JPH0662354B2 - Highly concentrated organic composting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention prevents the use of diluting water for human livestock excrement or other high-concentration organic wastewater, which is a major source of environmental pollution, or Even if you use it, just use a small amount of diluted water that is equal to or less than the amount of wastewater to be treated,
Prevents environmental pollution due to high-concentration organic wastewater by solid-liquid separation by a predetermined treatment process, the liquid part can be used for purified water that meets water quality standards, and the solid part can be used as high-quality organic fertilizer / compost At the same time, the present invention relates to a method for purifying a high-concentration organic wastewater by solid-liquid separation and a method for producing an organic fertilizer / compost, in which the discharged / discarded organic components are used as high-quality organic fertilizer / compost for agricultural use.

(Prior Art) Conventionally, as a combined treatment method of human waste and gray water by solid-liquid separation, Japanese Patent Application Laid-Open No. 56-129097 has been disclosed. Further, as a sludge treatment method, JP-A-55-51
The thing of the 498 gazette was disclosed.

As a conventional high-concentration organic sewage treatment method, there has been a standard activated sludge method or a method partially applying it. For example, there is an activated sludge method as shown in FIG. The process of treating human excrement, which is an example of high-concentration organic wastewater by the activated sludge method,
After removing sand and contaminants from the dirty water, put it in a storage tank to make the liquid uniform or adjust the pH if necessary.
After that, a certain amount of water is continuously diluted with a large amount of diluted water (10 to 20 times volume) and pressure-fed to the aeration tank. The (activated sludge) oxidizes and decomposes and assimilates the organic substances in the wastewater, and the purification of the wastewater proceeds.

Then, the activated sludge mixture that has been purified is transferred to a settling tank and retained and settled for a certain period of time, so that the activated sludge and the supernatant liquid are separated, and the supernatant liquid is discharged after a predetermined sterilization operation, and the sedimented activated sludge is discharged. A part of the inside is circulated back to the aeration tank by a sludge pump, the remaining excess sludge is further concentrated by a dehydrator, the dehydrated cake is landfilled or incinerated, and the desorbed liquid is returned to the storage tank. I was returning.

However, this method increases the amount of sewage by pouring a large amount of diluted water as described above, so that the facilities such as the aeration tank and the sedimentation tank become large, and the operation management becomes complicated and the facility cost increases. It also had a number of drawbacks such as an increase in water supply and facility costs due to the diluted water supply facility, and an increase in operation and maintenance costs such as the power cost of the blower due to an increase in the aeration volume of the aeration tank.

(Problems to be Solved by the Present Invention) Japanese Patent Application Laid-Open No. 56-129097 discloses
A solid-liquid separator separates excrement and washing water excreted in domestic toilets into solids mainly consisting of feces and dust paper, and urine and liquid mainly consisting of washing water, and the solids are directly composted. This is a treatment method in which the liquid content is biologically treated by the catalytic oxidation method, the sedimentation tank separation liquid is discharged, and the excess sludge is mixed with the above solid content and composted.

However, since the present invention is intended to process a large amount of collected manure that has been stored for a long time in the toilet tank,
Dung is dissolved in urine by the time it stays in its original form,
Therefore, the solid-liquid separation is not easy. That is,
Unlike the one disclosed above, solid-liquid separation is not carried out at the beginning of the treatment, and contaminants which interfere with the subsequent treatment are separated by a screen, and the separated contaminants are incinerated.

Further, in the merger method disclosed above, not only human waste but also gray water is targeted for treatment, which is a so-called merger treatment. From the manure side, it can be said that it is a dilution treatment system using gray water, which is the gist of the present invention. It is significantly different from undiluted or low-dilution treatment.

Further, while the one disclosed above employs a sedimentation tank for solid-liquid separation of activated sludge, the present invention does not use a sedimentation tank for solid-liquid separation of activated sludge immediately after biological treatment. , There is a marked difference between the two.

Further, the conventional disclosure of JP-A-55-51498 targets surplus sludge, first settling pond sludge, sewage sludge mixed with them, or raw urine sludge before subjecting to composting treatment. The gist is a method of wet-oxidizing the object to be treated to bring it into a state of good dehydration, dehydrating it, and then fertilizing the separated solid (dehydrated sludge).

However, the present invention does not employ the treatment method as described above, and further, the present invention does not directly fertilize raw urine, and both of them are remarkably important in the gist of the invention. It's different.

