JP6721249B2 - Liquid fertilizer manufacturing method - Google Patents

Description

The present invention relates to a method for producing a liquid fertilizer for producing a liquid fertilizer, and particularly to a method for producing a liquid fertilizer from a sanitary article such as a used paper diaper.

In recent years, liquid fertilizers (hereinafter also referred to as “liquid fertilizers”) have been manufactured using general waste, sludge, and the like as raw materials. Municipal waste and sludge contain fertilizer components that are beneficial to the soil where agricultural products are grown, and these fertilizer components are effectively used as liquid fertilizer. Patent Document 1 proposes a method for producing such a liquid fertilizer.

In the liquid fertilizer production method proposed in Patent Document 1, by concentrating excess sludge generated by activated sludge treatment (biological treatment) of organic sludge, ozone gas is efficiently brought into contact with sludge and sludge cells are removed. A solubilized liquid that is destroyed, promotes solubilization, and is returned to the activated sludge process is taken out, and fermentation, sterilization, and aging processes for solubilization are sequentially performed to produce liquid fertilizer.

JP, 2013-133242, A

However, in the liquid fertilizer production method, when liquid fertilizer is produced from organic wastewater, biological treatment is performed to generate excess sludge, the excess sludge is solubilized, the solubilized liquid is fermented, sterilized, and aged. Therefore, a plurality of processing steps such as sterilization and disinfection are required until liquid fertilizer is manufactured. Therefore, there is a problem that the manufacturing cost of the manufactured liquid fertilizer becomes high.

Therefore, the present invention, when producing liquid fertilizer from wastewater such as organic wastewater, does not require a plurality of treatment steps, it is an object of the present invention to provide a method for producing a liquid fertilizer does not increase the manufacturing cost of the liquid fertilizer And

In order to solve the above-mentioned problems and achieve the object, a first aspect of the present invention is a method for producing a liquid fertilizer from a wastewater obtained by treating a sanitary article such as a used paper diaper, the method comprising: Agitating the sanitary article with water, a disintegrant, a disinfectant/sterilizer, and a stirring step of decomposing the hygiene article into a plurality of types of materials constituting the hygiene article, and the water obtained by decomposing the hygiene article into a plurality of types of materials, The decomposing agent, a primary drainage withdrawal process for taking out primary drainage containing the disinfectant/bactericide, and a pulp recovery process for recovering pulp from a plurality of types of materials constituting the sanitary article from the removed primary drainage, recovering a secondary waste extraction step of taking out the secondary waste after the recovery of the pulp, Tona is, after the secondary waste extraction step, filtering the secondary effluent to separate solid and water and the filtrate And a filtering step to perform.

A second aspect of the present invention is characterized in that the decomposing agent is slaked lime and the disinfecting/sterilizing agent is hypochlorite.

According to the present invention, the wastewater after the hygiene products are decomposed into a plurality of materials contains a fertilizer component beneficial to the soil for cultivating agricultural products, so the wastewater after treating the used hygiene products is It becomes liquid fertilizer. In this case, since liquid fertilizer can be produced simply by decomposing hygiene products into multiple materials, when producing liquid fertilizer from wastewater, multiple treatment steps are not required, and the manufacturing cost of liquid fertilizer increases. There is no.

FIG. 1 is a process diagram showing a method for producing a liquid fertilizer according to an embodiment of the present invention. FIG. 2 is a chart showing the analysis results of the components of the liquid fertilizer produced by the method for producing liquid fertilizer according to the embodiment of the present invention. FIG. 3 is a chart showing the amount of bacteria contained in the liquid fertilizer produced by the method for producing liquid fertilizer according to the embodiment of the present invention.

Hereinafter, a method for producing a liquid fertilizer according to an embodiment of the present invention will be described. The method for producing a liquid fertilizer according to the embodiment of the present invention finally discharges a used paper diaper 1 as a used hygiene product by decomposing it into a plurality of types of materials constituting the used paper diaper 1 and treating the material. The wastewater that is collected is collected to produce liquid fertilizer.

