JPH0236297A - Production of soil improving agent utilizing sludge - Google Patents

Abstract

PURPOSE:To obtain a soil improving agent effectively usable in acid or low- nutrient soil and reduce pollution by kneading an organic sludge with an ash, such as boiler ash, while heating and stirring, removing moisture and offensive smell and forming the resultant kneaded mixture into a powdery or granular shape. CONSTITUTION:The objective soil improving agent obtained by mixing (A) an organic sludge generated in food processing factories by an activated sludge method, etc., with (B) an ash, such as municipal waste incineration ash or boiler ash, e.g., at >=150 deg.C, while heating and stirring under atmospheric pressure, evaporating moisture and offensive smell and powdering or granulating the kneaded mixture. Furthermore, the mixture of the components (A) with (B) is alkaline at pH 9-12 and the resultant improving agent is capable of regenerating acidified soil to pH6-7 in which microorganisms become active.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing a soil conditioner, and in particular, to a method for producing a soil conditioner, in particular, a method for producing a soil conditioner, in particular, by using a mixture of sludge and boiler ash, which are pollution sources that were previously treated separately, and implementing treatment measures. This article relates to a method for solving the problem all at once and utilizing it as a soil improvement agent.

(Prior Art) In our daily life, fluid waste and fixed waste are inevitably generated.

Therefore, attempts are routinely made to convert such waste into useful final products and to recycle them.

For example, conventional methods such as natural fermentation, solar drying, artificial drying, incineration, artificial fermentation, lime treatment, etc. are known for treating sludge precipitated in the final stage of treatment using activated sludge methods.

However, the natural fermentation method is a system in which food waste is added to sludge, compressed into the shape of building blocks, and fermented naturally, but natural fermentation requires space and time, and is not necessarily suitable for practical use.

The efficiency of the solar drying method and the artificial drying method is significantly affected by geographical conditions and requires a large area, while the latter has high running costs due to its high moisture content, so both methods have economical problems.

In addition, the incineration method also requires equipment costs for the incineration tank, which inevitably increases running costs.The artificial fermentation method can produce optimal compost by supplying oxygen, adjusting the temperature, and mixing and stirring, but it decomposes within 2 to 3 days. It is not possible to obtain mature or stable compost in time.

Therefore, it is necessary to further perform secondary decomposition of the primary decomposition in the fermenter, and an increase in equipment costs is unavoidable. Furthermore, the lime treatment method is a method in which lime is mixed into sludge and subjected to a heating reaction in a granulation dryer to produce lime-treated fertilizer, but there is a problem with the odor of the product.

Although various attempts have been made to utilize sludge, none of them have been found to be decisive, and no satisfactory method has yet been found.

On the other hand, the final treatment for boiler ash, municipal waste incineration ash, etc. is to add moisture to the boiler ash, municipal waste incineration ash, etc. (hereinafter referred to as fly ash), knead it, prevent dust generation, and then dump it using a humidification treatment method. There is a cement assimilation method in which 10 to 20% by weight of Portland cement and water are added and kneaded, then granulated, blown into a storage tank, dried, and then dumped, but all of these methods are for convenience in dumping. , it has not been fully utilized.

In addition, food scraps such as fish scraps, leftover food, and vegetable scraps can be recycled into feed by drying them under reduced pressure without pouring water, or are pulverized in a reaction agitation tank, and chemicals are added while mixing to make them into granules with a diameter of 2 to 511 mm. It is also used to prevent soil acidification and promote alkalinization by adding material compost or alkaline molecules.

(Problems to be Solved by the Invention) As described above, conventionally, sludge and boiler ash have been treated separately, and attention has been paid to their utilization.

However, none of the above-mentioned methods utilizes sludge and boiler ash at the same time to solve the problem of treating both at once.

Therefore, the inventors of the present invention dealt with the above-mentioned actual situation, and in particular, investigated municipal waste incineration ash, which had been treated in a manner contradictory to the above-mentioned methods.
By mixing boiler ash and organic sludge from food processing factories, we aim to solve the problem of both treatments at once, and also aim to utilize the organic sludge as a soil conditioner by focusing on the organic sludge contained in it. The purpose is to mix ash such as the above-mentioned municipal waste incineration ash and boiler ash with organic sludge precipitated by the activated sludge method in a food processing factory under high vacuum while heating and stirring, and to forcefully evaporate water through vacuum drying to remove odor. We proposed a method to obtain a granular soil conditioner by removing .

