Browse Prior Art Database

SELENIUM WASTE WATER REMEDIATION

IP.com Disclosure Number: IPCOM000026823D
Original Publication Date: 1993-Oct-31
Included in the Prior Art Database: 2004-Apr-06
Document File: 2 page(s) / 121K

Publishing Venue

Xerox Disclosure Journal

Abstract

Disclosed is a process for remediation of selenium containing waste streams. The process uses magnesium salts, for example, magnesium chloride or magnesium sulfate to precipitate selenium containing ions out of aqueous process streams.

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XEROX DISCLOSURE JOURNAL

pHJ MgCk

7.5

8.5

SELENIUM WASTE WATER REMEDIATION
Donald J. Goodman Lawrence Kotowicz
Timothy J. Leenhouts Donald P. Sullivan
Joseph R. Weber

Proposed Classification
U.S. C1.430/059 Int. C1. G03g 05/06

Disclosed is a process for remediation of selenium containing waste streams. The process uses magnesium salts, for example, magnesium chloride or magnesium sulfate to precipitate selenium containing ions out of aqueous process streams.

Selenium in certain process streams is in the form of soluble sodium selenite. Precipitation with magnesium salts provides magnesium selenite. Magnesium selenite recovered therefrom may be used in the glass industry to remove green color tint from glass. An efficient extension of this procedure is, for example, to follow a magnesium sulfate precipitation with a calcium chloride induced precipitation step. The insoluble calcium sulfate formed will coprecipitate additional magnesium selenite thus reducing the selenium concentration even further. The remaining remediated water, which makes up most of the weight, is then pH adjusted to neutrality and discharged. The optimum pH for sodium selenite precipitation is between 10 and 10.5.

395 mg/L 151 mg/L 132 mg/L

363 mg/L 120 mg/L 93 mg/L

840 mg/L 121 mg/L 102 mg/L 1930 mg/L 1870 mg/L 1730 mg/L

XEROX DISCLOSURE JOURNAL - Vo1.18,No. 5 SeptembedOctober 1993 567

An experiment where the pH of the solution and the concentration of added MgC12 was varied, and the precipitate (if one formed) separated by centrifugation. Samples were analyzed by atomic absorption for soluble selenium remaining after centrifugation in the clear supernatant liquid, and are listed in the table below.

11.5

ca. 13

1 mL 3 mL 5 mL

2030 mg/L 2020 mg/L 1970 mg/L 2040 mg/L 1610 mg/L 232 mg/L

9.5

10.5

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SELEN...