GB2199820A - Treatment of waste material - Google Patents
Treatment of waste material Download PDFInfo
- Publication number
- GB2199820A GB2199820A GB8628174A GB8628174A GB2199820A GB 2199820 A GB2199820 A GB 2199820A GB 8628174 A GB8628174 A GB 8628174A GB 8628174 A GB8628174 A GB 8628174A GB 2199820 A GB2199820 A GB 2199820A
- Authority
- GB
- United Kingdom
- Prior art keywords
- oxygen
- pile
- temperature
- enriched air
- composting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002699 waste material Substances 0.000 title description 4
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 38
- 239000001301 oxygen Substances 0.000 claims abstract description 38
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims abstract description 33
- 238000009264 composting Methods 0.000 claims abstract description 20
- 239000007787 solid Substances 0.000 claims abstract description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract 11
- 238000000034 method Methods 0.000 claims description 21
- 239000000203 mixture Substances 0.000 claims description 7
- 239000007789 gas Substances 0.000 claims description 6
- 239000002023 wood Substances 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 3
- 239000003415 peat Substances 0.000 claims description 3
- 239000010801 sewage sludge Substances 0.000 claims description 3
- 239000010902 straw Substances 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 2
- 239000002002 slurry Substances 0.000 claims description 2
- 238000005065 mining Methods 0.000 claims 1
- 235000013311 vegetables Nutrition 0.000 claims 1
- 239000010802 sludge Substances 0.000 description 13
- 241000894006 Bacteria Species 0.000 description 5
- 239000002361 compost Substances 0.000 description 5
- 238000009826 distribution Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 230000029087 digestion Effects 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical class O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000005273 aeration Methods 0.000 description 1
- 241001148470 aerobic bacillus Species 0.000 description 1
- 238000005842 biochemical reaction Methods 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- UBAZGMLMVVQSCD-UHFFFAOYSA-N carbon dioxide;molecular oxygen Chemical compound O=O.O=C=O UBAZGMLMVVQSCD-UHFFFAOYSA-N 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05F—ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE
- C05F17/00—Preparation of fertilisers characterised by biological or biochemical treatment steps, e.g. composting or fermentation
- C05F17/70—Controlling the treatment in response to process parameters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/141—Feedstock
- Y02P20/145—Feedstock the feedstock being materials of biological origin
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/40—Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Biotechnology (AREA)
- Health & Medical Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Microbiology (AREA)
- Molecular Biology (AREA)
- Organic Chemistry (AREA)
- Fertilizers (AREA)
- Treatment Of Sludge (AREA)
Abstract
In compositing organic solids, a pile of the solids is formed, pure oxygen or oxygen-enriched air is passed into the pile, the temperature internally of the pile is monitored, and upon a monitored temperature of the pile reaching a chosen value, air is substituted for the oxygen or oxygen-enriched air. Relatively rapid attainment from cold of an adequate composting temperature is thus made possible. <IMAGE>
Description
TREATMENT OF WASTE MATERIAL
DESCRIPTION
This invention relates to the treatment of waste material. In particular it relates to a method of composting. In the so-called activated sludge process for treating sewage, there is created surplus sludge which is separated from the process and which is unfit for immediate disposal onto the land or into waterways. It is conventional practice to digest this sludge anaerobically. There are two main disadvantages to anaerobic digestion. First, it is a relatively slow process. Second, it requires the installation of large insulated tanks or other vessels in which the sludge can be effectively digested. It has been proposed to perform aerobic sludge digestion, but this process again requires large lagoons or other vessels and difficulties can arise in maintaining a suitable elevated temperature for treatment.
One alternative to sludge digestion is to compost the sludge. Various different methods have been proposed for composting sludge.
Typically, these methods involve reducing the water content of the sludge by conventional means (e.g. pressing), and then mixing with bulking materials such as wood chips, straw or peat. The mixture may be composted in vessels, but this is not a preferred method owing to the capital expense involved. Instead, it is preferably formed into piles which are composted. Typically, the composting is performed in two stages. First, there is a primary composting stage in which the piles are aerated so as to enable aerobic bacteria in the mixture to help break-down relatively easily biodegradable organic compounds in the sludge. The thus formed compost is then allowed to undergo secondary composting in which ligno-cellulosic compound are broken down, a compost suitable for soil improvement by spreading on the land thus being formed.While this method has been performed satisfactorily in warm climates, difficulties arise in the wetter, colder kind of climate that is prevalent in Northern Europe.
