KR20010069877A - Method for treating organic waste material - Google Patents

Abstract

PURPOSE: Disclosed is a method for treating organic waste to produce high-quality compost with high CEC(Cation Exchange Capacity) and humification grade using alkaline earth metal mineral powder, inorganic acid, bulking agent etc. CONSTITUTION: The method for treating organic waste is characterized by injecting mineral powder containing alkaline earth metal, plastic powder thereof, dried organic matter like peat, sawdust, rice hulls as bulking agent into organic waste like food garbage, livestock excretions, agricultural and marine products waste, sewage and wastewater sludge, slaughter place waste, food processing factory waste; neutralizing to the pH7 by providing inorganic acid like sulfuric acid, nitric acid, hydrogen chloride as stirring in the blender(6) with blender-stirrer(7); maturing in maturity tank(11).

Description

Method for treating organic waste material

The present invention relates to organic waste such as food waste, livestock manure, agricultural and marine waste, sewage and waste sludge, slaughterhouse waste, food processing plant waste, and the like, alkaline earth metal mineral powder, inorganic acid, swelling agent ( The present invention relates to a treatment method for producing high quality compost which is economical and hygienic using a bulking agent).

Most of the organic wastes mentioned above have a high water content, and especially in summer, they are easily decayed and decayed and generate a bad smell. In addition, pests such as flies and rats live there is a hygienic problem.

In the past, only a few of these organic wastes were composted and fed into the landfill, and most of them were disposed of in landfills. This was determined.

Thus, a separate disposal problem of organic waste has arisen. As the treatment method, composting, feed, anaerobic digestion, methane gas generation, incineration, sewage combined treatment, etc. were discussed.

However, energy, incineration, and sewage combined treatment due to methane gas generation due to anaerobic digestion are not resourceized at all, and the treatment cost is high, and there is a problem that is hardly realized. In particular, in the case of food waste, the concentration of unsaturated fatty acids in liquids such as cooking oil is high, and energy generation by methane gas generation by anaerobic digestion, and sludge, which is a microbial cell, agglomerate over time in the case of combined wastewater and wastewater treatment. This makes the processing impossible. In the case of feed, the feed cost was reduced, so it was fed to cattle, pigs, ducks, chickens, etc., but cattle could cause mad cow disease and foot-and-mouth disease. It is expected that breeding will be banned because it can cause it. In addition, ducks and chickens are also being avoided by various livestock farms due to high mortality caused by viral pathogens.

Organic wastes with high moisture content such as food waste and livestock manure are used as swelling agents (moisture regulators), but sawdust and rice husk are used, but the purchase price is high and there is no economic feasibility. It was.

In addition, in the case of food waste, the concentration of salt (NaCl) is high, so it is not possible to use it as compost because the salting phenomenon of crops and the grain structure of soil are isolated and soiled.

In order to reduce the cost and odor occurrence of the swelling agent as described above, the Republic of Korea Patent Publication No. 1997-010709, 1998-048486, 1999-046522, 1999-069483, 2000-030257, In 2000-033746, quick lime, hydrated lime and dolomite are injected into organic wastes with high moisture content such as food waste and livestock manure and heated to high temperatures of 60 to 100 ° C by reaction heat generated during water and hydrolysis. Causes most of the microbes in the waste to die. In addition, powders such as quicklime, slaked lime, and dolomite are excellent in adsorption of malodor-causing substances, resulting in almost no odor. Thus, it was determined that high quality compost is produced in a short time, but there are problems as follows, which are not commercialized.

First, in the case of food waste having a water content of 82 to 85 wt% and 25 ° C., injecting quicklime to raise the temperature to 100 ° C. by hydrolysis reaction heat requires that more than 50 parts of quicklime be infused into 100 parts of food waste. Since it becomes 25% or less, another organic submaterial must be mixed.

Second, quicklime or dolomite can become hydrated lime when hydrolyzed with water, so that no microorganism can grow because the pH becomes a strong alkaline substance with a buffer zone of 12 or more. Therefore, the organic organic matter does not occur at all in the maturation process is present in the organic matter state when fertilizing aerobic microbial growth is active when the crop is reduced by reducing the oxygen concentration of the soil can not be composted because the crop is depleted.

Third, no plants can grow in a strong alkaline state with a pH of 9-10 or more. As described above, when organic wastes are treated with quicklime or dolomite, they cannot be fertilized in large quantities because they have a pH of 12 or more.

Fourth, the mineral intake of microorganisms as well as plants can be easily absorbed in the form of complex salts with chelate organic acids such as citric acid, tartaric acid, humic acid, fulvic acid and the like. In the composting process, chelating organic minerals are formed by the generation of humic substances such as humic acid and fulvic acid. Therefore, since it exists as a pure mineral, absorption efficiency of essential minerals such as calcium, potassium, zinc, magnesium, etc. is inferior.

