Treatment of organic waste

Abstract

The present invention relates to a process for treating organic waste, which comprises the step of contacting an organic waste with one or more microorganisms from at least three of the following microorganism species: Bacillus sp. microorganisms, Pseudomonas sp. microorganisms, Bifidobacterium sp. microorganisms and Lactobacillus sp. microorganisms, the contacting being undertaken under conditions to at least partly convert the organic waste to organic fertilizer.

Claims

1. A process for treating organic waste, the process comprising the step of contacting an organic waste having a moisture content ranging from about 10% (wt) to about 22% (wt) with one or more microorganism species from each of at least three of the following microorganism groups presented in (i)-(iv): (i) Bacillus sp. microorganisms, selected from the group consisting of Bacillus pumilus, Bacillus stearothermophilus, Bacillus brevis, Bacillus cereus, Bacillus subtilis, Bacillus sphearieus and Bacillus licheniformis; (ii) Pseudomonas sp. microorganisms, selected from the group consisting of Pseudomonas alcaligenes and Pseudomonas marinoglutinosa; (iii)Bifidobacterium sp. microorganisms, which is Bifidobacterium thermophiles; and (iv)Lactobacillus sp. microorganisms, selected from the group consisting of Lactobacillus casei, Lactobacillus plantarum and Lactobacillus fermentus; and wherein said contacting includes mixing the organic waste with the microorganisms under aerobic environment for 18 to 30 hours to convert said organic waste to organic fertilizer.

2. A process as claimed in claim 1, further comprising the step of contacting said organic waste with one or more microorganisms selected from the group consisting of Streptomyces sp. microorganisms, and Corynebacterium sp. microorganisms.

3. A process as claimed in claim 1, wherein said contacting further comprises the step of adding an additional composition comprising one or more microorganism species from each of at least three of the microorganism groups selected from Bacillus sp. microorganisms, Pseudomonas sp, microorganisms, Bifidobacterium sp. microorganisms, and Lactobacillus sp. microorganisms to said organic waste.

4. A process as claimed in claim 3, wherein said composition further comprises one or more microorganisms selected from the group consisting of Streptomyces sp. microorganisms and Corynebacterium sp. microorganisms.

5. A process as claimed in claim 4, wherein the Streptomyces sp. is Steptomyces pactum and the Corynebacterium sp, is Corynebacterium striatum.

6. A process as claimed in claim 1, further comprising heating said organic waste to a temperature of 80? C. to 175? C. prior to said contacting step, to remove unwanted microorganisms from said organic waste.

7. A process as claimed in claim 6, further comprising the step of cooling said organic waste to a temperature of 35? C. to 75? C. prior to said contacting step.

8. A process as claimed in claim 3, wherein said composition is a solution.

9. A process as claimed in claim 3, wherein said composition is a powder.

10. A process as claimed in claim 8, wherein the microorganism content of said solution comprises 5% (vol) to 50% (vol) microorganisms in a microorganism culture.

11. A process as claimed in claim 9, wherein the microorganism content of said powder comprises 1?10.sup.10 viable microorganisms per gram of powder to 15?10.sup.10viable microorganisms per gram of powder.

12. A process as claimed in claim 3, wherein the microorganisms of said microorganism composition are one or more microorganisms selected from the group consisting of Streptomyces partum, Corynebacterium striatum, Bacillus pumilus, Bacillus stearothermophilus, Bacillus brevis, Bacillus cereus, Bacillus subtilis, Bacillus sphearieus, Bacillus licheniformis, Pseudomonas alcaligenes, Pseudomonas marinogiutinosa, Bifidobacterium thermophiles, Lactobacillus easel, Lactobacillus plantarum and Lactobacillus fermentus.

13. A process as claimed in claim 1, wherein said organic waste is selected from the group consisting of agricultural waste, food waste, organic refuse, mill effluent, municipal waste, sewage, sludge, animal waste, and industrial waste.

14. A process as claimed in claim 13, wherein said agricultural waste is selected from the group consisting of oil palm empty fruit bunch, olive husk, corn cob, coffee bean husk, rice husk, rice straw, spent mushroom compost, palm foliage, palm trunk, palm kernel shells, palm fiber, farm effluent, slaughterhouse waste, flower cuttings, spent flower compost, wheat straw, fruit waste, and vegetable waste.