Further, the present invention, regardless of the pollutant concentration of high-concentration organic sewage, even when diluting water is not used or is used, the amount of sewage to be treated is kept equal to or less, and water is saved, and the activated sludge mixture liquid The precipitation tank for solid-liquid separation was omitted. As a result, the equipment such as pipes and pumps for returning sludge and for returning the dewatering liquid from the dehydrator was omitted, so the facilities can be simplified and simplified, and it becomes possible to efficiently purify the wastewater. In addition, it is possible to reduce facility costs, management costs, power costs, etc. and simplify operation management. In terms of operation management, the sludge settling property (SVI) in the conventional settling tank is controlled, which is a great deal. The operation management is very easy because it does not require strict adjustment of the ratio of the amount of microorganisms to the amount of organic matter, that is, the BOD-MLSS load, which requires a lot of labor.

Furthermore, it is possible to obtain purified water that conforms to the water quality standard value, while solid matter (dehydrated cake) is used as a high-quality organic fertilizer.
It is produced as compost and contributes greatly to agriculture.

(Means for Solving Problems) In the present invention, as the first step, human livestock excrement or high-concentration organic sewage carried into an input tank is subjected to sedimentation of contaminants contained in the excrement or sewage. After being removed through a pond, a crusher, a drum screen, etc., the residue is removed and temporarily stored in a storage tank in order to homogenize the urine. As a second step, the removed urine from which contaminants have been removed from the storage tank in the above step Also, the wastewater is transferred to the adjustment reaction tank and mixed with a suspension containing primary humic substances obtained by oxidizing the wastewater components to be treated that have accumulated in the main tank in advance, and air is sent for aeration to perform biological purification treatment. As a third step, the raw sewage and sewage in which the primary humification has been completed in the adjustment reaction tank in the second step, and the mixed liquid of human waste, sewage and activated sludge are directly mixed in the adjustment tank without using a precipitation tank. After transfer and temporary storage, quantitative aggregation Sent to 応槽, by pH adjustment, if necessary, after the pH adjustment,
Inorganic coagulant is added and coagulated at a predetermined pH, and the coagulation treatment liquid is separated into a dehydrated cake and a desorption solution and a filter cloth washing water mixed solution using a dehydrator, and the desorption solution and the filter cloth washing water are separated. The mixed liquid is sent to the discharge process, subjected to a predetermined treatment, and then discharged, and as the fourth process, the dehydrated cake produced in the previous process is adjusted in pH, temperature, moisture content, air flow rate, etc. by a ripe composting device. However, it is a method of composting high-concentration organic components so as to increase the degree of humus and to produce true rot plants.

(Example) An example of the present invention will be described below with reference to the drawings of human excrement in high-concentration organic wastewater, with reference to the drawings.

As a first step, impurities and the like contained in the excrement carried into the input tank 1 are removed through the sand basin 2, the crusher 3, the drum screen 4, etc., and then temporarily stored in the storage tank 5 for removal. Homogenize the waste urine.

In the second step, the decontaminating urine from which the contaminants have been removed is transferred to the adjustment reaction tank 6 and a suspension containing primary humus obtained by oxidizing the wastewater component to be treated that is retained in the main tank in advance is prepared. Oxidative decomposition and assimilation of organic substances in sewage occur due to the continuous purifying action of organic compounds in the sewage that are mixed and mixed with various bacterial groups in the mixed liquor. And promote the initiation of humus.

Adjusting the reaction vessel 6, per unit tank capacity, 1~5m ³ / m ³ · Hr
Blow off the air or the mixed gas of air and oxygen. The treatment period is 1 day when the amount of BOD in human waste is about 0.2 kg BOD / kg MLSS.d per 1 kg of sludge in the primary humic suspension.

Judgment of treatment completion is that pH, decrease in electrical conductivity, increase in dissolved oxygen value, decrease in ammonia nitrogen (NH ₄ -N) and expression of oxidized nitrogen (NO _X -N) or immediately before that, COD,
Reduction of BOD value, reduction of coliform bacteria and general bacteria,
It is performed by a unique numerical value that indicates the primary humus of sewage components, such as the appearance of unique protozoa. In addition, the amount of primary humus suspension left in the main tank 6 in preparation for the introduction of new wastewater after the treatment is
The amount is 100 to 600% with respect to the amount of excreted urine, and the amount is adjusted so as to achieve the above load amount.

