KR20100090463A - Method for preparing echo-compost using the pig slurry removed the heavy metal, and the product obtained therefrom - Google Patents

Abstract

PURPOSE: A manufacturing method of an environment-friendly compost, and the environment-friendly compost manufactured therefrom are provided to remove heavy metals from livestock excretion using oxalic acid dehydrate. CONSTITUTION: A manufacturing method of an environment-friendly compost comprises the following steps: pre-processing livestock excretion and mixing oxalic acid dehydrate with the excretion inside a heavy metal removal device; removing the oxalic acid dehydrate and separating livestock excretion sludge; inserting calcium hydroxide to increase the pH; mixing subsidiary materials with the excretion; supplying air for 12 hours a day for 25 days; and aging the mixture.

Description

Method for preparing Echo-Compost using the Pig Slurry removed the heavy metal, and the Product obtained therefrom}

The present invention can remove heavy metals from livestock manure, improve the treatment efficiency and utilization of livestock manure, and at the same time, manufacturing method of environment-friendly compost using livestock manure removed heavy metals that can prevent soil contamination by heavy metals. And it relates to an environmentally-friendly compost prepared therefrom, and in particular to a method for producing environmentally-friendly compost by removing subsidiary heavy metals such as copper, zinc through the oxalic acid dihydrate from livestock manure to add eco-friendly compost and from there.

In general, livestock manure, such as milk powder, pig meal and livestock meal, has the highest total load of biological oxygen demand (BOD) in comparison with various industrial wastewaters and high water pollution load compared to the generation amount. Therefore, when the livestock manure is discharged as it is, the water quality of the river is deteriorated, the groundwater is contaminated, it causes eutrophication, contaminates water supply and agricultural water, and causes odors and pests to harm the pleasant living environment.

 Korean Patent No. 10-0371823 discloses a method and material for separating heavy metals from substrates such as contaminated soil, sludge, sediments and industrial residues, but after removing heavy metals by applying livestock manure, manure is used as fertilizer. Recycling requires more research and development.

In addition, the Republic of Korea Patent No. 856063 discloses a method for manufacturing a high quality organic material by electron beam and gamma irradiation to remove harmful heavy metals of livestock manure, but this method alone is an efficient method for removing heavy metals and recycling waste resources This has not been done.

Recently, many studies on methods and techniques for treating livestock manure have been conducted, and one method of using livestock manure for crop cultivation is known. However, if the livestock manure is used to cultivate crops without proper treatment, ammonia gas, etc. is generated to inhibit the growth of crops, and heavy metal contamination and accumulation impedes the growth of crops. There is a problem.

As is commonly known, compost is a fertilizer (or manure) produced primarily by mixing fertilized rice with straw or weeds and leaves, followed by fermentation.

On the other hand, compost is popularized to manufacture using such raw materials, but in recent years it is known to be produced using a sawdust that functions as a manure and food waste and moisture control agent of livestock.

As mentioned above, compost is preferred as a means for cultivating agricultural products by organic methods without contaminating soil, and various raw materials are proposed, but the most important point is that the compost does not contaminate soil secondaryly. It should give an excellent effect on its function as a fertilizer to nourish agricultural products.

On the other hand, the most recently developed and commonly used method of the compost manufacturing method as described above, if the livestock manure produced in the livestock farms are discarded in the mountain stream, the soil and rivers seriously pollute the livestock manure and moisture control agent A method of producing compost by mixing and fermenting sawdust or the like, which functions as a function, has been proposed.

Republic of Korea Patent No. 466363 discloses a method for producing compost by using chaff instead of sawdust, but this is merely a non-measurement, not to change the chemical composition of the pig sludge.

The livestock manure contains high concentrations of nitrogen, phosphorus and potassium, which are necessary for plant growth, making it useful as a fertilizer resource, while heavy metals such as copper and zinc supplied through livestock feed far exceed the standard. As a result, the qualitative decline of livestock manure resources has been an obstacle to the resourceization of livestock manure.