15. A process as claimed in claim 13, wherein said animal waste is selected from the group consisting of poultry manure, cow manure, goat manure, horse manure, sheep manure, and swine manure.

16. A process as claimed in claim 1, wherein said organic waste has a particle size of 1 mm to 20 mm.

17. A process as claimed in claim 1, further comprising adding one or more additives or nutrients to said organic waste to enhance conversion of said organic waste by said microorganisms.

18. A method of using one or more microorganism species from each of at least three of the following microorganism groups presented in (i)-(iv): (i) Bacillus sp, microorganisms, selected from the group consisting of Bacillus pumilus, Bacillus stearothennophilus, Bacillus brevis, Bacillus cereus, Bacillus subtilis, Bacillus sphearieus and Bacillus licheniformis; (ii) Pseudomonas sp, microorganisms, selected from the group consisting of Pseudomonas alcaligenes and Pseudomonas marinogiutinosa; (iii)Bifidobacterium sp. microorganisms, which is Bifidobacterium thermophiles; and (iv)Lactobacillus sp, microorganisms, selected from the group consisting of Lactobacillus casei, Lactobacillus plantarum and Lactobacillus fermentus; the method comprising: adjusting an initial moisture content of an organic waste between about 25% (wt) and about 70% (wt); adjusting a subsequent moisture content of said organic waste between about 10% (wt) to about 22% (wt) heating said organic waste to a temperature of 80?C. to 175?C. to remove unwanted microorganisms from said organic waste; cooling said organic waste to a temperature of 35?C. to 75? C.; and contacting said organic waste with the one or more microorganism species under aerobic environment for 18 to 30 hours for treating said organic waste to produce organic fertilizer, increase the NPK value of an organic fertilizer, increase the potassium value of an organic fertilizer, reduce odour of an organic waste, prevent leaching of nutrients from organic waste, or reduce waste accumulation.

19. The method as claimed in claim 18, further comprising contacting the organic waste with microorganisms selected from the group consisting of Streptomyces sp, microorganisms and Corynebacterium sp. microorganisms.

20. The method as claimed in claim 19, wherein said microorganism is selected from the group consisting of Streptomyces pactum and Corynebacterium striatum.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The accompanying drawings illustrate a disclosed embodiment and serves to explain the principles of the disclosed embodiment. It is to be understood, however, that the drawings are designed for purposes of illustration only, and not as a definition of the limits of the invention.

(2) FIG. 1 shows a schematic diagram of a system for treating organic waste according to one disclosed embodiment.

DETAILED DESCRIPTION OF DRAWINGS

(3) Referring to FIG. 1, there is shown one embodiment of the disclosed system. In this embodiment, the system 100 comprises an input conveyor belt 102 for transporting an organic waste into a treatment zone 104 via an inlet 106. The treatment zone 104 is placed on a support 107, and is equipped with heating means 108 and stirring means 109. The stirring means 109 has four arms 109a, 109b, 109c and 109d, located at two different heights and extending radially from the longitudinal axis 111 of the treatment zone 104. The stirring means are controlled by a motor 110 and a decelerator 110a. The treatment zone 104 is covered by cover 112, which is equipped with an output conveyor belt 116 via outlet 114. A control unit 118 is also attached to the cover 112.

(4) Once the organic waste is transported by the input conveyor belt 102 into the treatment zone 104 via inlet 106, the organic waste is heated to about 50? C. by the heating means 108, and a composition of selected microorganisms is added. The mixture of organic waste and microorganism composition is uniformly mixed by stirring means 109, the rate of stirring being controlled by the motor 110 and a decelerator 110a. The treatment of the organic waste is allowed to proceed for 2 h. The treated organic waste product is then removed from the treatment zone after 24 h by the output conveyor belt 116 via the outlet 114.