However, upon further study of the above method, it was found that the above method is fully applicable not only under vacuum conditions but also under atmospheric pressure conditions.

That is, the present invention aims to further develop and expand the previously proposed production of a soil conditioner by heating and drying organic sludge and boiler ash under high vacuum, and to more easily carry out the production under atmospheric pressure conditions. That is.

(Means for Solving the Problems) A feature of the present invention that satisfies the above-mentioned object is that natural materials such as municipal waste incineration ash and boiler ash and external sludge produced by the utilization sludge method are heated under atmospheric pressure. The purpose is to evaporate water and odor while stirring and kneading, and to obtain a soil conditioner by pulverizing the material.

(Function) Normally, the organic sludge mixed above contains 80 to 90% water, three elements necessary for plants, nitrogen, phosphorus, and potassium, and a large amount of organic matter comparable to compost.

Therefore, when such sludge is mixed with boiler ash by heating and stirring as in the present invention, silicon dioxide, alumina, sodium oxide, calcium oxide, etc. contained in the boiler ash,
Reacts with carbon and becomes CaO+H20→Ca(OH)z +236 Cal/
mdNazO-111zO→Nz0H 5iO2+2NzOH-NazSiOz +HzOA
I-203+ 2NzOH-2NzA jl! 0□+
It becomes HzO.

Therefore, Ca (OH) 2 provides a soil improvement agent that has alkalinity and is suitable for acidic soils and low-nutrient soils.

Note that the carbon contained in the ash adsorbs odors and has a deodorizing effect.

(Example) Hereinafter, further specific examples of the above method of the present invention will be described.

The figure shows an outline of the mixing and stirring tank used to carry out the production method of the present invention.
) is an inlet for organic sludge and boiler ash from a food processing factory precipitated by the activated sludge method, (3) is a stirring blade attached to a stirring shaft (4) connected to a reducer (5), (6
) is a heating jacket, (7) is a delivery port for the obtained granular soil conditioner, (8) is a water and odor evaporation port,
In producing the soil conditioner, organic sludge precipitated by the activated sludge method and boiler ash are fed into the tank (1) through the inlet (2) and heated, stirred and kneaded in the tank (11). It can be obtained by drying to evaporate the water content through the evaporation port (8) and remove odor at the same time, and then sending the resulting reaction product of sludge and boiler ash out of the delivery port (7) in the form of powder.

Next, we will discuss the situation when producing a soil conditioner using the above-mentioned mixing tank. First, the organic sludge used contains three elements, nitrogen, phosphorus, and potassium, which are necessary for plants, and organic matter comparable to compost. Contains a large amount.

This is measured by the fertilizer analysis method. For example, sludge (80-90% moisture) contains nitrogen (N) 3.6-0.6% phosphoric acid (PzOs) 1.9-0.55% potassium (
K2O) 0.23-0.15% Calcium (Cab
) 1 to 4% of each element is included.

On the other hand, according to JIS-M-8815, the boiler ash component is silicon dioxide (SiOz) 31.3 to 7.9
%Alumina (AβzL) 18.4~2.2
% iron oxide (FezO:+) 4.48~0
．． 64% Sodium oxide (NaJ) 0.87~
0.098% Calcium oxide (Cab) 9
~60% Magnesium oxide (MgO) 0.67~
1.5% titanium oxide (TtO□) 1.07
~0.22% Carbon (C) 22.4
~2% moisture, 0.9~0%, etc. are included.

Therefore, if both of these are fed into the tank and mixed, the total water content will be lower than the water content of the boiler ash, and the dry water content will be reduced.

Then, the heating jacket (6
) is maintained at about 150°C or higher and heated and kneaded, the chemical reaction described above occurs, namely, CaO+H2O→Ca(OH)z +236 Cal
/mdNazO+ HzO→N20H 5iO, +2N20H-Na2SiO, +HzO82□
Heh ”2NzOIl →2N2A N O□+11
□0 gives NazSiOz.