The method for producing a liquid fertilizer according to the present embodiment is a method for producing a liquid fertilizer that produces liquid fertilizer from wastewater obtained by treating a used paper diaper 1, in which the collected used paper diapers 1 are treated with water 2 and a decomposer 3 , A stirring and decomposition step 5 of stirring together with the disinfectant/sterilizing agent 4 to decompose the used paper diaper 1 into a plurality of types of materials, and water 2 and a decomposer 3 in which the used paper diaper 1 is decomposed into a plurality of types of materials, Primary wastewater removal step 7 for removing the primary wastewater containing the treatment liquid 6 composed of the disinfectant/bactericide 4, and pulp recovery for recovering pulp 8 out of the plurality of types of materials constituting the used paper diaper 1 from the removed primary wastewater The process 9 and a secondary drainage removal process 10 for removing the secondary drainage after collecting the pulp 8 are included.

In addition, the method for producing liquid fertilizer according to the present embodiment has, after the secondary drainage extraction step 10, a filtration recovery step 11 that filters the secondary wastewater to separate solid matter and liquid and recover the filtrate. Further, in the liquid fertilizer manufacturing method according to the present embodiment, the decomposing agent 3 is slaked lime, and the disinfecting/sterilizing agent 4 is hypochlorous acid.

Next, each step of the method for producing liquid fertilizer will be specifically described with reference to FIG. In the stirring and decomposition step 5, the used paper diapers 1 collected from general households, hospitals, facilities, etc. are separated using the separator 12. The separator 12 includes a cylindrical outer shell tank and an inner shell tank rotatably provided in the outer shell tank. The inner shell tank is provided with holes formed by punching or the like over the entire outer circumference. ing. The collected used paper diapers 1 are put into the inner tank. Water 2, slaked lime 3 as a decomposing agent, hypochlorite as a disinfecting/sterilizing agent 4, and detergent 13 for cleaning are supplied into the inner tank.

The used paper diaper 1 is thrown in, and the used paper diaper 1 is constructed by rotationally driving the inner tank supplied with water 2, slaked lime (decomposing agent) 3, hypochlorous acid (disinfectant/sterilizer) 4, and detergent 13. Decompose into multiple types of materials. In this case, the high molecular weight polymer constituting the used paper diaper 1 is also decomposed and finally decomposed into plural kinds of materials such as pulp, plastic and the like. These pulps, plastics, and others are mixed in the treatment liquid consisting of water 2, slaked lime 3, hypochlorous acid 4, and detergent 13. The treatment liquid 6 composed of water 2, slaked lime 3, hypochlorous acid 4, and detergent 13 is stirred with the used paper diaper 1 in the inner barrel tank while being heated by the boiler 14.

When the used paper diaper 1 is stirred in the inner tank with the treatment liquid 6, the used paper diaper 1 is decomposed into solids such as pulp, plastic and the like, and is mixed in the treatment liquid 6. From this state, the treatment liquid 6 is discharged from the inner barrel tank in the primary drainage removing step 7 while leaving solid pulp, plastic, etc. in the inner barrel tank, and the primary drainage is taken out from the inner barrel tank. ..

After the primary drainage is taken out, pulp and plastic remain as a dehydrated solid matter in the inner shell tank in a mixed state. The pulp and plastic remaining in the inner tank are dried through a drying step 15 to be sorted into pulp and plastic. The selected pulp is recovered, and the plastic is used as a raw material for solid fuel (RPF).

In addition to the treatment liquid 6, the wastewater (sewage) absorbed by the high-molecular polymer and pulp dissolved in the treatment liquid 6 are contained in the primary wastewater taken out in the primary wastewater removal step 7. The pulp is recovered in the pulp recovery step 9. In the pulp collecting step 9, the solid portion and the liquid portion are separated by the rotary screen, and the pulp that is the solid portion is taken out. The liquid portion is taken out from the rotary screen in the secondary drainage taking step 10.

The pulp 8 which is the fixed part taken out by the rotary screen is screw-dewatered in the screw dewatering step 16 and collected. The recovered pulp 8 is washed in the washing/drying step 17, dried and reused as a pulp raw material.

