JP2006027950A - Method and apparatus for manufacturing liquid fertilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing a good quality liquid fertilizer having uniform characteristics and excellent operability for the application, containing effective components for vegetable production and a small quantity of odorous components which brings the difficulty of the application work and capable of preventing the adverse influence on vegetables due to sulfur oxide and realizing the recycling or the effective use of unutilized organic materials. <P>SOLUTION: Liquid waste 3 is made by separating and removing a solid material containing biologically hardly degradable components from organic waste 1 containing at least livestock excreta by a pretreatment 2 and is anaerobically fermented in an anaerobic fermentor 8 to obtain the liquid fertilizer 9. In such a case, sulfur components dissociated in the anaerobic fermentation is fixed as iron sulfide in the liquid fertilizer 9 by adding a liquid 5 prepared by dissolving iron chloride into the liquid waste 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for producing liquid fertilizer, and relates to a technology for converting organic waste containing at least livestock excrement into fertilizer.

  Conventionally, as this type of technology, for example, there is one described in Patent Document 1. This is because livestock manure is dehydrated with a screw press or belt press, the dehydrated cake is fermented in a solid fermenter to form solid fertilizer, and the dehydrated liquid is mixed with urine and circulated between the aerial structure and the storage tank. Incorporating oxygen in the air between the structure exposed to the atmosphere and the storage tank suppresses anaerobic fermentation on both the surface of the structure and the storage tank, thereby reducing malodor and evaporating moisture. Concentrated and aged to obtain concentrated liquid fertilizer.

  Moreover, in what is described in patent document 2, when organic waste is methane-fermented in a methane fermentation tank, the raw material supply which arrange | positions in the front | former stage of a methane fermentation tank or a methane fermentation tank, and stores organic waste In a raw material transfer system for supplying a tank or organic waste to a methane fermentation tank, a desulfurization agent composed of a liquid inorganic iron compound is added to the organic waste.

Also, those described in Patent Document 3, with the addition of iron-based coagulant organic waste to methane fermentation treatment under anaerobic conditions, Fe ²⁺ of the fermentation solution by aeration of the fermentation broth After being oxidized to Fe ³⁺ , it is separated into dehydrated separation liquid and dehydrated sludge.

Moreover, in what is described in patent document 4, in the methane fermentation process of the organic waste which can be decomposed | disassembled by anaerobic microorganisms, the hydrogen sulfide density | concentration in a methane fermenter is measured with a hydrogen sulfide concentration analyzer, and this measured value After adjusting the hydrogen sulfide concentration in the methane fermentation tank so that the value becomes below a predetermined value, a nickel compound and / or a cobalt compound is added to the methane fermentation tank.
JP 2001-314897 A JP 2002-307035 A JP 2003-275726 A JP 2004-25088 A

However, there are problems described below in converting organic waste containing livestock excrement into liquid fertilizer.
Hydrogen sulfide and sulfide ions are generated as dissolved liquid components in the dissolved solution after anaerobic fermentation of organic matter. Therefore, when applying the dissolved solution after anaerobic fermentation as liquid fertilizer, hydrogen sulfide and sulfide ions are produced. Will adversely affect plant production.

Since the solution after anaerobic fermentation tends to be deficient in phosphorus components, when the solution after anaerobic fermentation is used as a liquid fertilizer, it is necessary to apply it together with a phosphorus-based chemical fertilizer during fertilization.
Since most of the nitrogen components contained in the solution after anaerobic fermentation are ammonia nitrogen, plants to which the solution after anaerobic fermentation can be applied as a liquid fertilizer are limited.

The solution after anaerobic fermentation contains a lot of malodor-causing substances such as ammonia and hydrogen sulfide, and this malodor worsens the working environment of the user.
If a solid containing a hard-to-decompose component is mixed in the anaerobic fermentation treatment process, it causes a bad odor in the solution after anaerobic fermentation, and the undegraded solid contained in the solution after anaerobic fermentation is fermented, stored, It becomes a factor of the obstruction | occlusion of the pipe | tube obstruction | occlusion in each process at the time of fertilization, and poor operativity.

