JP2007075770A - Moisture controlling material for treating sludge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture controlling material for treating sludge, a small quantity of which is mixed in original sludge, so that the moisture control of original sludge can be started instantly and a fermentation environment of a microbe can be adjusted to enable fermentation promptly. <P>SOLUTION: The moisture controlling material for treating sludge is obtained by molding an organic cultural body composed of a microbe-combined material into particles having 5-10 mm particle size and sticking an exothermic drying aid containing magnesium oxide, iron chloride and silica as principal components to the surface of each of molded particles of the organic cultural body. The water content of the organic cultural body is ≤30% and the mass ratio of the exothermic drying aid to the organic cultural body is around 1/10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, when fertilizing organic matter-containing sludge such as livestock manure and composting it, moisture mixed in the treated sludge for the purpose of setting the moisture content of the treated sludge (raw material sludge) to a moisture content suitable for promoting fermentation It relates to a regulator.

  For sludge treatment containing organic substances such as livestock manure and domestic wastewater, conventional methods such as simply landfilling, incineration of sludge dehydrated cake, or fermenting and composting (composting), etc. Is adopted. However, in the landfill treatment method, it is difficult to secure a landfill site due to problems such as bad odor, off-flavor, and generation of carbon dioxide, and the incineration method is not practical. The problem of environmental pollution and high cost (construction of incinerators and large consumption of incinerator fuel) due to generation of toxic gases such as dioxins has not been solved. Therefore, recently, a method of composting by fermentation is considered desirable, and many proposals have been made regarding composting of sludge.

  An important issue in composting sludge is to adjust the optimal water content for fermentation treatment and increase the fermentation rate for composting in a short time. That is, composting of sludge is nothing but an organic fertilizer by decomposing and changing the organic matter in the sludge by the action of microorganisms, and the working microorganisms are mainly aerobic microorganisms. Moisture is essential for the function of this microorganism, but if the moisture content is too high, the air permeability deteriorates. Therefore, it is usually essential to adjust the moisture content in the sludge to at least 65% or less as the initial step of fermentation treatment. It becomes. However, this initial moisture adjustment is actually very difficult, and there is currently nothing that is sufficiently satisfactory in terms of cost, workability, and quality of finished compost (product).

  Conventionally, as a method of adjusting the moisture content of raw material sludge, a method of adjusting moisture mechanically and a method of adjusting moisture by mixing a humidity control material (dry matter such as sawdust and straw) in the raw material sludge have been adopted. However, in the case of the former (mechanical humidity control), it is inevitably a large-scale plant using expensive machines, and new dryers and agitators have been developed, but there are still cost problems. It is not to clear. In the case of the latter (humidity control using a humidity control material), a water conditioner (dry matter) that is equal to or more than the amount of sludge is required to adjust the water content of high water content sludge (eg, cow manure) to about 65%. I need. However, if the amount of moisture adjusting material (dry matter) to be mixed increases, the fermentation rate will slow down accordingly, and the total amount of compost will also increase, so that work efficiency and equipment efficiency will deteriorate, resulting in increased processing costs. Problems such as inviting.

In recent years, processed products of zeolite containing carbonized sludge and zeolite have been used as humidity control materials, cement and glass foaming agents have been added to other humidity control materials, and further, the reaction heat has been increased to promote fermentation biodegradation of microorganisms. In order to promote, the method of adding an aluminum-based substance has also been carried out, but none of the results have been satisfactory in terms of humidity control rate, fermentation rate and cost, and when an aluminum-based additive is used In that case, there are concerns about the effects of aluminum remaining in the treated water on the human body, and problems such as causing phosphorus deficiency in the soil when returned to farmland (fertilization) have been pointed out.
Japanese Patent Laid-Open No. 5-202350 Japanese Unexamined Patent Publication No. Hei 8-97095 Japanese Patent Laid-Open No. 9-40383 JP 2001-261475 A JP 2002-79296 A JP 2004-123434 A

  The present invention was made in order to solve the problems of the conventional moisture regulator or moisture regulation method described above. By mixing a small amount in the raw material sludge, the moisture is instantly adjusted and the microorganism fermentation environment is maintained. It is an object of the present invention to provide a moisture adjusting agent that enables rapid fermentation promotion.

  As a result of repeated experiments to solve the above-mentioned problems, the present inventor has found out a form and a component composition that are extremely effective as a moisture adjusting agent for sludge treatment, and has led to the following invention based on the knowledge.

According to the first aspect of the present invention, an organic culture composed of a complex of microorganisms is formed into a granular shape having a diameter of 5 mm to 10 mm, and the organic culture is used as a core for heat-generating drying mainly composed of magnesium oxide, iron chloride, silica and the like. It is a moisture adjusting agent characterized by comprising an auxiliary agent.
The organic culture that forms the core of the moisture adjusting agent of the present invention is a sludge containing organic substances such as livestock manure, which is dehydrated and dried to a degree that it can be easily formed into granules, and the dehydrated sludge is formed into granules having a diameter of 5 mm to 10 mm. is there. The exothermic drying aid is mainly composed of magnesium oxide, iron chloride and silica having hygroscopicity and exothermic properties. This exothermic drying aid is attached to the surface of the organic culture to form a double-structured particle as a whole, which is the moisture adjusting agent of the present invention.

The invention according to claim 2 is the moisture regulator according to claim 1, wherein the moisture content of the organic culture is 30% or less.
By making the water content of the organic culture that is the core 30% or less, when it is mixed in the raw material sludge, the initial reaction is fast and the synergistic effect with the exothermic drying aid enables more rapid humidity conditioning and fermentation. .