The load value may be adjusted depending on the concentration of human waste, the quality of discharged water and the removal rate of nitrogen, and the number of treatment days may be changed within the range not exceeding 3 days depending on the above conditions.

As the third step, in the adjustment reaction tank 6, the raw sewage whose primary humus has been completed is transferred to the mixing adjustment tank 7 and temporarily stored,
After quantitatively sending it to the agglutination reaction tank 8 and adjusting the pH to about 9 to 10 with a pH adjuster (NaOH, etc.) as necessary, an inorganic aggregating agent (eg ferric chloride, FeCl ₃ )
Add 500 to 6,000PPm, and agglomerate by the usual agglomeration operation at pH around 4.0 to 4.5. Further, this coagulation treatment liquid is subjected to solid-liquid separation using a vacuum dehydrator 9 (other types of dehydrator can also be used) to obtain a dehydrated cake, a debris liquid, and a filter cloth washing water mixed liquid.

As the fourth step, the dehydrated cake produced in the previous step (water content of 50 to 80% by the adopted dehydrator) is appropriately adjusted while adjusting the pH, temperature, water content, air flow rate, etc. by the fully-ripened composting device 10. The degree of humus is further increased by operation management, and this process is completed by the production of true humus plants. In terms of agriculture, the source of plant nutrients, the improvement of physical and chemical properties of soil,
Furthermore, it will produce fully-ripened compost, which is expected to maintain and enhance the biota in the soil and its activity.

The treatment period in this step is 45 when a crude organic matter such as sawdust and straw is added as a moisture regulator at the beginning of fermentation.
-60 days, or 20-30 days when a product (compost) or other inorganic substance is added without using a crude organic substance.

Still another step is to remove the desorbed liquid from the dehydrator 9 and a small amount of solid sludge contained in the washing water mixture obtained by washing the filter, so that the sludge is transferred to the settling tank 11 and retained and settled for 3 to 4 hours. When this is done, clean supernatant water is obtained, and part of it is reused as filter washing water, so it is transferred to the water tank 12, and the rest is discharged after a predetermined sterilization treatment.
A small amount of concentrated sludge settled in the settling tank 11 is returned to the mixing adjusting tank 7. In addition, in order to remove a small amount of solid sludge, a removing device such as a mashing device instead of the precipitation tank may be used. 13 is an incinerator, 14 is a blower, 15 is a screw press, and 16 is a sterilization tank. 7a is a pH adjusting tank.

By the way, the human waste treatment process based on the conventional activated sludge method is
As shown in the figure, and explained below, after the impurities in the human waste are removed, they are temporarily stored in the storage tank 17 to homogenize the liquid. Next, while continuously feeding a fixed amount to the waterfall tank 18, the dilution is made 10 to 20 times, and the blower 19 is operated to blow air. Then, organic substances in the human waste are oxidized and decomposed by the aerobic bacteria groups (active sludge) that are actively active, active sludge is formed, and purification of wastewater proceeds. Then, the purified water containing the activated sludge in the form of huge particles is transferred to the settling tank 2
Transfer to 0 and let it settle for 2-3 hours. The activated sludge and the supernatant liquid are separated by this precipitation, the supernatant water is discharged, part of the activated sludge that has settled is returned to the water tank 18 by the sludge pump 21, and the residual excess sludge is further dewatered by the dehydrator 22. Increase the degree of concentration, incinerate or landfill the solid (dehydrated cake), and circulate the liquid again to go through the same purification process. The above is the treatment process by the conventional activated sludge method.

The present invention is processed by the respective steps (first step to fourth step) as described above, and further experimental operation has resulted in the following results.

(1) Details of the experiment The water quality of the collected human waste collected by the human excrement vacuum car after removing impurities in the first step is as follows.

pH: Average 8.0 SS: Average 6,500PPM BOD: Average 6,100PPM COD: Average 4,100PPM Adjusting reaction tank The above-mentioned human waste is stored in a main tank that stores a suspension of primordial humus obtained by previously oxidizing wastewater components. In order to make primary mixed humus, the mixture is poured into the tank and the specified amount of air is continuously supplied to the tank.