The reason for the difficulty is that the air that is blown through the piles in primary composting performs two functions. First, as aforesaid, it provides the necessary oxygen for biochemical oxidation of the sludge. It is preferred to employ thermophilic bacteria that profilerate at a temperatures in the range 40 to 650C. The oxidation of sludge is an exothermic process so that once the oxidation starts there is a tendency for the temperature of the pile to rise steadily. It is however undesirable to let the temperature of the pile rise to more than about 700C as such high temperatures then have the effect of killing the thermophilic bacteria.The air blown through the pile is typically effective to extract the necessary heat by evaporation of moisture to prevent the creation of excessive temperatures and this cooling is the second function performed by the air. However, in Northern European climates there are long periods of the year in which on start-up the evaporative cooling arising from aeration removes all the heat generated by any biochemical oxidation takes place and in consequence a prolonged period of time is required for the pile to reach a temperature at which the desired thermophilic bacteria flourish.
It is an aim of the present invention to provide a method that overcomes or ameliorates this difficulty in the composting of sludge or other organic solids having a relatively high biochemical oxygen demand.
According to the present invention there is provided a method of composting organic solids, comprising the steps of forming a pile of the solids, passing pure oxygen or oxygen-enriched air into the pile, monitoring the temperature internally of the pile and upon a monitored temperature of the pile reaching a chosen value, substituting for said oxygen or oxygen-enriched air a gas mixture having a lower concentration of oxygen.
The chosen temperature is preferably in the range 40 to 650 C.
Preferably, the oxygen-enriched air contains at least 50% by volume of oxygen, or pure oxygen is used instead. The oxygen-enriched air or oxygen may be introduced into the pile intermittently or continuously. Once the desired temperature has been reached, the supply of the oxygen-enriched air or oxygen is preferably stopped and a supply of air is substituted for it. The cooling provided by the air will tend to maintain the temperature of the pile at acceptable levels throughout the rest of the composting period. Typically, the desired temperature in the range of 40 to 6500 may be achieved within twelve hours from first supplying the oxygen or oxygen-enriched air when the method according to the invention is employed.Once at the choosen temperature, composting may typically be continued for sufficient time for the primary composting stage to be completed (typically 14 to 28 days).
Preferably, the oxygen or oxygen-enriched air is supplied to the pile through a plurality of pipes each having gas distribution orifices therein, the pipes typically being embedded in the pile. There is preferably an on/off valve located in a gas supply conduit leading to the said pipes, which valve is operatively associated with a thermocouple or other sensor located in the pile such that once the desired temperature has been reached a signal is generated by the thermocouple and the valve is automatically closed. The oxygen distribution pipes may also be in communcation with an air blower and the arrangement may be such that upon closure of the valve in the oxygen supply conduit, operation of the air blower is started so that air instead of oxygen is blown through the piles.
The organic solids are preferably sewage sludge that has been partially dried, although other waste organic materials having a relatively high biochemical oxygen demand such as animal slurries and vegetative refuge may be composted instead. Preferably, after being partially dried (e.g. by pressing) the organic solids are mixed with bulking material such as wood chips, peat or straw. The resulting mixture preferably has a total solids content of at least 30 S.
The method according to the present invention will now be described by way of example with reference to the accompanying drawing, in which
Figure 1 is a schematic view of apparatus for performing the invention; and
Figure 2 is a schematic end view of the apparatus shown in Figure 1.
Referring to the drawing, there is shown a concrete base 2. The concrete base 2 is preferably a square each of whose sides is 100 feet long. The upper surface of the concrete base 2 is preferably formed with a slightly raised central region and with the rest of the upper surface sloping away from the central region. This arrangement facilitates the drainage'of water from a pile undergoing composting.
The water may typically be collected in a channel (not shown) and pumped to a suitable primary sewage treatment plant (not shown). The concrete base 2 supports a shallow bed of wood chips 4. A plurality of spaced-apart, parallel, plastics gas distribution pipes 6 is disposed in the bed 4 and each pipe 6 extends from one side of the bed to an opposite side. Each pipe 6 has a large number of upwardly facing gas distribution orifices 8 formed therethrough. Typically, the space between each pair of neighbouring pipes is in the order of 10 feet. Typically, the distance between each pair of neighbouring orifices is 1 foot. The pipes 6 communicate at their inlet ends with a main oxygen supply conduit 10 which communicates with a source of oxygen (not shown). (Typically, the oxygen source comprises a storage vessel for liquid oxygen fitted with a vaporiser.The storage pressure may be arranged to transfer the oxygen to the vaporiser at a rate sufficient to give the necessary oxygen gas supply pressure.)