The present invention solves the above problems and in order to produce high quality and safe and safe compost, alkaline earth metal minerals such as calcium carbonate (CaCO ₃ ), magnesium carbonate (MgCO ₃ ), or calcined powder thereof After mixing and stirring (CaO), magnesium oxide (MgO) and the like, and supplying inorganic acids such as sulfuric acid (H ₂ SO ₄ ), hydrogen chloride (HCl), and nitric acid (HNO ₃ ) to adjust the pH to around 7 by neutralization reaction heat. After evaporating a considerable amount of water above 100 ℃, killing the seeds of weeds as well as harmful microorganisms such as pathogenic microorganisms, decayed and perishable microorganisms, and then mixing appropriate amounts of swelling agents such as peat, sawdust and chaff, and then transporting them The purpose is to produce high-quality fertilizers in a short time by mesophilic corrosive microorganisms, omitting the high temperature fermentation process.

Organic wastes are particularly hygienic because they easily rot and deteriorate in summer, causing severe odors, flies, and rats. In addition, food waste, livestock manure, etc., because the water content is high, the consumption of the swelling agent is large, it takes two to three times the processing cost of the compost sales cost, there is no economical.

The present invention treats organic wastes with high moisture content such as food waste and livestock manure at less than half the cost of compost sales, while improving the economics, while suppressing the odor generation and flies such as flies in the processing process to the maximum. Its purpose is to produce high quality compost that is rich in chelating organic minerals and has a high Cation Exchange Capacity (CEC) and a high degree of corrosion.

1 is a schematic process flow chart for composting organic wastes such as food waste, livestock manure, agricultural and marine waste, sewage and waste sludge, slaughterhouse waste, and food processing plant waste.

[Explanation of symbols on the main parts of the drawings]

1: reservoir 2: reservoir stirrer

3: transfer pump 4: desalination unit

5: rectifier 6: admixture

7: Admixture Agitator 8: Transfer Belt Conveyor

9: suction blower 10: exhaust blower

11: Housing 12: Rotary Mixer

In order to achieve the above object, the following description will be given based on the drawings.

The part which shows the quantity of the preparation used below means a weight part.

When organic waste is brought into the composting plant, vinyl bags and large foreign matters are first separated and removed, and then crushed by a crusher, and then stored in an organic waste storage tank 1 and stored in an organic waste storage tank 1 by a stirrer 2. Is homogenized.

When the organic waste of the storage tank 1 is transferred to the blender 6 by the transfer pump 3, the organic waste having a high salt content, such as food waste, is already developed by the desalination apparatus of Korean Patent Laid-Open Publication No. 2000-0470080 ( After desalting by 4), a certain amount is injected into the mixer 6, and an organic waste having a low salt content is directly injected into the mixer 6 in a certain amount.

Next, the swelling agent, such as sawdust, rice husk, peat, and foliar soil, is injected into 100 parts of organic waste, and is stirred with the admixture stirrer 7. Next, about 10-30 parts of alkaline earth metal mineral powder or the calcined powder is injected.

In this case, when a large amount of calcium oxide (CaO) component is contained in the calcined alkaline earth metal, the temperature rises due to hydrolysis reaction with water.

CaO (s) + H ₂ O (l) → Ca (OH) ₂ (s) ΔH _{25 ° C} = 15.583 Kcal / g.mol

Next, inorganic acids such as sulfuric acid, hydrogen chloride, and nitric acid are injected to adjust the pH to around 7 which is neutral. At this time, a considerable amount of water evaporates as the temperature rises above 100 ° C by reaction with alkaline earth metal. When alkaline earth metal and sulfuric acid react, standard heat of reaction is as follows.

Ca (OH) ₂ (s) + H ₂ SO ₄ (s) → CaSO ₄ (s) + 2H ₂ O (l) ΔH _{25 ° C} = 49.3 Kcal / g.mol

CaCO ₃ (s) + H ₂ SO ₄ (s) → CaSO ₄ (s) + C0 ₂ (g) + H ₂ O (l) ΔH _{25 ° C} = 22.4 Kcal / g.mol

MgCO ₃ (s) + H ₂ SO ₄ (s) → MgSO ₄ (s) + C0 ₂ (g) + H ₂ O (l) ΔH _{25 ° C} = 8.0Kcal / g.mol

By reaction heat as mentioned above, it reacts at 90-100 degreeC for about 2 hours, and harmful pathogenic microorganisms, weed seeds, etc. are killed.

As described above, the high-temperature neutralization treatment in the mixer 6 is discharged to the transfer belt conveyor 8 and transferred to the submersible tank 11. In the housing tank 11, the rotary mixer 12 is inverted repeatedly, supplying oxygen in the air, and then housed in a short period of time by soil-corrosive microorganisms for about 10 to 15 days, then transported to a compost storage warehouse, and then sold. do.