The invention according to claim 3 is the moisture adjusting agent according to claim 1 and claim 2, wherein the mass ratio between the organic culture and the exothermic drying aid attached to the organic culture is approximately 10 to 1. It is the moisture adjusting agent characterized by these.
It is considered that the moisture adjusting agent according to the present invention is optimal to have a mass of about one-tenth of the raw material sludge in consideration of the humidity control efficiency, fermentation efficiency, and overall processing amount reduction effect.

The invention according to claim 4 is the moisture adjusting agent according to any one of claims 1 to 3, wherein an approximate proportion of components of the exothermic drying aid attached to the organic culture is 50% magnesium oxide, 10% iron chloride, 20% silica. % And other 20%.
Considering the characteristics of the sludge to be treated, the component ratio of the exothermic drying aid needs to be adjusted slightly, but in general, the approximate ratio is 50% magnesium oxide, 10% iron chloride, 20% silica, 20% other It is preferable that the sludge is composed of livestock manure. Examples of other components include magnesium phosphate, magnesium carbonate, calcium bicarbonate, and other silicons.

  First, the operation principle of the moisture adjusting agent according to the present invention will be described. The moisture of the raw material sludge is attracted to the gap of the moisture adjusting agent in a granular form, and adheres to the surface of each particle (see FIG. 1). Next, the adsorbed moisture reacts with magnesium oxide and iron chloride in the exothermic drying aid adhering to the surface to generate heat, and at the same time, the moisture stored in the silicon county such as silica having a porous shape is added to the organic culture. Water is supplied. This heat generation and water supply immediately start the decomposition of microorganisms that form organic cultures. In the organic culture body, the transpiration action is further enhanced by the gelation reaction of the organic culture body, whereby the water molecules become smaller and diffused to make the water uniform (see FIG. 2).

As described above, when the moisture adjusting agent according to the present invention is used, the following effects can be obtained by performing the water absorption, heat generation, transpiration, and fermentation decomposition efficiently and continuously.
(1) Moisture adjustment at the initial stage can be realized in a short time by instantly preparing the fermentation environment of the raw material sludge.
(2) Since the activity of microorganisms can be accelerated rapidly, water quality purification and odor reduction in sludge can be performed simultaneously.
(3) Since the amount of the moisture adjusting agent mixed into the raw material sludge is small, the total amount is not increased and the fermentation process can be greatly reduced. As a result, it is possible to significantly reduce costs together with effective use of facilities such as land and buildings.
(4) Since the finished state of compost is easy to be made uniform, it can be quickly returned to the natural environment.
(5) No sewage is produced in the fermentation process and there is no addition of an aluminum-based flocculant or the like, so that the natural environment is not adversely affected.
(6) Because of high-temperature fermentation, pathogenic bacteria and plant seeds in the sludge are killed and detoxified, and a high-quality organic fertilizer is obtained.

The embodiment of the present invention will be described below based on experimental data (FIGS. 3 to 5) compared with a conventional example.
FIG. 3 shows a case where a moisture conditioner having an organic culture body as a core according to the present invention is used under conditions of an air temperature of 35 degrees, a humidity of 75%, and a mass of 100 grams, and a humidity control material made of zeolite or diatomaceous earth. It is a graph at the time of carrying out a comparative experiment of the humidity control (water absorption) rate in the case of being. As is clear from this experimental data, the moisture adjusting material according to the present invention immediately started to absorb water after mixing, and soon exhibited a humidity control effect exceeding 80%, and the effect was maintained for a long time. On the other hand, when a conventionally used humidity control material such as zeolite was used, the water absorption rate was slow and the water absorption rate remained at about 50% at the maximum.

  FIG. 4 is a graph comparing temperature changes during fermentation of cow dung sludge. From this experimental data, when the water conditioner having the organic culture according to the present invention as a core was used, it was attached to the organic culture. It can be seen that there is a rapid temperature increase due to the synergistic effect of the reaction heat of the exothermic drying aid and the heat of decomposition by the organic culture, and that the fermentation process can be completed in a short period of time due to the subsequent temperature decrease.

  FIG. 5 is a graph showing the moisture change during fermentation of cow dung sludge. From this experimental data, it is clear that the humidity control effect is high when the moisture regulator according to the present invention is used. In the conventional method, in order not to increase the amount of the humidity-controlling material (dry matter etc.) to be mixed, a pretreatment step for reducing the raw material sludge to a water content of about 80% in advance is indispensable. When the moisture adjusting agent is used, the initial fermentation environment can be adjusted in a short time (the water content of the raw material sludge is set to 65% or less) even without such pretreatment.

Explanatory drawing which shows the principle of the water | moisture-content fusion | melting effect | action by this invention. Explanatory drawing which shows the principle of the exothermic transpiration action by this invention. Comparison experiment graph of humidity control rate. Comparison experiment graph of temperature change during fermentation. Comparison experiment graph of moisture change during fermentation.

Claims (4)

  A water conditioner for sludge treatment, an organic culture composed of a complex of microorganisms is formed into granules having a diameter of 5 mm to 10 mm, and the organic culture is used as a core and contains magnesium oxide, iron chloride, silica and the like as main components. A moisture regulator characterized by comprising an exothermic drying aid.   The moisture regulator according to claim 1, wherein the moisture content of the organic culture is 30% or less.   3. The moisture adjusting agent according to claim 1, wherein the mass ratio of the organic culture and the exothermic drying aid attached to the organic culture is approximately 10 to 1. 3.   The moisture content according to claims 1 to 3, characterized in that the approximate component ratio of the exothermic drying aid attached to the organic culture is 50% magnesium oxide, 10% iron chloride, 20% silica, and 20% others. Regulator.

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