Title of Invention

"AN APPARATUS FOR THE MANUFACTURE OF COMPOST FROM BIODEGRADABLE WASTES AND METHOD THEREFOR"

Abstract

The present invention provides an apparatus for the manufacture of compost from biodegradable wastes which consists of a double walled compositing chamber which is partitioned into three chambers. Each chamber is separated from the others by perforated sheets. The uppermost and the middle chambers are used for storing the garbage for composting and the lower chamber is a collection chamber for the liquid part of the compost. A cover is provided at the top of the composter. The compost is withdrawn from a compost withdrawal means connected to the upper and middle chambers to withdraw solid compost and to the lower chamber to withdraw the liquid part of the compost.

Full Text

Field of the invention The present invention relates to a novel apparatus and method for the manufacture of compost for biodegradable wastes. Background of the invention In recent years, wastes whether domestic or industrial have resulted in pollution, serious health hazards and tremendous environmental damage. Due to several policy initiatives across the world and in India, there is a constant search for material that is recyclable in the case of bob-biodegradable wastes and for technology for waste disposal management. For example, various Governments have now banned the use of polyethylene bags which are recycled to carry or transport food items due to the inherent toxicity of the material. Initiatives are also on to reduce the level of sewage that flow into various rivers such as the Ganges. There is also a search for new biodegradable materials to replace non-biodegradable material used in packaging, containers, etc. This is because in comparative terms, biodegradable materials cause less environmental damage than non-biodegradable materials. There is also a need for new technologies for the conversion of biodegradable wastes into materials that are beneficent or at least less harmful to the environment. Solid waste management has become a priority issue due to the ever-increasing problems of waste disposal, which cause serious health hazards and environmental pollution. Compositing is an important and prevalent method of biodegradable solid waste management, having direct/indirect economic return in the form of manure. Prior art: Conventional systems of waste disposal whether of biodegradable or non-biodegradable material consisted of either burning or composting. The disposal of wastes by burning only resulted in greater environmental degradation due to increased toxicity in the air. In conventional systems of composting, garbage is normally collected in the open. Due to the presence of naturally occurring bacteria in the wastes, degradation of wastes take place. The bacteria are primarily mesophilic and aerobic, i.e. they act between 20-40°C and require oxygen for their growth. Due to the respiration of these bacteria, the temperature of the inner layer of the garbage heap increases. When the inner layer temperature reaches above 40°C, the thermophilic bacteria in the garbage grow and start degrading the wastes to compost. One of the important limitations with the earlier technology of composting is that it requires not less than 35 days to make compost from biodegradable wastes. This is because along side the increase in temperature inside the garbage heap there is also a rapid depletion of oxygen that is essential for the bacteria to survive and grow. To avoid the presence of anaerobic condition inside the garbage heap, the garbage is churned upside down at regular intervals in order to make oxygen available to the bacteria present inside the garbage heap. Thus, unless churning of the garbage is done, the upper layer of the heap has aerobic condition but is not favourable to thermophilic bacteria, while the inner layers of the heap are suited to thermophilic bacteria but are not aerobic. The whole method of churning for maintaining aerobic and thermophilic conditions simultaneously results in a considerable delay in the method of composting. Additionally, it also requires manual handling of wastes which poses serious health hazards. While the delay factor in conventional technology for composting is not really material in cases where the quantity of garbage is relatively less, it is not feasible where tonnes of garbage are produced every day such as in cities or towns. Additionally, conventional technology for composting requires a large area to implement the technology. Another disadvantage of conventional technology of composting is that manual handling of solid wastes is required resulting in serious health hazards for the workers. Churning of wastes upside down is required every week which and is done by either mechanical or manual means. In India, some commercial companies and various Governmental bodies such as Municipal corporations involved in the composting of solid wastes make heaps of garbage after separating non-biodegradables from biodegradable materials. Chemicals are applied to the garbage to make it odourless. The heap is churned upside down periodically. After 30-35 days garbage is converted into manure. Another problem of conventional methods of composting is that it is carried out in the ground resulting in the leaching out of liquid part of the compost into the soil and resulting in ground water pollution where the quantity of garbage is high. Accordingly there is a need for a new method of composting which is not only less time consuming, but also devoid of serious health hazards to the workers and retains the liquid part of the compost for subsequent use. Objects of the invention: It is an object of the invention to provide a new method of conversion of biodegradable wastes into compost with less lead time and with minimal delay in the method of composting. It is another object of the invention to provide a method of composting wherein serious health hazards to garbage workers are reduced. It is a further object of the invention to provide a method for composting of solid wastes which does not cause serious levels of pollution in ground water levels and in the air during the disposal method. It is a