As described above, as a result of the review of the prior art, there is no technology and method for efficiently controlling harmful heavy metals that can be derived in connection with the utilization of livestock manure as an excellent organic resource as the object of the present invention. .

On the other hand, it is scheduled to be ocean dumping of livestock waste is banned from 2011 and 2005 Marine tugiryang of reference livestock manure 2,745,000 was 17% increase compared to 2004 m ³ bags, full ocean dumping quantities of livestock Manure accounts for nearly 30%. The amount of the existing composting process with throughput of about 7,600m ³ per day level are expected to be a limit to handle a large amount of technology that lowers the content of compost or less to remove the heavy metals in the future livestock manure or reference values are urgently required .

Therefore, the present invention was made to solve the problems that occurred during the manufacturing process of compost by using livestock manure as in the prior art, the object of the present invention by using oxalic acid dihydrate to remove the heavy metal contained in the livestock manure after composting To provide a manufacturing method of environmentally-friendly compost using livestock manure from which heavy metals are removed, and environmentally-friendly compost prepared therefrom.

Another object of the present invention is to prepare a method for producing environmentally friendly compost using livestock manure removed from heavy metals that can prevent the cause of the natural environment pollution in order to improve the efficiency and utilization of livestock manure and environmentally friendly compost manufactured therefrom To provide.

Still another object of the present invention is to provide a method for preparing environmentally friendly compost using livestock manure removed from heavy metals, which can prevent soil contamination by heavy metals by preparing compost from which heavy metals are removed, and environmentally friendly compost prepared therefrom.

The present invention has been made to achieve the above object, the manufacturing method of environmentally-friendly compost using livestock manure removed heavy metals of the present invention in the manufacturing method of environmentally-friendly compost using livestock manure, (1) pre-treatment by collecting livestock manure A first step of mixing and treating with an aqueous solution of oxalic acid dihydrate in a heavy metal removal device; (2) a second step of separating the livestock manure sludge after removing the oxalic acid dihydrate aqueous solution containing copper and zinc from the mixture; (3) a third step of adding slaked lime to the separated livestock manure sludge to increase the pH; (4) a fourth step of adding a subsidiary material to the livestock manure to which slaked lime is added and then mixing; (5) a fifth step of supplying a blowing air to the mixture of the fourth step in a stirring equipment for 12 hours a day and inverting once a day for 5 days to ferment for 25 days; And (6) characterized in that it comprises a sixth step of blowing air only for one week.

Here, livestock manure includes dung and urine excreted by livestock such as cattle, pigs, and chickens. The organic acid treated to remove copper and zinc is oxalic acid dihydrate (C ₂ H ₂ O _{4 ??} 2H ₂ O). The subsidiary material is preferably mixed with at least one selected from the group consisting of bark, sawdust, fallen leaves, rice husk, rice straw, weeds and the like.

In the manufacturing method of environmentally friendly compost using livestock manure from which the heavy metals of the present invention are removed, preferably, the first step includes (1) 1-10% (w / v) livestock manure in an aqueous solution of oxalic acid dihydrate in the heavy metal removal device. Mixing; And (2) precipitating the mixture for 10 hours, followed by shaking for 20 to 25 hours at a constant speed of 50 rpm.

Here, the use of livestock manure at 1% (w / v) or less is expensive, and when used at 10% (w / v) or more, the removal rate of copper and zinc is lowered.

The method for producing environmentally friendly compost using livestock manure from which the heavy metal of the present invention is removed is more preferably characterized in that the aqueous solution of oxalic acid dihydrate is mixed with 2.25 to 9.0% (w / v) oxalic acid dihydrate.

In this case, when the oxalic acid dihydrate is used at 2.25% (w / v) or less, the removal rate of copper and zinc is reduced, and when used at 9.0% (w / v) or more, it is difficult to dissolve in water.

