Process for removal of dissolved hydrogen sulfide and reduction of sewage BOD in sewer or other waste systems

a technology of dissolved hydrogen sulfide and sewage bod, which is applied in the direction of biological water/sewage treatment, sustainable biological treatment, multi-stage water/sewage treatment, etc., can solve the problem of instantaneous removal of hydrogen sulfide, and achieve the elimination or substantial reduction of hydrogen sulfide and other minor odors

USRE37181E1Inactive Publication Date: 2001-05-22UNITED STATES FILTER CORPORATION
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Patent Information

Authority / Receiving Office
US · United States
Patent Type
Patents(United States)
Current Assignee / Owner
Publication Date
2001-05-22
Estimated Expiration
Not applicable · inactive patent

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Abstract

Removal of dissolved hydrogen sulfide and a reduction in BOD is achieved by the addition of nitrate ions to waste systems in an amount sufficient to stimulate growth of bacteria which utilize dissolved hydrogen sulfide in their metabolism. Specifically, about 2.4 lbs. <INS-S DATE="20010522" ID="INS-S-00001">nitrate <INS-E ID="INS-S-00001">oxygen per lb. of sulfide is required.
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Description

BACKGROUND AND SUMMARY OF THE INVENTIONThis invention relates to a process for the removal or reduction of dissolved hydrogen sulfide, and reduction of BOD in sewer systems, municipal waste treatment plants and in other industrial waste applications.It is known to add nitrates or nitrites to sewage to effect reduction in BOD and even to suppress the formation of hydrogen sulfide gas via bacterial action. See, for example, U.S. Pat. Nos. 3,300,404; 4,446,031; and 4,681,687.It is also known to add nitrates to sewage in order to control objectionable odors. See, for example, U.S. Pat. Nos. 3,966,450; 4,108,771.There have also been attempts to remove hydrogen sulfide directly from waste. For example, in U.S. Pat. No. 4,680,127, the patentee adds amounts of glyoxal, or glyoxal in combination with formaldehyde or glutaraldehyde, in order to reduce or scavenge the amount of hydrogen sulfide in aqueous or wet gaseous mediums.In U.S. Pat. No. 4,501,668, the patentee utilizes polycondensation...

Examples

example

With reference to the FIGURE, sodium nitrate was added to a sewer system in Jacksonville, Florida at a master pump station, or feed point B, upstream of a second master pump station comprising a monitoring point A. The feed point B was at a point removed from an intersection C of the feed line and main sewage line, as indicated in the FIGURE.

The treated sewage continued to a downstream waste water treatment plant in Jacksonville, indicated as point D.

Average detention times (based on average daily flows, line sizes and lengths are as follows:

B.fwdarw.C 7 hours

C.fwdarw.A 3.3 hours

B.fwdarw.A 10.3 hours

In terms of the description provided above, the B.fwdarw.C distance and retention time of 7 hours constitutes the incubation period, coupled with the distance C.fwdarw.A and associated retention time of 3.3 hours comprises a total of 10.3 hours from addition of the nitrate station at point B to the monitoring at point A, thereby permitting sufficient time for the bacteria to culture.

The ...