In this case, the water contained in the organic sludge or the like in the tank evaporates from the upper evaporation port (8) by heating, and at the same time, the odor is also evaporated and removed together.

In addition, sterilization was carried out by the following method using atmospheric pasteurization method: Shigella 45゛C Raw roundworm eggs 50℃ Bovine abortion bacteria 55℃ Salmonella 60℃ Escherichia coli 60゛C X 30 seconds X 60 seconds X 60 seconds X 30 seconds Although any method may be used, the vacuum boiling sterilization method according to the present invention enables more complete sterilization of sludge.

In this way, it is obtained by reacting in the tank (1), and the outlet port (
The product sent through 7) has the following composition: Moisture 30-40% Organic 20-40% P2O, 0.6-2% N 1-4% Kzo 0.2-0.5% Ca (OH)
z 5-20% 5tOz
io~20% Aβ20. It has 5-10% Fe2O: +1-5% MgO0.7-1.5% 0 5-30% 2N2A ff O□, has alkalinity of PH9-12, and has the effect of compost.

Therefore, when used in acidic soil (PI+5 to 6) or low-nutrient soil, it serves as a soil improvement agent.

In other words, in recent years, there has been a strong tendency for conventional cultivation to place too much emphasis on chemical fertilizers, but on the other hand, the use of manure and manure on arable land, which is a basic condition, has decreased, and the overuse of various agricultural chemicals has become common.

As a result, the fertility of arable land has declined, the soil has become more acidic, and the number of areas with poor crop growth has increased.

As a countermeasure to this problem, a neutralization method using calcium (lime) has been adopted, and the application of calcareous materials has become commonplace and tends to be used unconsciously, and in some regions, the harmful effects of excessive lime are beginning to appear.

The soil conditioner according to the present invention prevents the adverse effects of such neutralization measures using lime, and particularly promotes the effect of organic sludge through the use of organic sludge in food processing factories.

Note that if the amount of compost is large, the decomposition rate of organic matter will be delayed.

It is generally said that the optimum C/N ratio (C is carbon, N is nitrogen) is 20 when composting.

According to the present invention, this optimum composting ratio can be approached when adding boiler ash.

(Effects of the Invention) As described above, the present invention is a method for producing a soil conditioner by kneading organic sludge generated from food processing factories, etc. and natural ingredients generated from boilers, etc., and heating and drying. By making use of the constituent elements contained in discarded organic sludge and mixing it with boiler ash, it is made alkaline with a pH of 9 to 12. At present, the soil, which is often acidified due to excessive fertilizers, can be absorbed by plants. In addition to regenerating the soil, which is necessary to become a fertilizer and where microbial activity becomes active at a pH of 6 to 7, it can also be used as a soil conditioner to achieve nutrient reinforcement for nutrient-poor soil, and especially for boilers. By mixing it with ash, etc., it has the remarkable effect of opening the way to the use of boiler ash, whose use was previously restricted, and facilitating the granulation of organic sludge.

In addition, the production of the present invention is not only relatively simple by heating and drying under atmospheric pressure, but also the odor is evaporated with the evaporation of water, eliminating the problem of organic sludge, which has conventionally suffered from odor. Another advantage is that the treatment can be carried out under a favorable atmosphere.

Furthermore, the use of boiler ash simplifies the use of quicklime used in sludge treatment, and at the same time solves the problem of boiler ash pollution.The present invention has been highly praised for its practical effects as part of pollution treatment. be done.

[Brief explanation of the drawing]

The figure is a schematic diagram showing one example of a tank used in carrying out the present invention. (Former...mixing stirring tank, (2)...inlet, (3)...
... Stirring blade, (4) ... Stirring shaft, (5) ... Reducer, (6) ... Heating jacket, (7) ... Delivery port, (8) ... Evaporation port.

Claims (1)

[Claims] 1. Mix organic sludge produced by the activated sludge method in food processing factories with ash such as municipal waste incineration ash or boiler ash, heat, stir, knead, and dry under atmospheric pressure to remove moisture and odor. A method for producing a soil conditioner using sludge, which comprises evaporating the sludge and ash to form powder.