The manufacturing method of environmentally friendly compost using livestock manure from which the heavy metals of the present invention are removed is more preferably. The second step (1) passes through the mixed solution through a 0.5 mm sieve in a heavy metal removal device and then uses copper and zinc to filter. Separating the contained aqueous oxalic acid dihydrate solution; And (2) characterized in that it comprises the step of separating the livestock waste sludge separated in the step (1) to the collection tank (30).

The method for producing environmentally friendly compost using livestock manure from which the heavy metals of the present invention are removed is more preferably characterized in that the third step adds 98.5 to 96.5 wt% of livestock manure sludge and 1.5 to 5 wt% of slaked lime.

Here, when the slaked lime is 1.5 wt% or less, the pH is too low, and when it is 5 wt% or more, the pH is too high.

In the manufacturing method of environmentally friendly compost using livestock manure from which heavy metals of the present invention are removed, most preferably, by adding 60 to 40% by weight of an auxiliary material to 40 to 60% by weight of a mixture of slaked lime to livestock manure sludge separated in a stirred facility. It is characterized in that the composting process.

In addition, the environment-friendly compost using livestock manure removed heavy metal of the present invention is characterized in that produced by the manufacturing method of environmentally friendly compost using livestock manure removed the heavy metal.

According to the manufacturing method of environmentally friendly compost using livestock manure which removes heavy metal of the present invention, it is possible to remove heavy metals from livestock manure using oxalic acid dihydrate, and to use less amount of auxiliary materials than conventional compost manufacturing method In addition to improving the efficiency and utilization of manure, there is an effect that can prevent soil contamination by heavy metals.

The heavy metals contained in the pig meal were removed by adding an aqueous solution of oxalic acid dihydrate using an apparatus for removing heavy metals contained in the pig meal filed by the applicant.

Figure 1 is a longitudinal sectional view schematically showing a heavy metal removal device for removing heavy metals contained in the pig meal of the present invention, Figure 2 is a schematic diagram showing a process for producing the compost of the present invention.

Before describing the compost manufacturing process and embodiments of the present invention, the configuration and operation of the heavy metal removing apparatus of FIG. 1 used in the present invention will be described first.

As shown in FIG. 1, the heavy metal removing device 100 includes an upper cover 11a covering an inlet (not shown) for injecting money from which foreign matter such as wood or vinyl is removed, and having a particle size of 0.5 mm at the bottom thereof. Reservoir 11 and a storage tank 13 provided with a lower cover 12a for covering a lower opening (not shown) for removing foreign matter (for example, straw, tree branches, etc.) contained in the above pig meal. A pump 15 in which an introduction pipe 15a is connected to the storage tank 13 and a discharge pipe 15b is connected to the reactor 11 so as to supply an aqueous oxalic acid dihydrate solution into the reactor 11. And a siege heater 17 wound and installed on the inner circumferential surface of the reactor 11 to radiate heat when the power is applied, and to stir the pig meal and the organic acid solution supplied into the reactor 11. In the center of the reactor (11) A stirrer 19 including a plurality of agitating blades 19b provided at a predetermined interval on the outer circumferential surface of the shaft 19a and having a shaft 19a mounted thereon, and an upper portion of the shaft 19a of the stirrer 19. A geared motor 21 for rotating the stirrer 19 when the power is applied, and 0.5 contained in the pig meal at the time of opening the first valve 23 at a predetermined distance from a lower portion of the stirrer 19. Sieve made of stainless steel (25 sieve) formed with a plurality of holes of 0.5 mm to filter foreign substances larger than mm, oxalic acid dihydrate containing 0.5 mm or less of pig meal and copper and zinc that passed through the screening network (25) The first valve 27 installed in the bottom of the sorting network 25 to control the discharge of the aqueous solution, 0.5 mm or less of pig powder and copper and zinc discharged to the lower passage 28 of the first valve 27 Oxalate containing copper and zinc in aqueous oxalic acid dihydrate solution The filtration filter 29 extracting the dihydrate aqueous solution and the oxalic acid dihydrate aqueous solution containing copper and zinc filtered by the filtration filter 29 were discharged to the copper / zinc-containing oxalic acid dihydrate aqueous solution collection tank 30. The particle size of the second valve 31 provided in the first pipe 28a connected to the lower passage 28 and the copper / zinc-containing oxalic acid dihydrate solution extracted from the lower passage 28 was 0.5 mm to control the intermittence. It consists of the 3rd valve 33 provided in the 2nd piping 28b connected to the said lower channel 28 so that the following pig meals may be discharge | released to the pig meal collection tank 32. As shown in FIG.

