Liquid purification or separation – Processes – Treatment by living organism
Reexamination Certificate
1998-10-16
2001-09-11
Barry, Chester T. (Department: 1724)
Liquid purification or separation
Processes
Treatment by living organism
C210S617000, C210S629000, C210S631000, C210S121000, C210S151000, C210S202000, C210S263000, C210S290000, C210S748080, C210S754000
Reexamination Certificate
active
06287469
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods and equipment for tertiary sewage treatment by naturally-occurring microorganisms after the sewage has passed from a septic tank or other primary treatment device.
2. Description of the Prior Art
Various sewage treatment systems are known for treating the waste stream from small communities, housing developments and single family units. With the establishment of state and federal guidelines, the need has become more acute for a system to handle sewage disposal needs where traditional methods do not work.
Septic tanks are the most commonly used means of treating sewage from a single source. They employ anaerobic bacteria for the primary decomposition of sewage, separating some solid wastes from liquid. The liquid waste streams from septic tanks are often discharged directly to the entry of a subsurface drain field. The remainder of wastewater treatment occurs in the soil. However, many sites and many soil types are unable to accomplish this process in a manner that meets applicable guidelines.
Tertiary treatment systems employ processes in which anaerobic decomposition is followed by aerobic decomposition. Tertiary systems lessen the burden on the land, as soils are no longer being called upon to treat wastewater.
A secondary treatment method wherein aerobic processes are augmented, for example, by a flow of gas through the material to be treated, is known from U.S. Pat. No. 3,202,285. It has also been proposed to use a gravel bed in secondary treatment, as set forth in U.S. Pat. Nos. 3,057,796 and 4,293,421.
U.S. Pat. No. 5,597,477 contains a description of a sewage effluent disposal system comprising a primary sewage treatment tank and an effluent holding tank. A float switch controls the pumping of effluent from the effluent holding tank. Secondary treatment is accomplished by passing the effluent through a sparger as it enters the secondary treatment tank, or by adding disinfectant as the effluent passes through the sparger. The secondary treatment tank does not contain a filtration bed.
It is an object of the present invention to provide a wastewater treatment system in which tertiary treatment occurs in enclosed, controlled conditions rather than in surrounding soils, so that the invention can be used where soils are marginal or cannot be used with other systems.
The tertiary treatment recirculation process may be controlled by a timer and a pump float responding to the wastewater level in the recirculation tank, thus providing an automated control system.
Another object of the invention is to provide a wastewater treatment system as described in the preceding paragraphs in which the effluent is safe and environmentally acceptable. Yet another object of the invention is to provide a durable wastewater treatment system, requiring minimal maintenance, and in which repair and regeneration are readily accomplished.
SUMMARY OF THE INVENTION
Accordingly, I have invented a system for the tertiary treatment of sewage, comprising a septic tank, which catches the solid component of sewage and houses the primary step of the wastewater treatment process. The heavy solids settle to the bottom of the tank, and the lighter solid material floats to the top. Both solid components largely decompose into liquids and gases in the anaerobic conditions present in the primary treatment step. Relatively clear effluent from the middle level of the septic tank flows into a bottom mixing zone of a recirculation tank. A pump moves effluent from the bottom zone to the top zone of the recirculation tank, where it is distributed over a sand filter located in the top zone, for example, by a spray grid. The effluent trickles through the filter medium where it is treated aerobically and anaerobically by naturally occurring microorganisms. The treated effluent is stored in the bottom zone where it is mixed with incoming septic tank effluent. The effluent is discharged either by gravity or a small discharge pump after which it may be subjected to disinfection.
A complete understanding of the invention will be obtained from the following description when taken in connection with the accompanying drawing figures wherein like reference characters identified like parts throughout.
REFERENCES:
patent: 2987186 (1961-06-01), Burgoon et al.
patent: 3057796 (1962-10-01), Davis
patent: 3202285 (1965-08-01), Williams
patent: 3717251 (1973-02-01), Hampton
patent: 3731812 (1973-05-01), Stone
patent: 3789986 (1974-02-01), Oldham et al.
patent: 4293421 (1981-10-01), Green
patent: 4822485 (1989-04-01), Mayer
patent: 4895645 (1990-01-01), Zorich, Jr.
patent: 4925552 (1990-05-01), Bateson et al.
patent: 5049265 (1991-09-01), Boyd et al.
patent: 5076929 (1991-12-01), Fuchs et al.
patent: 5156742 (1992-10-01), Struewing
patent: 5352357 (1994-10-01), Perry
patent: 5486291 (1996-01-01), Todd et al.
patent: 5534141 (1996-07-01), McAnaney et al.
patent: 5597477 (1997-01-01), Harry, III
patent: 5645725 (1997-07-01), Zitzelsberger et al.
patent: 5667689 (1997-09-01), Graves
patent: 5676828 (1997-10-01), Kallenbach et al.
patent: 2073165 (1980-03-01), None
patent: 2077712 (1980-06-01), None
patent: 62-114699 (1987-05-01), None
patent: 1-124192 (1989-10-01), None
Ashburn, Paul, Recycling Wastewater Reactor, RFS II, 1991.
Ashburn, Paul, Wastewater Treatment Plant, RFS II, 1991.
Ashburn Paul R.
Cogar Edward T.
Ashco-A-Corporation
Barry Chester T.
Prince Fred
Webb Ziesenheim & Logsdon Orkin & Hanson, P.C.
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