Once it is desired to compost a mixture of wood chips and sewage sludge, the mixture may be loaded on to a transport vehicle (not shown) and transported to the composting site and off-loaded-on to the bed 4 of wood chips. Typically, a pile 14 up to 15 feet high at its apex is formed. An elongate probe 16 is then inserted horizontally into the pile 14 typically at a level half to a third of the way up from its base. Typically, the elongate probe 16 carries a plurality of thermocouples 18 all of which are operatively associated with a chart recorder 20 so that in operation the respective temperatures at different distances from the centre of the pile 14 are shown on the chart recorder.One of the thermocouples, typically the most central one, is also operatively associated with a valve 22 in the pipe 10.
Once the temperature reaches a chosen value, say 550C, the thermocouple will generate a signal first to close the valve 22 and also to actuate a blower 24 whose inlet communicates with the ambient atmosphere and whose outlet communicates with the pipe 10.
In operation, once the pile 14 has been formed and the probe 16 inserted, oxygen is passed through the pile and composting starts. As a result of bio-chemical reaction involving the oxygen, carbon dioxide is formed and this carbon dioxide is evolved with unreacted oxygen from the exterior of the pile. As can be seen by observing the chart recorder, the temperature in the pile 14 rises steadily. After several hours, the thermocouples all attain a temperature in the order of 550C. Once this temperature has been attained by the thermocouple that is operatively associated with the valve 22 and the blower 24, a signal is generated that automatically closes the valve 22 and energises the blower 24 to blow air through the piles.The passage of the air through the pile 14 is typically effective to maintain the pile at a satisfactory temperature such that thermophilic bacteria flourish, but should the temperature arise so as to endanger these bacteria the pile can be sprayed with water by means (not shown) to hold the temperature in check, or should be temperature begin to 0 fall again below the chosen temperature of 55 C, the air supply can be shut-off and a supply of oxygen recommenced.
If desired, the valve 22 may be programmed such that during the period in which the temperature of the pile is being raised to the chosen temperature of 550C, it may be open only for predermined periods of time, say, twenty minutes in each hour.
Typically, as composting proceeds so the pile 4 settles. After from 14 to 28 days, primary composting is completed and the supply of air is discontinued. The resulting compost may then be subjected to secondary composting for a period of, say, three months.
Claims (7)
1. A method of composting organic solids, comprising the steps of
forming a pile of the solids, passing pure oxygen or
oxygen-enriched air into the pile, monitoring the temperature
internally of the pile, and upon a monitored temperature of the
pile reaching a chosen value, substituting for said oxygen or
oxygen-enriched air a gas mixture having a lower concentration of
oxygen.
2. A method as claimed in claim 1, in which the chosen temperature
is in the range 40 to 650C.
3. A method as claimed in claim 1 or claim 2, in which the
oxygen-enriched air or oxygen is introduced into the pile
intermittently.
4. A method as claimed in any one of the preceding claims, in which
the organic solids comprise sewage sludge, animal slurries or
vegetable refuge.
5. A method as claimed in any one of the preceding claims,
additionally including the step of mining the organic solids with
bulking material comprising wood chips, peat or straw.
6. A method as claimed in any one of the preceding claims, in which
the oxygen or oxygen-enriched air is supplied for a period of up
to twelve hours.