Example 1

When 200 parts of food waste was mixed and stirred with 60 parts of quicklime (CaO), the temperature rose to 60 ° C. after 15 minutes at 21 ° C., and 29 parts of 98% sulfuric acid was injected at 95 to 100 ° C. after adjusting the pH to 7-8. After two hours, the emissions were 255 parts and the water evaporation was 34 parts. As a result of inadequate stirring for about 5 days, the compost component test report is shown in Table 1.

Example 2

When 200 parts of food waste was mixed and agitated 20 parts of quicklime, the temperature was 40 ° C. after 15 minutes at 21 ° C., and when 28 parts of sulfuric acid was injected, the temperature rose to 93 ° C., and the pH was 7.5 and after about 2 hours. As a result of discharging it and stirring for a certain period, the test report table for composting components is shown in Table 1.

Example 3

After mixing 141.7 parts of defoliated soil with 200 parts of desalted food waste and mixing 20 parts of quicklime and stirring for 15 minutes, the temperature rose from 21 ° C to 38 ° C and when 28 parts of sulfuric acid were injected to adjust pH7 to The temperature increased to 100 ℃, and the discharge amount was 261 parts, and the moisture evaporation was about 1.7 parts. As a result of stirring for a certain period of time, the compost component test report is shown in Table 1.

Example 4

After mixing 15 parts of peat with 100 parts of desalted food waste and 100 parts of pig meal, 20 parts of quicklime were mixed and stirred for 15 minutes. The temperature rose from 20 ° C to 38 ° C, and 28 parts of sulfuric acid was added to adjust pH7. When the temperature was raised to 93 ℃, after stirring for about 2 hours and discharged for a certain period of time as a result of the compost component test results are shown in Table 1.

Example 5

100 parts of desalted food waste, 10 parts of peat and 10 parts of sawdust were mixed, and then 20 parts of quicklime were mixed and stirred for 15 minutes. The temperature was increased from 20 ° C to 38 ° C and sulfuric acid was adjusted to pH7. When the parts were injected, the temperature rose to 93 ° C, and after 2 hours of stirring and discharged, after a certain period of stirring, the compost component test results are shown in Table 1.

Example 6

When 100 parts of desalted food waste, 100 parts of pig meal, 10 parts of peat and 10 parts of sawdust were mixed, 10 parts of calcium carbonate (CaCO ₃ ), 5 parts of magnesite, and 5 parts of phosphate showed little change in temperature. As a result of 40 parts injection, the temperature was 80 ° C. and the pH was 6.2 after 30 minutes of stirring. As a result of discharging it and stirring for a certain period, the test report table for composting components is shown in Table 1.

Table 1. Analysis table of compost

division Composting Standards Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Water content - 36 35 34 34 34 32 pH - 8.0 7.6 7.2 7.4 7.5 7.2 Organic matter 25 or more 19.07 28 33.87 31.2 40.2 40.2 C / N ratio 50 or less 11.5 11.0 10.2 10.6 10.8 10.8 NaCl (%) 1 or less 0.53 0.57 0.03 0.04 0.03 0.03 AS (mg / kg) 50 or less Not detected Not detected 0.02 0.04 0.02 0.02 cd (mg / kg) 5 or less 0.29 0.28 0.26 0.29 0.30 0.32 Hg (mg / kg) 2 or less 0.01 0.01 0.01 0.01 0.01 0.01 Pb (mg / kg) 150 or less 0.29 0.28 2.25 1.20 1.56 1.53 Cr (mg / kg) 500 or less 0.26 0.28 1.81 1.80 1.92 1.90

Example 7

As a result of fertilizing the compost produced in Examples 1 to 6 on lettuce, strawberries, and Chinese cabbage, Examples 3 to 6 showed very good growth, and Example 2 was also satisfactory, but Example 1 was slightly inferior in growth rate. It was on the side.

Most organic wastes have high moisture content and used sawdust and rice husk as moisture control and swelling agent. Since the cost of sawdust and rice husk is expensive, it takes two to three times as much as the compost sales cost. In addition, food wastes have high salt concentrations, which can cause crop harm, slowing or even killing.

In addition, the SAR (Sodium Adsorption Ratio) value of the soil is high, so it is replaced with Ca ⁺⁺ and Mg ⁺⁺ of the soil, and the grain structure of the soil is shortened, making it difficult to cultivate because of poor drainage and poor soil supply. do.

In the present invention, it is expected that the treatment cost is less than the compost sales cost, while supplying Ca, Mg, etc., and producing high quality compost while bringing the soil improvement effect of lowering the SAR value. Can be.

Claims (1)

Mineral powder containing alkaline earth metal in organic waste such as food waste, livestock manure, agricultural / aquatic waste, sewage / waste sludge, slaughterhouse waste, food processing plant waste, etc. Injecting the dried organic material and the like, while stirring by the mixer agitator (7) in the mixer 6, supplying inorganic acids such as H ₂ SO ₄ , HNO ₃ , HCl to neutralize to pH 7 to facilitate the smooth ripening in the auxiliary bath (11) A method of treating organic waste, characterized in that to produce compost.