Liquid purification or separation – Processes – Making an insoluble substance or accreting suspended...
Patent
1997-10-20
1999-11-30
Hruskoci, Peter A.
Liquid purification or separation
Processes
Making an insoluble substance or accreting suspended...
210721, 210724, 210726, 210737, 210911, C02F 158
Patent
active
059936673
ABSTRACT:
The present invention provides an efficient and highly effective method of removing dissolved selenium from a variety of refinery process water and wastewater streams. The present invention also provides a new and effective method of oxidizing selenium and organo-selenium compounds to the selenite [+IV] oxidation state in order to be adsorbed by a metal oxide or metal hydroxide precipitate. The invention includes two continuous stirred-tank reactors (CSTR) operated in series. The stream to be treated and one of several iron salts (ferric sulfate, ferric chloride, etc.) are introduced into the first CSTR, forming ferric hydroxide and ferric oxyhydroxide precipitates. The pH of the first CSTR is automatically controlled by adjusting the injection rate of the ferric salt. The effluent stream from the first CSTR is directed into a second CSTR into which potassium permanganate is introduced. The selenium in the original stream to be treated is oxidized to selenite [+IV]; manganese dioxide precipitates as a byproduct of the oxidation reactions. The selenite is then adsorbed by the various precipitates, which are removed by centrifugation. The pH of the centrifuged water is automatically adjusted by the controlled addition of sodium hydroxide. The effectiveness of this continuous process has been demonstrated for streams with a wide range of selenium concentrations, including refinery wastewater and refinery stripped sour water. The process is also effective for treating secondary waste water streams, such as reverse osmosis reject water and ion exchange regeneration wastewater, which result from the pretreatment of refinery wastewater or refinery stripped sour water.
REFERENCES:
patent: 3933635 (1976-01-01), Marchant
patent: 3954603 (1976-05-01), Curtin
patent: 4405464 (1983-09-01), Baldwin et al.
patent: 4519913 (1985-05-01), Baldwin et al.
patent: 4678584 (1987-07-01), Elfline
patent: 4687559 (1987-08-01), Coburn et al.
patent: 4792405 (1988-12-01), Baker
patent: 4806264 (1989-02-01), Murphy
patent: 4853110 (1989-08-01), Singhal et al.
patent: 4915928 (1990-04-01), Marcantonio
patent: 4940549 (1990-07-01), Olsen et al.
patent: 4943377 (1990-07-01), Legare, III
patent: 5071568 (1991-12-01), Bennett et al.
patent: 5164095 (1992-11-01), Sparapany et al.
patent: 5200082 (1993-04-01), Olsen et al.
patent: 5250185 (1993-10-01), Tao et al.
patent: 5264133 (1993-11-01), Forschner et al.
patent: 5322600 (1994-06-01), Spitz et al.
patent: 5376262 (1994-12-01), Perry
patent: 5401420 (1995-03-01), Siefert
patent: 5492620 (1996-02-01), Evans
patent: 5510040 (1996-04-01), Miller et al.
patent: 5575919 (1996-11-01), Santina
"Adsorption of selenuim by amorphus iron oxyhydroxide and manganese dioxide," by Laurie S. Balistrier, et al., Geochimica et Cosmochimica Acta, vol. 54, pp. 739-751.
"Selenium Adsorption by Goethite," by Laurie S. Balistrieri, et al., Soil Science Society of America Journal, vol. 51, No. 5, Sep.-Oct. 1987.
"Optimization of Ferric Hydroxide Coprecipitation Process for Selenium Removal from Petroleum Refinery Stripped Sour Water," by Matthew B. Gerhardt, et al.
"Dirty Crude," (The first oil industry-wide analysis of selenium discharge trends impacting San Francisco Bay) by Citizens for a Better Environment (CBE), Report No. 94-1, Mar. 1994.
Texaco Memorandum from Dr. R. B. Borey to D. R. Hall, "RES-02-03, Selenium Removal From BkP Wastewater" (Report on Bench Scale Study), dated Jul. 10, 1992.
"Removal of Selenium from Refinery Discharges," by Joel Harmon, Shell Martinez, et al., Western States Petroleum Association, dated May 1992.
Memorandum of Western States Petroleum Association from Scott Folwarkow, et al. to Bay Area Refining Committee, re "Approval of Selenium Cease and Desist Order and WSPA Settlement," dated Jan. 19, 1994.
WSPA Selenium Technology Study (Charts).
"Selenium Speciation," Final Report of Western States Petroleum Association, Brown and Caldwell, Jul. 1994.
"Removal of Selenium by Iron-Based Treatment Processes," Final Report of Western States Petroleum Association, Brown and CaldwellI, May 1995.
"Selenium Removal Technology Study," Project Final Report of Western States Petroleum Association, Montgomery Watson, Jul. 1995.
"Removal of Metals From Wastewater" (Neutralization and Precipitation), Chapters 3, 4, 6 and 7. Prepared by A. S. Goldfarb, et al., copyright 1984.
American Water Works Association, Water Quality and Treatment, 4th Ed., McGraw Hill, 1990, Chapters 1, 2, 3, 10 & 12.
Electric Power Research Insitiute, Trace Element Removal by Iron Adsoption/Coprecipistation: Proces Design Manual, No. GS-7005, 1990, pp.: Table of Contents, 1-1 to 1-7, 2-1 to 2-32, 3-1 to 3-12, 4-1 to 4-12, A-1 to A10, and B-1 to B14.
Gibson Henry H.
Hruskoci Peter A.
Texaco Inc.
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