Treatment of reducible halohydrocarbon containing aqueous stream
AssigneeEnvirogenics Systems Company
InventorKeith H. Sweeny
Life of this patent
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Abstract
A new, economical system for removal of persistent reducible organic compounds from aqueous streams by passing the stream, preferably at or near neutral pH, into a bottom inlet to a column to provide fluidization of metal reductant catalyzed to provide efficient and economical reduction or dechlorination of a variety of pesticides and other compounds such as PCB or chloroform. The system is especially useful to reduce the level of soluble, reducible hydrocarbons in very dilute waste streams (1 ppm or less) generally by 99% or more.
Claims16
A method of treatment of aqueous streams containing below 100 ppm of reducible organic compounds selected from soluble halogenated, nitrogen containing or hydroxyl containing organic compounds to produce an effluent stream containing at least 90% less of the compounds and a low level of metal ions comprising the steps of:
- adjusting the pH of the stream to between 6 and 8;
- flowing the pH adjusted stream upwardly through a column containing particles of elemental metal reductant capable of reduction of said organic compounds and expanding said particles to at least twice their unsuspended volume to form a fluidized bed of said particles said reductant consisting essentially of a first metal selected from iron, aluminum, zinc, magnesium or cadmium and 0.1 to 10 meq per gram of reductant of at least one catalytic metal selected from copper, silver, cobalt or nickel;
- reductively reacting the compounds with the reductant to produce said effluent stream;
- and
- removing the effluent stream from the bed.
A system for treatment of aqueous streams containing below 100 ppm of reducible organic compounds to produce an effluent stream containing at least 90% less of the compounds and a low level of metal ions comprising:
- a source of said stream;
- pH control means for controlling the pH of said stream to a selected pH between 6 and 8;
- a column having a bottom inlet for receiving a flow of said stream and an outlet for removing said effluent;
- flow means connecting said source to said inlet for flowing said stream upwardly through said column;
- and
- a bed of elemental metal reductant particles capable of reductive degradation reaction with said organic compounds to form an effluent leaving said outlet containing a significantly reduced level of compound, said metal reductant consisting of a first metal selected from iron, aluminum, zinc, magnesium or cadmium and 0.1 to 10 meq per gram of reductant of at least one catalytic metal selected from copper, silver, cobalt or nickel, said bed being constrained within said column between said inlet and outlet whereby on upward flow of said stream a fluidized bed of said particles is formed for reductive degradation of said compound.
Dependencies are inferred from the claim text.