EXAMPLES

(5) (A) Preparation of Microorganism Composition

(6) 1 L of nutrient broth was prepared by mixing 10 g glucose, 8 g yeast extract and 5 g sodium chloride. The nutrient broth was then inoculated with the selected microorganisms: Streptomyces pactum, Corynebacterium striatum, Bacillus pumilus, Bacillus stearothermophilus, Bacillus brevis, Bacillus, cereus, Bacillus subtilis, Bacillus sphearieus, Bacillus licheniformis, Pseudomonas alcaligenes, Pseudomonas marinoglutinosa, Bifidobacterium thermophilus, Lactobacillus casei, Lactobacillus planatarum and Lactobacillus fermentus. The nutrient broths inoculated with Streptomyces pactum, Corynebacterium striatum, Bacillus pumilus, Bacillus brevis, Bacillus cereus, Bacillus sphearieus, Pseudomonas alcaligenes, Pseudomonas marinoglutinosa, Lactobacillus casei, Lactobacillus planatarum and Lactobacillus fermentus were cultured at 37? C., while the nutrient broths inoculated with Bacillus stearothermophilus, Bacillus subtilis, Bacillus licheniformis, and Bifidobacterium thermophilus were cultured at 60? C.

(7) (B) Analytical Methods

(8) NPK Values

(9) Standard Kjeldahl's method (APHA 4500 N.sub.org B) was used to determine the total nitrogen content in the organic fertilizer. Standard acid digestion of the organic fertilizer followed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used to determine the phosphorus and potassium contents in the organic fertilizer.

(10) C:N Ratio

(11) The organic carbon content was determined using the standard Loss on Ignition (LOI) method. A sample of the organic waste or organic fertilizer was weighed and its initial weight recorded. The sample was then placed in an oven at 350? C. for 3 hr. The sample was then cooled, re-weighed, and its final weight recorded. The organic carbon content was determined as follows:
% Organic Carbon=(Loss in weight?Initial Weight)?100

(12) The nitrogen content was determined using standard Kjeldahl's method (APHA 4500 N.sub.org B).

(13) The C:N ratio was then determined as follows:
C:N Ratio=% Organic Carbon:% Nitrogen

Example 1

Preparation of Organic Fertilizer from Raw Chicken Manure

(14) Raw chicken manure, dead chicken and chicken feathers were mixed with saw dust, ash, rice husks, rice straw, wheat straw, spent mushroom compost or corn cobs. The initial moisture content of the organic waste mixture was adjusted to 35-60% (wt) for the first 6 h, and re-adjusted to and maintained at 15-20% (wt) thereafter. The mixture was heated to 100-150? C. for the first 2 h, after which the mixture was cooled to 50-65? C. The microorganism composition as prepared above was added to the mixture.

(15) After mixing the mixture and microorganism for 2 h, air was pumped in for 10 min, stopped for 20 min, and resumed for another 10 min to maintain an aerobic environment. The process was allowed to run for 22 h, and then cooled. Air was pumped into the mixture for 3-4 h, after which the treated organic waste was allowed to age for 2 days. The NPK values and C:N ratios were determined using the analytical methods set out above.

Example 1(a)

(16) TABLE-US-00001 Raw Material % wt Raw chicken manure 70 Wood chips 20 Ash 10

(17) The NPK value of the organic fertilizer produced using the raw material composition in Example 1(a) was 6.

(18) The C:N ratio of the raw material composition in Example 1(a) before treatment was 45:1. This was reduced to 20:1 after the 24 h treatment process.

Example 1(b)

(19) TABLE-US-00002 Raw Material % wt Raw chicken manure 60 Wood chips 10 Ash 30

(20) The NPK value of the organic fertilizer produced using the raw material composition in Example 1(b) was 9.

(21) The C:N ratio of the raw material composition in Example 1(b) before treatment. was 40:1. This was reduced to 19:1 after the 24 h treatment process.

Example 1(c)

(22) TABLE-US-00003 Raw Material % wt Raw chicken manure 50 Wood chips 30 Ash 20

(23) The NPK value of the organic fertilizer produced using the raw material composition in Example 1(c) was 6.

(24) The C:N ratio of the raw material composition in Example 1(c) before treatment was 50:1. This was reduced to 22:1 after the 24 h treatment process.

Example 1(d)

(25) TABLE-US-00004 Raw Material % wt Raw chicken manure 40 Dead chicken 20 Wood chips 20 Ash 20

(26) The NPK value of the organic fertilizer produced using the raw material composition in Example 1(d) was 9.

(27) The C:N ratio of the raw material composition in Example 1(d) before treatment was 42:1. This was reduced to 21:1 after the 24 h treatment process.

Example 1(e)

(28) TABLE-US-00005 Raw Material % wt Raw chicken manure 40 Chicken feathers 20 Wood chips 20 Ash 20

(29) The NPK value of the organic fertilizer produced using the raw material composition in Example 1(e) was 9.