The introduction pipe 15a connected to the pump 15 is provided with a meter 16a so as to display the supply amount of the aqueous solution of oxalic acid dihydrate supplied into the reactor 11, and also the oxalic acid supplied into the reactor 11. The valve 16b which cuts off supply of aqueous dihydrate solution is provided.

In the drawing, reference numeral 11b is a handle installed on the upper cover 11a to open and close the upper cover 11a, and 11c is installed on the upper portion of the reactor 11 so that the vapor pressure in the reactor 11 is constant. When the pressure is higher than the pressure, the steam pressure in the reaction tank 11 is discharged to the atmosphere, and when the steam pressure in the reaction tank 11 is lower than the predetermined pressure, the safety valve is closed, and 12b is to open and close the lower cover 12a. The handle is installed on the lower cover 12a, 21a is a power line for supplying power to the geared motor 21, 27a is a handle for opening or closing the first valve 27, 25a is the lower passage A handle for vertically positioning the screening net 25 with respect to the cross section of 28, 31a is a handle for opening or closing the second valve 31, and 33a for opening or closing the third valve 33; Occlusion handle The.

Next, the operation of the heavy metal removing device made as described above will be described.

First, after holding the handle (11b) provided on the upper cover (11a) covering the upper opening of the reaction tank 11, opening the upper cover (11a), injecting money into the reactor 11, and then the upper cover ( Close 11a).

Next, after setting the discharge amount of the aqueous solution of oxalic acid dihydrate to be supplied into the reactor 11 to the meter 16a, the valve 16b is opened and the power is supplied to the pump 15 from a control panel not shown. When the pump 15 is driven, the aqueous solution of oxalic acid dihydrate stored in the storage tank 13 is sucked through the inlet pipe 15a to allow the valve 16b, the meter 16a, and the discharge pipe 15b. Through this, the discharge amount of the oxalic acid dihydrate aqueous solution set by the meter 16a is supplied into the reactor 11.

When the discharge amount of the aqueous solution of oxalic acid dihydrate set by the meter 16a is supplied into the reactor 11, the valve 16b is closed, and then the siege heater 17 is not connected to the control panel. When power is applied and power is applied to the geared motor 21, the siege heater 17 is shaken for 20 to 25 hours while radiating heat of 40 degrees Celsius to 50 degrees Celsius, and at the same time, the stirrer 19 As the gyro turns, the toxin powder and the oxalic acid dihydrate solution mixed in the reactor 11 are mixed, and the heavy metals contained in the toxin powder, ie, copper (Cu) and zinc (Zn), are adsorbed to the oxalic acid dihydrate solution.

After copper (Cu) and zinc (Zn) are adsorbed on the oxalic acid dihydrate solution, the handle 25a is turned to 90 °. By turning to position the sorting network 25 perpendicular to the cross section of the lower passage 28, and opening the first valve 27 installed in the lower passage 28, the sorting network 25 and the first An aqueous solution of oxalic acid dihydrate containing pig meal and copper / zinc is dropped into the lower passage 28 through one valve 27, and an aqueous solution of oxalic acid dihydrate containing copper and zinc is extracted from the filtration filter 29. Copper and zinc-containing oxalic acid dihydrate solution extracted from the filtration filter 29 is rotated by holding the handle 33a of the second valve 31 installed in the first pipe 28a to rotate the second valve 31. After discharging to the copper / zinc-containing oxalic acid dihydrate aqueous solution collection tank 30, and when the discharge of the copper and zinc-containing oxalic acid dihydrate solution is completed, the second valve 31 is closed.