When composting organic waste containing livestock excreta, its operability is poor and labor is required for application work.
By the way, most of the nitrogen fertilizer uses ammonia as a raw material, and ammonia is produced by reacting nitrogen and hydrogen in the atmosphere under high pressure. However, the energy cost for producing hydrogen is a problem. Phosphorite ore, the main raw material for phosphate fertilizers, depends on imports, but resource depletion has become a problem, and the US has stopped exporting because of resource depletion. The raw material for potash fertilizer is potash ore, which also has a limited production country.

  The present invention solves the above-mentioned problems, has uniform properties, excellent operability for application, has components effective for plant production, has few odor components that cause difficulty in application work, and is sulfur to plants. It is an object of the present invention to provide a method and an apparatus for producing a high-quality liquid fertilizer capable of preventing the adverse effects of oxides and realizing resource recycling and effective use of underutilized organic matter.

  In order to solve the above-mentioned problems, the method for producing a liquid fertilizer according to the present invention as described in claim 1 separates a solid substance containing a biodegradable component from an organic waste containing at least livestock excrement by pretreatment. When the liquid waste is made into liquid waste by removing the liquid waste by anaerobic fermentation, a solution of iron chloride is added to the liquid waste, and sulfur components dissociated by the anaerobic fermentation are sulfided in the liquid fertilizer. It is fixed as iron.

  According to a second aspect of the present invention, there is provided a method for producing a liquid fertilizer according to the present invention by separating and removing a solid matter containing a biodegradable component from an organic waste containing at least livestock excrement by pretreatment. When making this liquid waste liquid fertilizer by anaerobic fermentation, add a plant-derived phosphate organic material to the liquid waste, and anaerobic fermentation to remove the phosphorus component that dissociates from the phosphate organic material by decomposition by microorganisms It is supplied into liquid fertilizer.

  According to a third aspect of the present invention, there is provided a method for producing a liquid fertilizer according to the present invention, wherein solid waste containing biodegradable components is separated and removed from organic waste containing at least livestock excrement by pretreatment. When the liquid waste is made into liquid fertilizer by anaerobic fermentation, the anaerobic fermentation liquid is stored in a storage tank that repeats anaerobic and anaerobic conditions to adjust the amounts of ammonia nitrogen and nitrate nitrogen components. .

  The apparatus for producing liquid fertilizer according to the present invention described in claim 4 manufactures liquid fertilizer from organic waste containing at least livestock excrement, and separates and removes solid matter containing biodegradable components. Pretreatment means to turn organic waste into liquid waste, anaerobic fermenter to make liquid waste anaerobically fermented into liquid fertilizer, and iron solution supply to add iron chloride solution to liquid waste Means, an auxiliary material adding means for adding a plant-derived phosphate-based organic substance to liquid waste, and a storage tank for storing liquid fertilizer extracted from the anaerobic fermentation tank and repeating an aerobic state and an anaerobic state Is.

  As described above, according to the present invention, at least organic waste containing livestock excrement is pretreated to obtain a liquid waste obtained by separating and removing solid matter containing biodegradable components. It is possible to prevent the decomposition products of the biodegradable components to be produced by anaerobic fermentation, to suppress malodor in the liquid fertilizer after anaerobic fermentation, and to reduce the SS concentration in the liquid fertilizer and to penetrate into the soil Is improved.

  Hydrogen sulfide in a field fertilized with liquid fertilizer by adding enough or excess iron chloride solution to liquid waste and fixing the sulfur component dissociated by anaerobic fermentation as completely insoluble iron sulfide The generation of bad odors such as gas can be suppressed, and inhibition of plant growth such as “falling fall” phenomenon of rice by hydrogen sulfide and sulfide ions can be avoided.

  Liquid fertilizer by adding phosphorous organic substances derived from plants such as rice bran and bran to liquid waste, and supplying the liquid fertilizer with phosphorus components that dissociate from phosphate organic substances by decomposition by microorganisms in anaerobic fermentation Can be supplemented without using mineral resources, and contribute to anaerobic fermentation by promoting vitamins, amino acids, trace components, etc. produced by microbial degradation of plant-derived phosphate organic substances. Can do.

