US 4,632,758 AGranted

Anaerobic wastewater treatment system

AssigneeCommonwealth Engineering & Technology, Inc.

InventorThomas E. Whittle

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Abstract

An anaerobic apparatus for treating wastewater is disclosed. The treating apparatus comprises a reactor housing a media having a plurality of surfaces for receiving bacteria. The wastewater that is to be treated, is introduced into the bottom of the reactor and forced up over the surfaces of the media, whereby the bacteria on the surfaces of and in the voids of the media consume the organic materials in the wastewater by an anaerobic digestion process to produce methane and a biological sludge. The biological sludge is collected and stored in a bottom storage portion of the reactor, whereby further digestion occurs to condense the mass of such sludge. A first conduit array is disposed above the media for withdrawing the treated wastewater. A second conduit array is disposed in communication with the storage portion for withdrawing biological sludge from the reactor. bs

Claims13

Dependent claims

Anaerobic apparatus for treating wastewater, said apparatus comprising:

(a) a reactor for receiving and treating the wastewater in an anaerobic process, said reactor having a bottom and a top;
(b) media disposed within said reactor having a plurality of surfaces for receiving bacteria, which consume the waste in the wastewater by an anaerobic digestion process to produce methane and a biological sludge;
(c) storage means disposed in said bottom for storing biological sludge;
(d) first means for introducing the wastewater into said reactor at a point intermediate said media and said bottom, whereby the wastewater is forced up and over said surfaces of said media and into contact with the bacteria;
(e) second means disposed at a point intermediate said top and said media for withdrawing the treated wastewater;
(f) settling means coupled to said second means for receiving the treated wastewater and for permitting settlement of the biological sludge to a bottom thereof, said bottom coupled by a conduit to introduce the biological sludge into said storage means, whereby the population of the methane gas producing bacteria within said reactor is increased and the efficiency of the anaerobic digestion process within said reactor to produce methane is improved;
(g) degassing means coupled to said second means to receive and degas the reactor effluent and is coupled to said settling means to supply degassed reactor effluent thereto, whereby the efficiency of the biological sludge settlement within said settling means is improved;
(h) third means disposed in communication with said storage means for withdrawing the biological sludge from said reactor;
and
(i) means disposed at said top for collecting the methane.

7 more elements

The method of operating an anaerobic apparatus comprising:

(a) a reactor for receiving and treating wastewater in an anaerobic process, said reactor having a bottom and a top;
(b) a medium disposed within said reactor having a plurality of surfaces for receiving bacteria, which consume the waste in the wastewater by an anaerobic digestion process to produce methane and biological sludge;
and
(c) storage means disposed in said bottom for storing biological sludge, the method comprising the step of:
1. heating the wastewater to a temperature of 85.degree. to 100.degree. F.;
2. thereafter, introducing the heated wastewater into said reactor at a point intermediate said media and said storage means;
3. directing the wastewater up and over said surfaces of said media and into contact with the bacteria to produce methane in accordance with the anaerobic digestion process;
4. withdrawing the wastewater after a hydraulic detection time at a point intermediate said top and said media;
5. treating the withdrawn wastewater from the reactor to remove gas therefrom, to enhance the settlement of the biological sludge substantially unimpeded by the presence of gas in the reactor effluent;
6. permitting sludge to settle from the withdrawn wastewater;
and
7. introducing a selective amount of the settled sludge into and storing the sludge in said storage means of said reactor for a solids retention time in excess of said hydraulic detection time, whereby the population of the methane gas producing bacteria within said reactor is increased and the efficiency of the anaerobic digestion precess to produce methane is enhanced.

9 more elements

Dependencies are inferred from the claim text.