US 4,758,344 AGranted

Method for treating organic garbage, especially household refuse

AssigneeMesserschmitt-Boelkow-Blohm GmbH

InventorFranz X. Wildenauer

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Abstract

Organic waste, especially organic household garbage, is leached in a leaching apparatus for washing out any water soluble organic substances and water soluble heavy metal salts. Air is supplied into the apparatus during the leaching for aerobically decomposing or rotting the organic substances. Non-soluble substances are discharged from the leaching apparatus for further treatment. A liquid flow-off component containing solved substances is withdrawn from the leaching apparatus, collected in an intermediate tank and introduced into an anaerobic solid bed reactor wherein anaerobic bacteria reduce or decompose the liquid flow-off component to form bio-gas which is withdrawn from the solid bed reactor for use or storage in a low pressure tank. The heavy metal salts are precipitated into water non-soluble sulfides and the flow-off is returned for further leaching to the leaching apparatus in a substantially closed circuit in which any lost leaching liquid is replenished.

Claims9

Dependent claims

A method for treating organic waste material normally including heavy metal salts, comprising the following steps:

(a) introducing the organic waste material into a leaching device,
(b) uniformly distributing the organic waste material within the leaching device,
(c) leaching said organic material by a leaching liquid including primarily water in said leaching device for washing soluble substances including heavy metal salts out of said organic waste material to provide a liquid flow-off component comprising said soluble substances including said heavy metal salts in solution,
(d) aerobic rotting of the organic material by introducing air into said leaching device during said leaching step,
(e) removal of non-soluble substances from the leaching device for further treatment,
(f) withdrawal of said liquid flow-off component containing solved substances, from the leaching device,
(g) collecting, in an intermediate tank, said liquid flow-off component containing said solved substances,
(h) withdrawing said liquid flow-off component from said intermediate tank as needed,
(i) introducing said liquid flow-off component into an anaerobic solid bed reactor,
(j) reducing said solved organic substances in said solid bed reactor, into a bio-gas containing methane gas and carbon dioxide by subjecting said solved organic substances in said solid bed reactor to the action of anaerobic bacteria,
(k) precipitating said heavy metal salts by a reaction for forming non-soluble heavy metal sulfides,
(l) returning a liquid overflow from said solid bed reactor to said leaching device for supplying said leaching liquid to said leaching device for irrigating said organic waste material in a leaching circuit, and
(m) withdrawing said bio-gas from said solid bed reactor for further use.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/942,265Filed 17 Dec 1986
Priority: DE 354567921 Dec 1985
Granted: 19 Jul 1988
Term ends: Not estimatedThe source records don’t support an estimate.

Classification23 codes

C05F 17/986
For feeding or discharging materials to be treated; for feeding or discharging other material: the other material being liquid
B03B 9/06
General arrangement of separating plant, e.g. flow sheets: specially adapted for refuse
B09B 3/35
Involving mechanical treatment: shredding, crushing or cutting
B09B 3/60
Destroying solid waste or transforming solid waste into something useful or harmless: biochemical treatment, e.g. by using enzymes