(30) The C:N ratio of the raw material composition in Example 1(e) before treatment was 43:1. This was reduced to 20:1 after the 24 h treatment process.

Example 1(f)

(31) TABLE-US-00006 Raw Material % wt Raw chicken manure 10 Chicken feathers 50 Wood chips 20 Ash 20

(32) The NPK value of the organic fertilizer produced using the raw material composition in Example 1(f) was 9.

(33) The C:N ratio of the raw material composition in Example 1(f) before treatment was 42:1. This was reduced to 20:1 after the 24 h treatment process.

(34) As can be seen from the above Examples 1(a) to 1(f), treatment of the organic waste compositions in Examples 1(a) to 1(f) all resulted in organic fertilizers with high NPK values of at least 6. The organic waste compositions in Examples 1(b), 1(d), 1(e) and 1(f), in particular, resulted in organic fertilizers having higher NPK values of 9. Similarly, the initial C:N ratios of the organic waste compositions in Examples 1(a) to 1(f) ranging from 40:1 to 50:1 were all efficiently reduced to 19:1 to 22:1 after just 24 h.

Example 2

Preparation of Organic Fertilizer from Empty Fruit Bunch

(35) Threshed EFP particles of 5-10 mm were mixed with chicken droppings, dead chickens, goat dung, POME, EFB ash and/or ash. The initial moisture content of the organic waste mixture was adjusted to 35-60% (wt) for the first 6 h, and re-adjusted to and maintained at 15-20% (wt) thereafter. The mixture was heated to 100-150? C. for the first 2 h, after which the mixture was cooled to 50-65? C. The microorganism composition as prepared above was added to the mixture.

(36) After mixing the mixture and microorganism composition for 2 h, air was pumped in for 10 min, stopped for 20 min, and resumed for another 10 min to maintain an aerobic environment. The process was allowed to run for 22 h, and then cooled. Air was pumped into the mixture for 3-4 h, after which the treated organic waste was allowed to age for 2 days. The NPK values and C:N ratios were determined using the analytical methods set out above.

Example 2(a)

(37) TABLE-US-00007 Raw Material % wt EFB (threshed) 70 Raw chicken manure 20 Ash 10

(38) The NPK value of the organic fertilizer produced using the raw material composition in Example 2(a) was 6.

(39) The C:N ratio of the raw material composition in Example 2(a) before treatment was 75:1. This was reduced to 27:1 after the 24 h treatment process.

Example 2(b)

(40) TABLE-US-00008 Raw Material % wt EFB (threshed) 60 Raw chicken manure 20 EFB ash 20

(41) The NPK value of the organic fertilizer produced using the raw material composition in Example 2(b) was 9.

(42) The C:N ratio of the raw material composition in Example 2(b) before treatment was 70:1. This was reduced to 25:1 after the 24 h treatment process.

Example 2(c)

(43) TABLE-US-00009 Raw Material % wt EFB (threshed) 50 Raw chicken manure 20 EFB ash 10 POME 20

(44) The NPK value of the organic fertilizer produced using the raw material composition in Example 2(c) was 6.

(45) The C:N ratio of the raw material composition in Example 2(c) before treatment was 65:1. This was reduced to 23:1 after the 24 h treatment process.

Example 2(d)

(46) TABLE-US-00010 Raw Material % wt EFB (threshed) 80 POME sludge 20

(47) The NPK value of the organic fertilizer produced using the raw material composition in Example 2(d) was 4.

(48) The C:N ratio of the raw material composition in Example 2(d) before treatment was 85:1. This was reduced to 30:1 after the 24 h treatment process.

Example 2(e)

(49) TABLE-US-00011 Raw Material % wt EFB (threshed) 50 POME sludge 50

(50) The NPK value of the organic fertilizer produced using the raw material composition in Example 2(e) was 6.

(51) The C:N ratio of the raw material composition in Example 2(e) before treatment was 73:1. This was reduced to 24:1 after the 24 h treatment process.

Example 2(f)

(52) TABLE-US-00012 Raw Material % wt EFB (threshed) 50 POME sludge 30 Ash 20

(53) The NPK value of the organic fertilizer produced using the raw material composition in Example 2(f) was 7.

(54) The C:N ratio of the raw material composition in Example 2(f) before treatment was 70:1. This was reduced to 24:1 after the 24 h treatment process.

