Liquid purification or separation – Processes – Treatment by living organism
Reexamination Certificate
2000-01-11
2001-09-04
Upton, Christopher (Department: 1724)
Liquid purification or separation
Processes
Treatment by living organism
C210S610000, C210S620000, C210S632000, C210S747300, C210S760000, C210S170050, C210S209000, C210S920000
Reexamination Certificate
active
06284138
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to treatment of sewage and, more particularly, is concerned with a method and arrangement for introduction of sewage pre-treatment at a site in a municipal sewage treatment system located upstream of a municipal sewage treatment facility of the system.
2. Description of the Prior Art
Municipal sewage (which, as used hereinafter, includes wastewater) collection, conveyance and treatment systems (hereinafter referred to as “sewage treatment systems”) are extensive networks of interconnected pipeline infrastructure. Because of expansiveness and topography of municipal sewage treatment systems, sewage flows cannot always be conveyed by gravity. As a result, pumping sites are needed as part of the pipeline infrastructure to lift sewage flows over high points in the system or to the municipal treatment facilities.
A pumping site may be provided at a collection point of a project such as a housing development, an apartment complex development or a commercial office facility development The pumping site is used to pump untreated sewage collected from the development through a “force main” to a higher point where the untreated sewage can then flow by gravity to the municipal sewage treatment facility to be treated. The pumping site may also be provided at a point in the pipeline infrastructure where gravity flow is no longer able to deliver the untreated sewage to the sewage treatment facility due to the topography. The pumping site typically employs a collection sump receives and accumulates the untreated sewage from the upstream network of piping and a mechanical pump which then pumps the sewage from the collection sump through the force main to a higher point where the untreated sewage can flow by gravity to the sewage treatment facility to be treated. In a typical municipality, the sewage pipeline infrastructure of the sewage treatment system will contain numerous pumping sites to enable the flow of untreated sewage to reach the sewage treatment facility.
Odor control is understood to be the main problem in the sewer pipeline infrastructure of municipal sewage systems. Most odor producing compounds found in sewage result from anaerobic (without air) biological activity which consumes organic material, sulfur, and nitrogen found in the sewage. Organic odors are typically the result of biological activity that decomposes organic matter and forms a variety of malodorous gases.
At municipal sewage treatment facilities, sewage is typically treated using the processes of clarification, aeration and disinfection. The main additives in the treatment process are oxygen or air for biodegradation of the organics in the sewage and electrical power to operate pumps and compressors that deliver and mix the oxygen or air.
Due to expanding residential and commercial development the demands on municipal sewage treatment systems are ever increasing, requiring additional capital investment to meet the demands. However, the resources of municipalities are typically fee and tax based and consumed substantially by expenditures to cover current operating costs and oftentimes are insufficient to finance additional capital investments. Representative examples of various proposals to address this and other needs are those disclosed in U.S. Pat. No. 3,875,051 to Kovarik, U.S. Pat. No. 4,919,814 to Camahan et al., U.S. Pat. No. 5,332,502 to Wickens et al. and U.S. Pat. No. 5,807,484 to Couture et al.
However, none of these proposals appear to offer workable approaches for improvement of municipal sewage treatment systems without significant additional capital investment.
Consequently, a need still exists for innovation in connection with municipal sewage treatment systems which will increase the capacity of such systems with minimal additional capital investment.
SUMMARY OF THE INVENTION
The present invention provides a method and arrangement for introduction of sewage pre-treatment at a site upstream of a municipal sewage treatment facility which are designed to satisfy the aforementioned need. The innovation fostered by the sewage pre-treatment introduction method and arrangement of the present invention is the introduction of a biological activity enhancing agent into the flow of untreated sewage at a preselected site in the pipeline infrastructure of the municipal sewage treatment system located upstream of the sewage treatment facility so that the flow of sewage will be at least partially pre-treated by the time it reaches the sewage treatment facility. The method and arrangement of the present invention, more particularly, utilizes an existing pumping site to provide a convenient location to add the agent to the untreated sewage flow. The agent can be oxygen to convert an anaerobic state to an aerobic state in the sewage flow or ozone to deplete the bacteria content of the sewage flow. The addition of oxygen eliminates hydrogen sulfide (odor) and reduces organic loading of the sewage treatment facility. The biological activity fostered by the oxygen is further enhanced due to temperatures in the sewer pipeline infrastructure ordinarily being greater than at the sewage treatment facility. Higher biological efficiencies are thereby attained. As a result of the method and arrangement of the present invention, capacity of the sewage treatment facility can be significantly increased without a major capital investment.
Accordingly, the present invention is directed to a sewage pre-treatment introduction method which comprises the steps of: (a) selecting a site in a pipeline infrastructure of a sewage treatment system between a source of untreated sewage and a sewage treatment facility of the system; (b) providing a source of a biological activity enhancing agent at the selected site; and (c) introducing the agent from the source thereof into a flow of untreated sewage at the selected site so as to convert the sewage from an untreated state to a pre-treated state in the pipeline infrastructure upstream of the sewage treatment facility.
The present invention also is directed to a sewage pre-treatment introduction arrangement which comprises: (a) a selected site in a sewer pipeline infrastructure of a sewage treatment system between source of untreated sewage and a sewage treatment facility of the sewage treatment system; (b) a source of a biological activity enhancing agent at the selected site; and (c) introducing the agent from the source thereof into a flow of untreated sewage at the selected site so as to convert the sewage from an untreated state to a pre-treated state in the pipeline infrastructure upstream of the sewage treatment facility.
In both the pre-treatment introduction method and arrangement, the agent introduced can be an oxygen-bearing gas for changing the sewage flow from an anaerobic to aerobic state, an ozone-bearing gas for depleting the bacterial content of the sewage flow, or an enzyme for increasing the microbial activity in the sewage flow. The selected site can be a sewage collection site or a pumping site in the pipeline infrastructure. The agent can be introduced by use of an agent generator and a mixing device interposed in the piping of the infrastructure at the selected site which receives the introduced agent from the generator and mixes the agent with the sewage flow at the site. In the case where the selected site is a pumping site, the agent is mixed with the sewage flow either upstream or downstream of a pump at the pumping site.
These and other features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.
REFERENCES:
patent: 1439406 (1922-12-01), Elrod
patent: 1963354 (1934-06-01), Currie
patent: 2788127 (1957-04-01), Davidson
patent: 3335082 (1967-08-01), Ullrich
patent: 3525685 (1970-08-01), Edwards
patent: 3607735 (1971-09-01), Hover
patent: 3734850 (1973-05-01), K
Flanagan John R.
Hydro Flo, Inc.
Swartz Michael R.
Upton Christopher
LandOfFree
Method and arrangement for introduction of sewage... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and arrangement for introduction of sewage..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and arrangement for introduction of sewage... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2449715