and colloidal solids, comprising:

at least one means for pre-filtering, said means for pre-filtering containing a zero-valent metal and media for removing at least some of said solids from said waste stream to yield a filtered waste stream;
at least one means for reacting a zero-valent metal with said pre-treated waste stream, said means for reacting a zero-valent metal with said pre-treated waste stream in operable communication with said means for pre-filtering,
wherein after said pre-treated waste stream is treated in said means for reacting a zero-valent metal with said pre-treated waste stream, a first treated waste stream incorporating at least one type of metal ion is output;
at least one means for combining said first treated waste stream with at least an oxidizer,
wherein said combination of said oxidizer and said first treated waste stream is adjusted to optimize the amount of said oxidizer and said metal ion, at least some said metal ion resultant from processing in said means for reacting a zero-valent metal with said pre-treated waste stream, and
wherein said contents of said means for combining said first treated waste stream with at least an oxidizer are further adjusted to optimize the pH of said contents of said means for combining said first treated waste stream with at least an oxidizer, and
wherein said contents of said means for combining said first treated waste stream with at least an oxidizer are stirred as part of processing said contents of said means for combining prior to output of said contents of said means for combining as a second treated waste stream;
and
at least one means for accepting said second treated waste stream as at least part of the contents of said means for accepting said second treated waste stream,
wherein said contents of said means for accepting said second treated waste stream are further adjusted to optimize pH of said contents of said means for accepting said second treated waste stream, and
wherein said second treated waste stream is permitted to settle in said means for accepting said second treated waste stream prior to drawing off at least one final product for recycling.

8 more elements

Dependencies are inferred from the claim text.