7. A method of composting organic solids substantially as herein
described with reference to the accompanying drawing.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8628174A GB2199820B (en) | 1986-11-25 | 1986-11-25 | Method of composting |
| ZA878640A ZA878640B (en) | 1986-11-25 | 1987-11-18 | Treatment of waste material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8628174A GB2199820B (en) | 1986-11-25 | 1986-11-25 | Method of composting |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8628174D0 GB8628174D0 (en) | 1986-12-31 |
| GB2199820A true GB2199820A (en) | 1988-07-20 |
| GB2199820B GB2199820B (en) | 1990-10-10 |
Family
ID=10607912
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8628174A Expired - Fee Related GB2199820B (en) | 1986-11-25 | 1986-11-25 | Method of composting |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2199820B (en) |
| ZA (1) | ZA878640B (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1990012893A1 (en) * | 1989-04-14 | 1990-11-01 | Ashbrook-Simon-Hartley Corporation | Temperature monitoring apparatus and method in a composting system |
| WO1993017091A1 (en) * | 1992-02-27 | 1993-09-02 | Bryan Brown Michael | Composting apparatus and system |
| US5461843A (en) * | 1993-10-12 | 1995-10-31 | Ag-Bag International | Method for treatment of bagged organic materials |
| WO1997007036A1 (en) * | 1995-08-18 | 1997-02-27 | Matti Jyllinmaa | A method for collection of organic waste from households and a collection bag arrangement for use in collection |
| US5724793A (en) * | 1995-08-02 | 1998-03-10 | Ag-Bag International, Ltd. | Materials bagger and system |
| EP0792856A3 (en) * | 1996-02-27 | 1998-07-29 | Messer Griesheim Gmbh | Process and device for decomposing wastes |
| EP0792855A3 (en) * | 1996-02-27 | 1998-07-29 | Messer Griesheim Gmbh | Process and device for decomposing organic wastes |
| RU2159756C2 (en) * | 1999-01-19 | 2000-11-27 | Гришин Виктор Харитонович | Method of composting of sewage water sludges |
| WO2001009062A1 (en) * | 1999-07-31 | 2001-02-08 | Messer Griesheim Gmbh | Method and device for rotting organic material |
| WO2001012573A1 (en) * | 1999-08-17 | 2001-02-22 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process for supplying gas to a plant for the anaerobic and/or aerobic microbial degradation of organic wastes |
| RU2450873C2 (en) * | 2010-08-17 | 2012-05-20 | Государственное образовательное учреждение высшего профессионального образования Самарский государственный технический университет | Method of processing oil slimes and cleaning of oil contaminated soils |
| US20210331987A1 (en) * | 2018-08-01 | 2021-10-28 | Envirokure, Incorporated | Process for Manufacturing Nutritional Compositions for Plants and Soils |
-
1986
- 1986-11-25 GB GB8628174A patent/GB2199820B/en not_active Expired - Fee Related
-
1987
- 1987-11-18 ZA ZA878640A patent/ZA878640B/en unknown
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1990012893A1 (en) * | 1989-04-14 | 1990-11-01 | Ashbrook-Simon-Hartley Corporation | Temperature monitoring apparatus and method in a composting system |
| US5049486A (en) * | 1989-04-14 | 1991-09-17 | Ashbrook-Simon-Hartley Corporation | Temperature monitoring apparatus and method in a composting system through which organic matter is moved to effect composting |
| WO1993017091A1 (en) * | 1992-02-27 | 1993-09-02 | Bryan Brown Michael | Composting apparatus and system |
| US5461843A (en) * | 1993-10-12 | 1995-10-31 | Ag-Bag International | Method for treatment of bagged organic materials |
| US5724793A (en) * | 1995-08-02 | 1998-03-10 | Ag-Bag International, Ltd. | Materials bagger and system |
| WO1997007036A1 (en) * | 1995-08-18 | 1997-02-27 | Matti Jyllinmaa | A method for collection of organic waste from households and a collection bag arrangement for use in collection |
| EP0792856A3 (en) * | 1996-02-27 | 1998-07-29 | Messer Griesheim Gmbh | Process and device for decomposing wastes |
| EP0792855A3 (en) * | 1996-02-27 | 1998-07-29 | Messer Griesheim Gmbh | Process and device for decomposing organic wastes |
| RU2159756C2 (en) * | 1999-01-19 | 2000-11-27 | Гришин Виктор Харитонович | Method of composting of sewage water sludges |
| WO2001009062A1 (en) * | 1999-07-31 | 2001-02-08 | Messer Griesheim Gmbh | Method and device for rotting organic material |
| WO2001012573A1 (en) * | 1999-08-17 | 2001-02-22 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process for supplying gas to a plant for the anaerobic and/or aerobic microbial degradation of organic wastes |
| RU2450873C2 (en) * | 2010-08-17 | 2012-05-20 | Государственное образовательное учреждение высшего профессионального образования Самарский государственный технический университет | Method of processing oil slimes and cleaning of oil contaminated soils |
| US20210331987A1 (en) * | 2018-08-01 | 2021-10-28 | Envirokure, Incorporated | Process for Manufacturing Nutritional Compositions for Plants and Soils |
| US12037297B2 (en) * | 2018-08-01 | 2024-07-16 | Envirokure Inc. | Process for manufacturing nutritional compositions for plants and soils |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8628174D0 (en) | 1986-12-31 |
| ZA878640B (en) | 1989-01-25 |
| GB2199820B (en) | 1990-10-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19991125 |