Next, the copper and zinc removed from the lower passage 28 are removed and rotated by holding the handle 33a of the third valve 33 installed in the second pipe 28b to rotate the third valve 33. It is opened and discharged to the pig powder collection tank 32, and after all the pig powder is discharged, the said 1st valve 27 and the 3rd valve 33 are closed.

The copper and zinc-containing oxalic acid dihydrate solution collected in the copper / zinc-containing oxalic acid dihydrate aqueous solution collection tank 30 is transferred to a wastewater treatment apparatus (not shown) to extract copper and zinc, and the pig powder collection tank 32 The collected money in) is transferred to a compost manufacturing device (not shown).

The exothermic temperature of the siege heater 17 can of course vary from 30 degrees Celsius to 60 degrees Celsius.

On the other hand, in order to remove the foreign matter contained in the 0.5 mm or more pig powder sludge filtered on the upper portion of the sorting net 25, by holding the handle 12b installed on the lower cover 12a by opening the lower cover 12a After removing through the lower opening (not shown) of the reactor 11, the lower cover 12a may be covered.

In the above description, when the vapor pressure in the reaction tank 11 is higher than or equal to a predetermined level by heat radiation to the siege heater 17 provided on the inner circumferential surface of the reaction tank 11, the safety valve 11c is opened to open the reaction tank 11. The safety valve 11c is closed when the vapor pressure in the reaction tank 11 becomes less than a predetermined pressure as the vapor pressure in the reactor is discharged to the atmosphere and the vapor pressure in the reactor 11 is discharged to the atmosphere.

Below is the result of heavy metal removal using oxalic acid dihydrate solution.

Various organic acids were added to distilled water as shown in Table 1 below and shaken for 2 hours to completely dissolve them.

Table 1 Preparation of Aqueous Oxalic Acid Dihydrate Solution

5% (w / v) of pig meal was added to a Erlenmeyer flask in an organic acid aqueous solution prepared as shown in Table 1, shaken with a shaker for 24 hours, separated from the organic acid with a filter paper, and dried for 24 hours in a hearth. After drying again at 50 ° C. for 24 hours in a drier, the contents of copper and zinc were measured by atomic absorption spectrometry.

Removal rates of copper and zinc for each organic acid are shown in Tables 2 and 3 below.

TABLE 2 Copper Removal Rate of Samples from Organic Acids

TABLE 3 Zinc removal rate of sample from organic acid

In terms of copper removal rate, oxalic acid dihydrate shows 54% removal rate and in terms of zinc removal rate, citric acid has the highest removal rate of 97%.

An aqueous solution of oxalic acid dihydrate was prepared at four levels by adding 2.25, 4.5, 6.75, and 9.0% (w / v) to the aqueous solution of oxalic acid dihydrate. The oxalic acid dihydrate was selected as the most suitable organic acid in consideration of the input ratio of organic acid and the removal rate of heavy metal by removing heavy metals as described above again with the selected four levels of aqueous oxalic acid dihydrate solutions.

1 to 10% (w / v) of pig flour was mixed with aqueous solution of oxalic acid dihydrate, placed in heavy metal removal system, and settled for 10 hours, set as timer for 10 minutes at 1 hour, and then shaken at 50 rpm for 20 hours. After repeated, after passing through a 0.5 mm sieve, an aqueous oxalic acid dihydrate solution containing copper and zinc was separated using a filtration filter.

Table 4 Removal Rate of Copper and Zinc in Oxalic Acid Dihydrate Aqueous Solution by Level

[Table 5] Addition ratio of slaked lime

As shown in Table 5, even when only 1.5 wt% of the slaked lime is mixed, the pH change is large, but even if 5 wt% or more is mixed, the change in pH is small. Judging by the percentage, the subsidiary materials were mixed to proceed with the composting process.