further object of the invention to provide a method for composting which retains the liquid part of the compost for subsequent use. It is a further object of the invention to provide an apparatus for the manufacture of compost which is mobile and can be moved from location to location to minimise the carriage costs of transporting garbage to various landfills. It is a further object of the invention to provide a method for the manufacture of compost from solid biodegradable waste and an apparatus for utilisation in the said method which can be adapted to handle different quantities of garbage, depending upon requirement. It is another object of the invention to obtain pre-separated solid and liquid compost to enable easy transport and storage of both solid and liquid compost for subsequent use without an additional step of separation. Summary of the invention: Accordingly the present invention provides a novel method for the manufacture ,. of compost from biodegradable waste by the apparatus described herein comprising - providing biodegradable wastes inside an enclosure for composting; if desired, aerating said wastes by forced feeding of compressed air - permitting natural composting of the waste to occur by maintaining appropriate aerobic and thermophilic conditions inside the apparatus till composting is complete; drawing off the liquid compost from the bottom end of the enclosure by any conventional method; separating solid compost so produced. In another embodiment, the feeding of compressed air into the composting apparatus is done every 24 hours. In a further embodiment, the feeding of air into the composting apparatus is done for short intervals of time, i.e. for 2 to 5 minutes only. In a still further embodiment of the invention, the method utilises solid and semi-solid biodegradable organic wastes. In another embodiment, the method of the invention results in compost with a plant nutrient content of 0.89 to 2.4 % nitrogen, 1.5 to 3.5 % phosphate, 1.2 to 3.5 % potassium depending on the nature of the feed material. The invention also relates to a composting apparatus for the manufacture of compost from biodegradable wastes said apparatus comprising a double walled composting chamber partitioned into three chambers, said chambers being separated from each other by perforated sheets, the uppermost and middle chambers being used for storing the garbage for composting, the lower chamber being a collection chamber of liquid part of the compost; a cover provided at the top end of the composter; compost withdrawal means connected to said chambers for the withdrawal of solid compost from the uppermost and middle chambers and liquid compost from the lower chamber respectively. In another embodiment of the invention, aerating means may be provided connected to the uppermost and middle compartments for forced feeding air into the wastes. In another embodiment of the invention, the aeration means comprises a G.I. pipe fitted with gas valves connected to an air compresser. In a further embodiment, the gap between the two walls of the apparatus is about 1.5" and the gap is filled with glass wool or any suitable material for insulation to maintain the thermophilic conditions inside the composter. In a further embodiment, the main G.I pipe (1/2" diameter) is fitted externally parallel to the composter wall. In yet another embodiment the apparatus is provided with perforated metal sheets separating the three chambers. In a further embodiment, both the top and the middle cahmbers have separate gate the size of which would depend upon the application. In a further embodiment, the apparatus is provided with at least one outlet near the top of the plant from where gas generated inside plant, is allowed to escape. The perforated sheets may preferably be of aluminium or iron. Brief Description of the accompanying drawings: The invention will be further described and illustrated with reference to accompanying figure 1. Figure 1 represents a line drawing of an apparatus for the manufacture of compost from biodegradable waste in accordance with the method of the invention. Description of preferred embodiments: The method of the present invention requires only 5-6 days to make compost from any biodegradable waste. Churning of waste is not required at all. The technology is based on thermophilic and aerobic method. The composter can be made up of iron or aluminium sheet and is cylindrical in shape. The size of the apparatus depends upon the quantum of garbage to be composted and the site of application. A composter of 250 kg. working capacity of garbage is of 7 ft. height and 2.5 ft diameter. If desired, the entire apparatus can be fitted with wheels to enhance the mobility and to cut down on the carriage costs of transporting garbage to the disposal site. The composting apparatus is partitioned into three parts by fitting two perforated iron/aluminium sheets at different heights. Top of the plant is covered with a lid of the same material. Complete structure is a double wall structure. The gap size of the two walls is 1.5". It is filled with glass wool which acts as insulator. The uppermost and middle compartments of the plant are filled with garbage from the top of the plant. The lower part of the composter is used as collection chamber of liquid generated during composting in the two compartments. The liquid has good manurial value. The liquid compost contains total nitrogen content of 300-400 mg/1, potassium content of 2000-2500 mg/1 and a phosphate content of 5 to 20 mg/1 depending on the quality of the feed material. The liquid part is taken out through small pipe fitted with valve in the bottom of the plant. Normally, the composter compartments are not filled to the brim with the feed waste. The provision of space inside each chamber allows the aerobic and thermophilic bacteria to exploit the aerobic and thermophilic conditions and results in faster degradation of the waste into compost. The presence of perforated metal sheets dividing the chamber into three compartments is useful to enable the aerobic bacteria on the upper and lower layers of the feed waste in each chamber to exploit the aerobic conditions present above and below the feed