The secondary wastewater discharged from the rotary screen is filtered in a filtration and recovery step 11 to remove pulp, plastic, and other fixed substances contained in the secondary wastewater, which cannot be separated and recovered, and a filtrate is obtained. Be recovered. This filtrate contains a fertilizer component useful for the soil for cultivating agricultural products, and becomes liquid fertilizer in the liquid fertilizer forming step 18. The components of the filtrate recovered in the filtration recovery step 11 will be described below.

FIG. 2 shows the normal wastewater NO. 1, normal wastewater NO. 2, and normal wastewater NO. 2 discharged from the three treatments of the used disposable diaper 1 as a sample by each process except the filtration and recovery process 11. 3 and the normal chemical wastewater stored in a container (bucket) with the lid closed and stored in the soil for 3 years stored water NO.1, 3 years stored water NO.2, biochemical oxygen demand (BOD), chemical Oxygen demand (COD), total organic carbon (TOC), contained components and their contents, and hydrogen ion concentration (pH) of five samples are shown. Therefore, the normal drainage 1, 2, 3, 3 years storage water 1, 2 which is a sample is the secondary drainage in which the solid matter and the liquid are mixed.

The biochemical oxygen demand (BOD) was measured according to JIS K 0102 21 and 32.3, and the chemical oxygen demand (COD) was measured according to JIS K 0102 17. The measurement of total organic carbon (TOC) was performed based on JIS K 0102 22.1. Moreover, the measurement of total nitrogen was performed based on JIS K 0102 45.6, the measurement of total phosphorus was performed based on JIS K 0102 46.3.4, and the measurement of potassium was performed by acid decomposition-ICP method. It was Furthermore, the measurement of magnesium was performed based on JIS K 0102 51.3. The hydrogen ion concentration (pH) was measured according to JIS K 0102 12.1.

As shown in the table of FIG. 2, the normal wastewater 1, 2, and 3 when the used paper diaper 1 is treated by the above process contains nitrogen, phosphorus, and calcium. Further, the normal wastewater 1, 2, 3 contains magnesium and potassium. These nitrogen, phosphorus, calcium, magnesium, and potassium are fertilizer components useful for soil for cultivating agricultural products, and these fertilizer components are usually contained in any of drainages 1, 2, and 3. Therefore, these normal drainages 1, 2, 3 can be used as liquid fertilizer.

Further, the normal drainage 1, 2, and 3 show that the hydrogen ion concentration (pH) is alkaline. Therefore, when the soil in which the agricultural product is to be cultivated is acidic, the soil can be neutralized by sprinkling the drainages 1, 2, and 3 on the soil, and can also be used as a soil conditioner.

Further, the normal drainage 1, 2, 3 is a very dirty liquid when looking at the BOD, COD, and TOC analysis results, but it is disinfected and sterilized by treating the used paper diaper 1 by the above process. There is. As shown in FIG. 3, the number of general bacteria contained in normal wastewater Nos. 1, 2, and 3 was 2.5×10 ⁴ , 3.1×10 ³ , 1.7×10 ³ (cells/g). Is becoming This numerical value is much lower than the standard value of bacteriological specifications for cut vegetables, for example. The standard value of bacteriological standard for cut vegetables is defined as 1×10 ⁶ or less. The coliform group was 0 (pieces/g), and Staphylococcus aureus was not detected. Therefore, general bacteria do not have a bad influence on the environment and the human body even if they are contained in the wastewater Nos. 1, 2, 3, and 3 years stored water Nos. 1 and 2.

Furthermore, the wastewater when the used disposable diaper 1 was treated in the above process was stored in the soil for 3 years, and the stored water 1 and 2 for 3 years was nitrogen and phosphorus, although the amount was lower than the amount originally contained. , Calcium, magnesium and potassium remain, and it has a sufficient capacity as a liquid fertilizer.

Further, as shown in the table of FIG. 3, the number of general bacteria contained in 3 years storage water 1 is at 6.9 × 10 ⁵ (number /g),1.1×10 ⁵ (number / g) , Coliform and Staphylococcus aureus were not detected.