Hereinafter, a method for preparing compost using livestock manure from which heavy metals are removed according to a preferred embodiment of the present invention, and environmentally friendly compost using livestock manure from which heavy metals are removed therefrom will be described in detail with reference to the accompanying drawings.

Example

Method for producing a compost of the present invention as shown in Figure 2 as follows.

1. Heavy Metal Removal (Step 1)

How to remove heavy metals of pig powder will be described with reference to FIG.

(1) collection of money

In February 2008, about 200kg was collected from a don distribution in Seokmun-myeon, Dangjin-gun, Chungnam. In order to ensure accuracy, samples were taken three times and mixed at the same place at weekly intervals.

(2) pretreatment of money

The collected pig meal was naturally dried for about three days in the pretreatment chamber, and then filtered through a sieve of 3 to 5 mm to remove foreign matter such as wood and vinyl.

(3) Mixing Pig Flour and Aqueous Oxalic Acid Dihydrate Solution

In the heavy metal removal device, the pig powder and the previously prepared aqueous oxalic acid dihydrate solution are mixed.

(4) precipitation and shaking

The mixed solution of the pig flour and the aqueous solution of oxalic acid dihydrate is precipitated for 10 hours and then shaken for 20 to 25 hours at a speed of 50 rpm for 10 minutes each hour.

2. Removal of aqueous solution of oxalic acid dihydrate (2nd step)

(1) Separation of Aqueous Oxalic Acid Dihydrate Solution

After passing the mixed solution of the pig powder and the aqueous solution of oxalic acid dihydrate through a 0.5 mm sieve, an aqueous solution of oxalic acid dihydrate containing copper and zinc is separated using a filter.

3. Addition of pig flour sludge and slaked lime (3rd process)

Slaked lime is added to raise the pH of pig flour sludge. Pig manure itself is suitable as fertilizer with pH of about 7 neutral level, but even though sludge sludge that removes heavy metals with organic acid is low organic acid, its pH drops rapidly to below 2.0 level after contact with acidic solution. This is because the chemical properties have changed in the process of being precipitated in the organic acid for more than 48 hours. In order to be used as a fertilizer used in agriculture, it must be adjusted to an appropriate pH. In order to adjust the pH level, the hydrated lime was mixed in a proportion to observe the change in pH.

4. Addition and mixing of subsidiary materials (4th step)

 40 to 60% by weight of pig flour sludge and 60 to 40% by weight of subsidiary materials are mixed. Preferably, 40 to 60% by weight of livestock manure sludge treated in the third step and 60 to 40% by weight of an auxiliary material including at least one bark, sawdust, deciduous leaf, rice hull, rice straw, and weeds are composted in a stirred facility. Proceed.

The composting process was carried out by injecting 3 to 3㎥ of Examples 1 to 3 into a stirred plant of an organic fertilizer production plant in Dangjin-gun, Chungnam, Korea. Twelve hours were supplied and the inversion was performed once daily.

5. Fermentation (5th process)

In a stirred system, the mixture is blown with air for 12 hours per day, and inverted once a day for fermentation for 25 days.

6. After-staying (6th process)

Only the air is blown into the fermented mixture for one week to ripen.

Seedling Test

A series of processes for producing pig flour sludge in a composting facility is called composting or housing. This process is important because if you fertilize the organic materials containing pig powder sludge or organic matter to the crop without any treatment, a large amount of unsaturated material is decomposed by the microorganisms and the temperature rises in this process. This can lead to a drastic change in chemical properties, resulting in phenomena compared to crops, which can eventually lead to the death of crops (Riffaldi et al., 1986; Sugahara et al., 1984). For this reason, from January 2009, regulations have been established by establishing a process standard called maturity in the process standard for by-product fertilizers.

Various methods are available to evaluate plant stability to date, but there are limitations due to the characteristics and disadvantages of the raw materials applicable to each assay, so it will not be possible to establish accurate criteria for which assay is the most accurate.