respectively. The perforations in the metal dividing sheets also allows the drainage of the liquid compost into the third and bottom compartment for easy removal. To maintain aerobic condition inside plant, aeration may be done in both the upper compartments by aeration means such as through G.I. pipe fitted with gas valves. The main G.I pipe (1/2" diameter) is fitted externally parallel to the composter wall. Above the perforated sheets a pipe is inserted into the plant which lies above the perforated sheet. The distance from sheet to G.I. pipe (side pipe) varies from 2"-4". The end of G.I. pipe is plugged and its bottom part is perforated. Both the side pipes are connected with gas valve at the point of its origin from the main pipe. Compressed air by any conventional air compressor is allowed to flow into plant once in 24 hours for 2-5 minutes only. The provision of aeration means assists in reducing any odour due to formation of hydrogen sulphide which may occur due to anaerobic conditions inside the composter. Both the compartments have separate gates, the size of which can be fixed according to the requirements of garbage disposal. The size of the gates is usually I1 (length) x 1' (width) . There is one outlet near the top of the plant, fitted with 0.5" size pipe from where gas generated inside plant, is allowecr to escape. After 5-6 days, contents of the composter degrades completely. It contains about 30-40% moisture. It is taken out through doors. The solid contents of the composter can be used directly for agricultural purposes or sun-dried, stored till further use in agriculture. The plant nutrient content of this compost is 0.89 to 2.4% nitrogen, 1.5 to 3.5% phosphate, 1.2 to 3.5% potassium, depending upon the nature of feed material (solid waste). The practical utilities of this technology are (i) organic solid wastes can be efficiently converted into manure and soil conditions having direct/indirect economic return (ii) it will control diseases transmitted from wastes because at high temperature pathogens are eliminated from the wastes (iii) owing to reduction in volume, carriage cost of waste to disposal site as well as area required for landfills will be drastically reduced and (iv) spread of weed from wastes will also be controlled. The technology is more suited for wastes from fruit and vegetable markets, households, hostels, hotels, hospitals and housing colonies. We claim: 1. An apparatus for the manufacture of compost from biodegradable wastes'such as herein described apparatus comprising: a double walled composting chamber partitioned into three chambers, said chambers being separated from each other by perforated sheets the uppermost and middle chambers being used for storing the garbage for composting, the lower chamber being a collection chamber of liquid part of the compost; a cover provided at the top end of the composter; compost withdrawal means connected to said chambers for the withdrawal of solid compost from the uppermost and middle chambers and liquid compost from the lower chamber respectively. 2. An apparatus as claimed in claim 1 wherein the uppermost and middle compartments are provided with aeration means in order to maintain aerobic conditions inside the enclosures for the wastes, preferably a G.I. pipe fitted with gas valves connected to an air compressor. 3. An apparatus as claimed in claim 1 wherein the gap between the two walls of the apparatus is about 1.5". 4. An apparatus as claimed in claim 1 and 3 wherein the gap between the walls of the composting chamber is filled with suitable material for insulation such as herein described to maintain the thermophillic conditions inside the composter. 5. An apparatus as claimed in claim 4 wherein said insulating material is glass wool. 6. An apparatus as claimed in claim 1 wherein the main G.I. pipe is connected externally parallel to the composter wall. 7. An apparatus as claimed in claim 1 wherein the upper and middle compartments are provided with separate gates of variable size. 8. An apparatus as claimed in any preceding claim wherein at least one outlet is provided near the top of the apparatus to allow the gas generated inside the chamber to escape. 9. A method for the manufacture of compost from biodegradable waste by apparatus of claim 1 comprising: providing said biodegradable wastes such as herein described in an enclosure; optionally aerating said wastes by forced feeding of compressed air thereinto: permitting natural composting of the waste to occur by maintaining appropriate aerobic and thermophillic conditions inside the enclosure till composting is complete; drawing off the liquid compost from the bottom of the enclosure by any conventional method; separating the solid compost so produced. 10. A method as claimed in claim 9 wherein the feeding of compressed air into the composting apparatus is carried out every 24 hours. 11. A method as claimed in claim 10 wherein the feeding of compressed air into the composting apparatus is carried out for short intervals of time in the range of 2 to 5 minutes. 12. A method as claimed in claim 9 to 11 wherein the solid biodegradable waste comprises solid biodegradable organic waste. 13. A method as claimed in claim 9 wherein the final product comprises solid compost with a plant nutrient content of 0.89% to 2.4% nitrogen, 1.5 to 3.5% phosphate, 1.2 to 3.5% potassium depending on the nature of the feed material. 14. A method as claimed in any preceding claim 9 to 13 wherein the biodegradable waste feed material is selected from solid and semisolid wastes. 15. A method for the manufacture of compost from biodegradable waste substantially as described herein before. 16. An apparatus for the manufacture of compost from biodegradable waste by the method of claim 1, substantially as described hereinbefore and as illustrated in the accompanying drawings.

Documents:

743-DEL-1999-Abstract.pdf

743-DEL-1999-Claims.pdf

743-del-1999-correspondence-others.pdf

743-del-1999-correspondence-po.pdf

743-DEL-1999-Description (Complete).pdf

743-DEL-1999-Drawings.pdf

743-DEL-1999-Form-1.pdf

743-del-1999-form-19.pdf

743-DEL-1999-Form-2.pdf

743-del-1999-form-4.pdf

743-del-1999-gpa.pdf

abstract.jpg