  The anaerobic fermentation liquid is stored in the storage tank, the dissolved oxygen concentration in the storage tank is controlled by intermittent aeration etc. to repeat the aerobic state and the anaerobic state, and ammonia nitrogen is converted into nitrate nitrogen by nitrification in the aerobic state. Without increasing the nitrate nitrogen component in the liquid fertilizer, the amount of ammonia nitrogen and nitrate nitrogen can be adjusted as the liquid fertilizer to improve the quality, and the properties of the liquid fertilizer can be made uniform by stirring, and Scum generation can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the organic waste 1 contains at least livestock excrement, and the livestock excrement may be singly, or any combination of food residue, settlement drainage sludge, sewage sludge, etc. May be.

  Organic waste 1 is subjected to pretreatment 2 using a bar screen, screw press, belt press or the like to separate and remove solid substances containing biodegradable components such as straw and sawdust contained in organic waste 1 Thus, liquid waste 3 is obtained.

  To this liquid waste, an iron chloride solution 5 is added from an iron solution supply device 4, and rice bran or bran is added as a plant-derived phosphate organic material 7 from an auxiliary material addition device 6. In this embodiment, both the addition of the iron chloride solution 5 and the addition of the plant-derived phosphate organic material 7 are performed. Depending on the properties of the organic waste 1, the addition of the iron chloride solution 5 or The addition of the plant-derived phosphate organic material 7 may be sufficient.

The liquid waste 3 to which the iron chloride solution 5 and the plant-derived phosphate organic material 7 are added is subjected to anaerobic fermentation (methane fermentation) in an anaerobic fermentation tank 8 to form a liquid fertilizer 9.
At the time of anaerobic fermentation in the anaerobic fermenter 8, the liquid waste 3 is separated and removed from the solid matter containing the biodegradable components in the pretreatment 2, so that the biodegradable components that cause malodor are decomposed and produced. Generation of things can be suppressed. Naturally, the malodor in the liquid fertilizer 9 after anaerobic fermentation can also be suppressed, and the liquid fertilizer 9 is improved in permeability to soil due to a decrease in SS concentration.

  In addition, in the anaerobic fermentation, the sulfur component dissociated by the decomposition of the organic matter of the liquid waste 3 by anaerobic fermentation by adding the iron chloride solution 5 sufficiently or excessively to the liquid waste 3 is reduced with iron chloride. By this reaction, it is fixed as completely insoluble iron sulfide.

  For this reason, malodor generation such as hydrogen sulfide gas in a field fertilized with the liquid fertilizer 9 is suppressed, and plant growth inhibition such as “falling down” phenomenon of rice by hydrogen sulfide and sulfide ions can be avoided. Therefore, the liquid fertilizer 9 which does not have the bad influence by the sulfide to a plant and has few bad smells can be provided.

  In addition, in the anaerobic fermentation, by adding the phosphoric acid organic material 7 derived from plants such as rice bran and bran to the liquid waste 3, the phosphorus component dissociated by the decomposition of the phosphoric organic material 7 by microorganisms in the anaerobic fermentation is removed. It can be fed into the liquid fertilizer 9.

  Rice bran and bran contain not only nitrogen N, phosphorus P, and potassium K, which are the main components of fertilizer, but also magnesium Mg, calcium Ca, iron Fe, etc., which are trace elements, and are rich in vitamins and proteins (amino acids). Become a good source of nutrition and promote anaerobic fermentation.

  As shown in Table 1, in general, cattle manure and swine manure have a low phosphorus component (0.1 to 0.3%), and it is necessary to supplement the phosphorus component when considered as a fertilizer. For this reason, rice bran rich in phosphorus components (phosphorus component 5%) and bran are effective as a phosphorus component supply source. The rice bran or bran phosphorus component is hardly soluble in water and is dissolved by a weak acid such as citric acid, but dissociates when decomposed by microorganisms.

  Therefore, contact with manure or the like containing a large amount of microorganisms promotes the decomposition of rice bran and bran, and promotes the transfer of the phosphorus component contained in the rice bran and bran to the liquid fertilizer 9. As shown in Table 2, the phosphorus component greatly increases after anaerobic fermentation. Rice bran and bran are in powder form, so they can be used easily, have no specific unpleasant odor, and are easy to handle as a chemical fertilizer.

  As described above, phosphorus that is deficient in the liquid fertilizer 9 is taken out from rice bran or bran that has only been sprayed as a solid fertilizer in the past without using conventional mineral resources, and as dissolved phosphorus with immediate effect. It can be replenished and there is no need to add phosphate fertilizer in the field. Moreover, even if phosphorus becomes iron phosphate by the addition of the iron chloride solution 5, it can be prevented that phosphorus as a fertilizer component is insufficient.