For this reason, in order to evaluate the stability of recyclable fertilizers, it is judged that the seedling assay for direct planting has the simplest and highest reliability. Therefore, six species of alfalfa, crimson clover, hairy beach, corn, self-run and orchardgrass are used. To prepare a fertilizer sludge sludge sludge sludge sludge sludge sludge sludge was added to the composting process was added to the proportion of the fertilizer produced in 20 to 20% proportional to the volume of the fertilizer sludge produced.

The soil was collected from the fermented acid and screened using a 5 mm sieve, and then heated to a temperature of 90 ° C. to disinfect the bacteria, thereby preparing a cultured soil. Six feeds of Young, Orchardgrass, Crimson Clover, Hairy Beach, Corn, and Alpha Wave after four treatment levels were prepared, which were mixed 20% in proportion to the volume of the pot container to be used. Germination rates and average number of germination days were investigated after seeding each 10 hole into 32 hole pot. When germination was completed, watering was carried out twice a day in the plant growth system.

The fresh weight was measured 10 days after sowing, and the dry weight was measured after drying at 70 ° C. for 3 days.

The fertilizer control law is commensurate with the process standards of the compost. When the content of copper and zinc in the sample is caught more than the process standard, it is administratively punished and this part is emerging in recent years.

Example 1

An oxalic acid dihydrate solution was mixed with 40% by weight of pig flour sludge from which copper and zinc were removed and 60% by weight of bark to produce a fertilizer.

Example 2

The oxidized fertilizer was produced by mixing 50% by weight of pig flour sludge and 50% by weight of bark sludge removed with copper and zinc with an aqueous solution of oxalic acid dihydrate.

Example 3

The oxidized fertilizer was produced by mixing 60% by weight of pig flour sludge removed with copper and zinc and 40% by weight of bark with an aqueous oxalic acid dihydrate solution.

Comparative example

Products that meet the process standards of by-product fertilizer compost in the market were purchased from agricultural materials retailer in Dangjin-gun, Chungnam.

[Table 6] Physicochemical Properties of Composts According to Comparative Examples and Examples

As shown in Table 6, the contents of nitrogen and phosphoric acid were 4.44% and 6.29% in the case of pig flour sludge, and the total carbon content was 67.81%, which can be judged to be highly utilized in terms of fertilizer, but the content of copper and zinc is 787 mg / kg. It is 1850 mg / kg, higher than the standard 300 mg / kg and 900 mg / kg. Composts of Examples 1 to 3 prepared by the present invention satisfies all of the standard, there will be no shortage even when comparing the comparative example and the components. Therefore, as a problem of the comparative example, by simply mixing and diluting only the subsidiary materials with swine sludge, the soil and environmental pollution cannot be solved fundamentally, and environmental problems such as forest damage caused by consuming a large amount of subsidiary materials could not be solved. It can be seen that Examples 1 to 3 according to the present invention solve the above-mentioned fundamental problem by removing copper and zinc using oxalic acid dihydrate.

 In relation to the effect measurement, the germination capacity was measured in the compost of Comparative Examples and Examples 1 to 3 are shown in Table 7.

[Table 7] Germination capacity measurement

a: alfalfa, s: self-operated, o: orchardgrass, r: crimson clover, h: hairre beach, c: corn

As shown in Table 8, Comparative Examples and Examples 1 to 3 show similar germination rates and thus did not show a significant difference.

The crops germinated in the compost of Comparative Examples and Examples 1 to 3 were put in a crop growth system and grown for a week, and the growth thereof was measured as shown in Table 8 below.

[Table 8] Growth Measurement

As shown in Table 8, the growth of Examples 1 to 3 was not statistically significant compared to the comparative example.

The germination rate and initial growth characteristics of six silage crops were investigated. In terms of germination rate, the fertilizer made from pig flour sludge has low germination capacity due to high EC level, but it is effective in growing crops. Composts of Examples 1 to 3, in which copper and zinc of pig flour sludge were removed with a dihydrate, were not statistically compared with the comparative examples.

