Treatment of reducible hydrocarbon 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 persistant reducible organic compounds from aqueous streams by passing the stream, preferably at or near neutral pH, through a column containing a 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.
Claims19
A method of treatment of an aqueous stream containing below 100 ppm of reducible organic compounds selected from halogenated organic compounds, nitrogen containing organic compounds or hydroxyl containing organic compounds to produce an effluent stream containing 90% less of the compounds than the aqueous stream and containing a low level of metal ions comprising the steps of:
- adjusting the pH of the stream to between 6 and 8;
- flowing the stream through a permeable bed comprising 5 to 40% by weight of particulate, elemental metal reductant capable of reduction of said organic compounds, the remainder of said bed being finely divided, inert filter and the ratio of reductant to compound within said bed is at least 1000:1 and said metal reductant consisting of essentially 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 less than 100 ppm of reducible organic compounds selected from halogenated organic compounds, nitrogen containing organic compounds or hydroxyl containing organic compounds to produce an effluent stream containing a significantly lower level of the compounds and a low level of metal ions comprising:
- a source of said stream;
- a column having an 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 through said column;
- said flow means including pH control means for controlling the pH of said stream to a selected pH between 6 and 8;
- and
- a permeable bed comprising 5% to 40% by weight of particulate, elemental metal reductant capable of reductive reaction with said organic compounds and the remainder of said bed being finely divided, inert filler, 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 cataytic metal selected from copper, silver, cobalt or nickel, said bed being constrained within said column between said inlet and outlet in which the ratio of reductant to compound is at least 1000:1 for reductive degradation of said compound to form an effluent leaving said outlet containing a significantly reduced level of compound.
Dependencies are inferred from the claim text.