  Next, the liquid fertilizer 9 taken out from the anaerobic fermentation tank 8 is stored in the storage tank 10. In the storage tank 10, the air supplied by the blower 11 is diffused from the diffuser pipe 12 to aerate the liquid fertilizer 9. This aeration is intermittently performed, and the internal environment of the storage tank 10 that naturally becomes anaerobic due to the previous anaerobic fermentation is repeatedly changed between an aerobic state and an anaerobic state.

  This intermittent aeration is performed at appropriate time intervals using the redox potential of the liquid fertilizer 9 measured by the ORP meter 13 as a control index, or using the pH value of the liquid fertilizer 9 measured by the pH meter 14 as a control index, or by a timer 15. .

  By making the internal environment of the storage tank 10 aerobic, the ammonia nitrogen contained in the liquid fertilizer 9 is converted to nitrate nitrogen by nitrification to increase the nitrate nitrogen component contained in the liquid fertilizer 9. By this operation, the amount of ammonia nitrogen and nitrate nitrogen as liquid fertilizer 9 is adjusted, and it is adjusted to the most suitable fertilizer component for plants to be cultivated such as nitric acid-containing plants and ammonia-philic plants, thereby improving quality. Can be planned. In addition, the properties of the liquid fertilizer can be made uniform and the occurrence of scum can be prevented by stirring.

  In the present embodiment, an example in which the iron chloride solution 5 is added to the liquid waste 3 to be introduced into the anaerobic fermenter 8 is shown. However, the iron chloride solution 5 is added to the liquid fertilizer 9 to be introduced into the storage tank 10. It may be added, and can be added to both the liquid waste 3 stage and the liquid fertilizer 9 stage.

The block diagram which shows the manufacturing apparatus of the liquid fertilizer in embodiment of this invention

Explanation of symbols

1 Organic waste (including livestock excreta)
2 Pretreatment 3 Liquid waste 4 Iron solution supply device 5 Iron chloride solution 6 Auxiliary material addition device 7 Phosphoric organic substance 8 Anaerobic fermentation tank 9 Liquid fertilizer 10 Storage tank 11 Blower 12 Air diffuser 13 ORP meter 14 pH 15 timers in total

Claims (4)

At least, when solid waste containing biologically degradable components is separated and removed from organic waste containing livestock excrement by pretreatment to form liquid waste, this liquid waste is converted into liquid fertilizer by anaerobic fermentation, A method for producing a liquid fertilizer, comprising adding a liquid solution of iron chloride to liquid waste, and immobilizing a sulfur component dissociated by anaerobic fermentation as iron sulfide in the liquid fertilizer. At least, when solid waste containing biologically degradable components is separated and removed from organic waste containing livestock excrement by pretreatment to form liquid waste, this liquid waste is converted into liquid fertilizer by anaerobic fermentation, A method for producing liquid fertilizer, comprising adding a plant-derived phosphate organic material to liquid waste, and supplying the liquid fertilizer with a phosphorus component that is dissociated from the phosphate organic material by decomposition by microorganisms in anaerobic fermentation . At least, when solid waste containing biologically degradable components is separated and removed from organic waste containing livestock excrement by pretreatment to form liquid waste, this liquid waste is converted into liquid fertilizer by anaerobic fermentation, A method for producing a liquid fertilizer, comprising storing an anaerobic fermentation liquid in a storage tank that repeats an aerobic state and an anaerobic state, and adjusting the component amounts of ammonia nitrogen and nitrate nitrogen. Pretreatment means for producing liquid fertilizer from organic waste containing at least livestock excrement, separating and removing solid matter containing biodegradable components and converting the organic waste into liquid waste; An anaerobic fermenter that anaerobically ferments liquid waste into liquid fertilizer, an iron solution supply means that adds an iron chloride solution to the liquid waste, and a plant-derived phosphate organic material in the liquid waste An apparatus for producing liquid fertilizer, comprising: an auxiliary material adding means to be added; and a storage tank that stores liquid fertilizer taken out from the anaerobic fermentation tank and repeats an aerobic state and an anaerobic state.

Images