(55) As can be seen from the above Examples 2(a) to 2(f), the organic waste composition in Example 2(a) to Example 2(f) resulted in organic fertilizers having NPK values of between 4 to 9. The organic waste composition in Example 2(b), in particular, resulted in an organic fertilizer with a high NPK value of 9. Similarly, the initial C:N ratios of the organic waste compositions in Examples 2(a) to 2(f) ranging from 65:1 to 85:1 were all efficiently reduced to 23:1 to 30:1 after just 24 h.

Example 3

Preparation of Organic Fertilizer from Food Waste Sludge

(56) Food waste slurry and/or materials collected at the coarse screen station of a food processing plant were mixed with rice husks, rice straw, wheat straw, corn cobs, coffee bean husk, oil palm EFB, olive husk, fruit peels, wood chips, discarded vegetable, spent mushroom compost, spent orchid compost and/or flower cuttings. The initial moisture content of the organic waste mixture was adjusted to 35-60% (wt) for the first 6 h, and re-adjusted to and maintained at 15-20% (wt) thereafter. The mixture was heated to 100-150? C. for the first 2 h, after which the mixture was cooled to 50-65? C. The microorganism composition as prepared above was added to the mixture.

(57) After mixing the mixture and microorganism composition for 2 h, air was pumped in for 10 min, stopped for 20 min, and resumed for another 10 min to maintain an aerobic environment. The process was allowed to run for 22 h, and then cooled. Air was pumped into the mixture for 3-4 h, after which the treated organic waste was allowed to age for 2 days. The NPK values and C:N ratios were determined using the analytical methods set out above.

Example 3(a)

(58) TABLE-US-00013 Raw Material % wt Food waste sludge 50 Saw dust 25 Ash 25

(59) The NPK value of the organic fertilizer produced using the raw material composition in Example 3(a) was 6.

(60) The C:N ratio of the raw material composition in Example 3(a) before treatment was 60:1. This was reduced to 22:1 after the 24 h treatment process.

Example 3(b)

(61) TABLE-US-00014 Raw Material % wt Food waste sludge 70 Saw dust 15 Ash 15

(62) The NPK value of the organic fertilizer produced using the raw material composition in Example 3(b) was 9.

(63) The C:N ratio of the raw material composition in Example 3(b) before treatment was 50:1. This was reduced to 19:1 after the 24 h treatment process.

Example 3(c)

(64) TABLE-US-00015 Raw Material % wt Food waste sludge 60 Saw dust 10 Ash 30

(65) The NPK value of the organic fertilizer produced using the raw material composition in Example 3(c) was 9.

(66) The C:N ratio of the raw material composition in Example 3(c) before treatment was 45:1. This was reduced to 18:1 after the 24 h treatment process.

(67) As can be seen from the above Examples 3(a) to 3(c), treatment of the organic waste compositions in Examples 3(a) to 3(c) all resulted in organic fertilizers with high NPK values of at least 6. The organic waste compositions in Examples 3(b) and 3(c), in particular, resulted in organic fertilizers having higher NPK values of 9. Similarly, the initial C:N ratios of the organic waste compositions in Examples 3(a) to 3(c) ranging from 45:1 to 60:1 were all efficiently reduced to 18:1 to 22:1 after just 24 h.

APPLICATIONS

(68) Advantageously, the disclosed process for treating organic waste provides an improved process for producing organic fertilizer. More advantageously, the disclosed process substantially reduces the time required to produce organic fertilizers from several months as required using conventional composting methods to only one day or several days using the disclosed process, composition and system. Organic wastes having high C:N ratios may be rapidly converted to organic fertilizers with reduced C:N ratios after just 24 hours using the disclosed process, composition and system. This results in substantial reduction in energy and labour costs.

(69) Advantageously, the disclosed process, composition and system substantially reduces, or completely eliminates, the foul odour of organic waste, to result in an organic fertilizer that is odourless.

(70) Advantageously, the disclosed process for producing organic fertilizer from organic waste results in more effective organic fertilizers having increased NPK values.

(71) Advantageously, the disclosed process also provides a solution to the waste disposal problem by converting organic waste into useful organic fertilizers.

(72) It will be apparent that various other modifications and adaptations of the invention will be apparent to the person skilled in the art after reading the foregoing disclosure without departing from the spirit and scope of the invention and it is intended that all such modifications and adaptations come within the scope of the appended claims.