As described above, according to the method for producing a liquid fertilizer according to the present embodiment, the drainage after the used paper diaper 1 as a hygiene product is decomposed into a plurality of materials is beneficial to the soil for cultivating a crop. Since it contains various fertilizer components, the wastewater after treating the used disposable diaper 1 becomes liquid fertilizer. In this case, since the liquid fertilizer can be produced only by decomposing the used paper diaper 1 into a plurality of raw materials, a plurality of treatment steps are not required when producing the liquid fertilizer from drainage, and the liquid fertilizer production cost is increased. Never.

Further, according to the method for producing a liquid fertilizer according to the present embodiment, when the used paper diaper 1 is decomposed into a plurality of kinds of materials in the stirring decomposition step, water 2, slaked lime (decomposing agent) 3, hypochlorous acid ( Since a treatment liquid including a disinfectant/sterilizer) 4 and a detergent 13 is used, slaked lime, that is, lime, is contained in the wastewater taken out in the secondary wastewater taking-out step.

It is known that lime has an action of increasing disease resistance, a bacteriostatic action by increasing pH of leaf surface/ground surface, and an action of strengthening cell wall of agricultural products in cultivation of agricultural products. In the liquid fertilizer manufacturing method according to the present embodiment, since the manufactured liquid fertilizer contains lime in the secondary drainage, the liquid fertilizer is suitable for cultivated agricultural products.

Further, according to the liquid fertilizer manufacturing method of the present embodiment, since the wastewater taken out in the secondary wastewater removing step can be used as the liquid fertilizer as it is, unnecessary components for removing the wastewater into the liquid fertilizer are removed. You can save time. Further, according to the liquid fertilizer production method of the present embodiment, the used disposable diapers 1 that have been separately collected are decomposed into a plurality of types of raw materials in the stirring decomposition process, and pulp is extracted from the wastewater taken out in the primary wastewater removal process. The pulp can be recovered in the recovery step, and the wastewater extracted in the secondary wastewater extraction step can be directly used as liquid fertilizer.

Also, by filtering the wastewater extracted in the secondary wastewater removal process in the filtration recovery process, the solid matter in the wastewater can be easily removed. Since the removed solid matter is small, small-scale incineration is possible. Can be processed at the facility.

In the above embodiment, the waste water taken out in the secondary waste water removal step is filtered in the filtration recovery step, but this filtration recovery step is not always necessary and was taken out in the secondary waste water removal step. The drainage may be used as liquid fertilizer as it is. Further, the solid component recovered in the filtration recovery step is nitrogen, phosphorus, calcium, magnesium solidified, and if these solid components are made into powder without incineration, the solid components also It can be used as fertilizer.

While the embodiments of the invention have been disclosed above, it will be apparent that modifications can be made by those skilled in the art without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the claims.

The method for producing a liquid fertilizer according to the present invention can be produced from other sanitary articles such as a urine absorbing pad in addition to the production from a used paper diaper, and is a liquid in all hygiene articles capable of absorbing dirt by a polymer. Fertilizer can be produced.

1 Used paper diapers 5 Stirring decomposition process 7 Primary drainage removal process 9 Pulp recovery process 10 Secondary drainage removal process 11 Filtration recovery process

Claims (2)

A method for producing liquid fertilizer, comprising producing liquid fertilizer from wastewater obtained by treating sanitary goods such as used paper diapers,
A stirring step of stirring the collected hygiene products together with water, a disintegrating agent, and a disinfectant/sterilizer to decompose them into a plurality of types of materials constituting the hygiene products,
Primary water discharge process for extracting the primary waste water containing the water, the decomposer, and the disinfectant/sterilizer, which is obtained by decomposing the hygiene article into a plurality of materials.
A pulp recovery process for recovering pulp from a plurality of types of materials constituting the sanitary article from the extracted primary wastewater,
A secondary waste extraction step of taking out the secondary waste after the recovery of the pulp, Ri Tona,
After the secondary wastewater removal step, a filtration step of filtering the secondary wastewater to separate solids and water and recover a filtrate,
A method for producing liquid fertilizer, comprising: The method for producing a liquid fertilizer according to claim 1, wherein the decomposing agent is slaked lime, and the disinfecting/sterilizing agent is hypochlorous acid .

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