As can be seen through the examples and comparative examples of the present invention, in the case of manufacturing compost after removing heavy metals by adding oxalic acid dihydrate to pig flour sludge according to the present invention, the amount of auxiliary materials is higher than that of the conventional compost manufacturing method. By using less, it is expected to improve the efficiency and utilization of pig sludge as well as to prevent soil contamination by heavy metals.

The above description is merely illustrative of the technical spirit of the present patent, and those skilled in the art to which the present patent belongs may make various modifications and changes without departing from the essential characteristics of the present patent.

In addition, the embodiments disclosed in the present patent are not intended to limit the technical spirit of the present patent but to describe the technical spirit of the present patent.

Therefore, the protection scope of the present patent should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto shall be construed as being included in the scope of the patent.

The present invention can be used for the cultivation of crops by providing a method for producing compost from pig flour sludge removed heavy metals.

1 is a longitudinal sectional view schematically showing a heavy metal removal device for removing heavy metals contained in livestock manure of the present invention

Figure 2 is a schematic diagram showing a process for producing environmentally friendly compost using livestock manure removed heavy metals of the present invention.

Claims (8)

A method for producing environmentally friendly compost using livestock manure, comprising: (1) a first step of collecting and pretreating livestock manure and mixing and treating it with an aqueous solution of oxalic acid dihydrate in a heavy metal removal device; (2) a second step of separating the livestock manure sludge after removing the oxalic acid dihydrate aqueous solution containing copper and zinc from the mixture; (3) a third step of adding slaked lime to the separated livestock manure sludge to increase the pH; (4) a fourth step of adding a subsidiary material to the livestock manure to which slaked lime is added and then mixing; (5) a fifth step of supplying a blowing air to the mixture of the fourth step in a stirring equipment for 12 hours a day and inverting once a day for 5 days to ferment for 25 days; And (6) a method for producing environmentally friendly compost using livestock manure from which heavy metals have been removed, comprising a sixth process of blowing air only for one week to ripen. The method according to claim 1, wherein the first step comprises the steps of: (1) mixing the livestock manure with an aqueous solution of oxalic acid dihydrate in a heavy metal removal device at 1 to 10% (w / v); And (2) precipitating the mixed solution for 10 hours, and then shaking the mixture for 20 to 25 hours at a constant speed of 50 rpm. The method of claim 2, wherein the aqueous oxalic acid dihydrate solution is mixed with 2.25% to 9.0% (w / v) oxalic acid dihydrate. 2. The method of claim 1, wherein the second step comprises the steps of: (1) passing the mixed solution through a 0.5 mm sieve in a heavy metal removal apparatus and separating an aqueous solution of oxalic acid dihydrate containing copper and zinc using a filtration filter; And (2) discharging the livestock manure sludge separated in step (1) to the collection tank 30, wherein the method for producing environmentally friendly compost using livestock manure from which heavy metals have been removed. The method of claim 1, wherein the third step comprises 98.5 to 96.5% by weight of livestock manure sludge and 1.5 to 5% by weight of calcined lime. According to claim 1, wherein the fourth step is 60 to 40% by weight of the subsidiary material containing at least one bark, sawdust, fallen leaves, rice husk, rice straw, weeds in 40 to 60% by weight of livestock waste sludge treated in the third step Method for producing environmentally friendly compost using livestock manure removed heavy metals, characterized in that the composting process in a stirred facility by adding. The method of claim 1, wherein the fourth step is agitated by adding 50% by weight of an auxiliary material including at least one bark, sawdust, fallen leaves, rice husk, rice straw, and weeds to 50% by weight of livestock manure sludge treated in the third step. Eco-friendly compost manufacturing method using livestock manure removed heavy metal, characterized in that the composting process in progress. An environmentally friendly compost using livestock manure from which heavy metals prepared by any one of claims 1 to 7 are removed.

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