Adjusted load 0.1 to 0.25 kg BOD / kg MLSS ・ d Suspension storage amount 100 to 600% of input human waste amount Treatment period 1 to 2 days Air supply amount 3 m ³ / m ³・ Hr Aggregation operation Inorganic coagulant (FeCl ₃ ) 1,500 to 6,000 PPM, p
After adjusting H to about 4.0 to 4.5, ordinary stirring and aggregation operations are performed.

Dehydration and Settling Using the vacuum dehydrator 9 on a scale of ³ m ³ / Hr, the coagulated water is dehydrated. In order to remove a small amount of solid matter suspended in the desorbed liquid and the filter cloth washing water, the solid solution was transferred to the settling tank 11 for 3 to 3 times.
Allow to settle for 4 hours. Since part of the supernatant water is reused as filter cloth washing water, it is transferred to a water tank, and the rest is discharged after a predetermined sterilization treatment. The precipitated solid content is returned to the mixing adjusting tank 7.

Discharged water quality pH: 5.8 to 8.6 SS: 30 PPM or less BOD: 20 PPM or less Escherichia coli group number 100 / cm ³ or less Manufacture of compost Dehydrated cake separated by dehydrator 9 (water content 75 to 85
%), And after adjusting the addition of sawdust as a water content adjusting material, a composting operation for 45 days is performed in the fully-ripened composting device 10.

(2) Experimental results Purified water that meets the water quality standards was obtained.

It is possible to produce 8 to 13 kg (about 50% water content, excluding the water content adjusting material) of fully-ripened compost per 1 kl of human waste.

When the treatment method of the present invention based on the above-described experimental operation is compared with the conventional treatment method, it has been found that there are the following results (No. 1 and No. 2).

(Effects) (1) In the present invention, after the adjusting reaction tank in the above-mentioned second step, the precipitation tank generally installed for separating the treated water after the biological treatment and the activated sludge is omitted. As a result, the equipment such as pipes and pumps for returning sludge and for returning the dewatering liquid from the dehydrator was omitted, so the facilities can be simplified and simplified, and it becomes possible to efficiently purify the wastewater. , Operation cost, facility cost, power cost, etc. and simplification of operation management can be realized. In terms of operation management, sludge settling (SV
The operation management became very easy because it did not require strict adjustment of the ratio of the amount of microorganisms to the amount of organic matter, that is, the BOD-MLSS load, which required a great deal of labor to control I).

Furthermore, it is possible to promote oxidative decomposition and particle formation accompanying the primary humification of high-concentration organic sewage components without dilution, and at the same time, to perform various reactions such as growth, coagulation and oxidation of suspended sludge in a mixed liquid. By accelerating together, after generating primary humic substances, the inorganic coagulant was used to enlarge the fine particles and facilitate solid-liquid separation, so that a large amount of diluted water was not used. The purified water obtained by solid-liquid separation complies with water quality standards and can be discharged or reused. On the other hand, solid content is an epoch-making method that can be fully composted and can greatly contribute to soil improvement for agriculture.

(2) Further, the present invention, without using a large amount of diluting water that was considered as conventional common sense, even under high-concentration organic wastewater, while maintaining various activities of microorganisms, to promote primary humification, Efficient purification has been achieved by continuous coagulation and dewatering operations. In particular, it is no longer necessary to consider sludge settability in the settling tank, which was the biggest issue in terms of operation of the conventional activated sludge method. It has the advantage that it does not require a high degree of knowledge, while the management aspect is much simplified and the number of facility operation personnel can be reduced.

(3) In addition, since the present invention does not use diluting water, the facility does not bloat, the facility can be constructed at a lower cost than before, and at the same time, the operating cost can be reduced and the water quality standard is met. In addition to obtaining purified water, high quality compost can be produced, and therefore, it has an advantage that it can greatly contribute to prevention of environmental pollution and soil improvement of agricultural land.

[Brief description of drawings]

FIG. 1 is a diagram showing a treatment process of a high-concentration organic component composting method of the present invention, and FIG. 2 is a diagram showing a treatment process of a conventional human feces wastewater. 1 ... Input tank, 2 ... Settling tank, 3 ... Crusher, 4 ... Drum screen, 5 ... Storage tank, 6 ... Regulating reaction tank, 7a ... pH adjusting tank, 8 ... Aggregation reaction tank, 9 ... Dehydrator, 10 ... Ripe composting device, 11 ... Settling tank, 12 ... Water tank, 13 ... Incinerator,
14 ... Blower, 15 ... Screw press, 16 ... Sterilization tank.

Claims (1)

[Claims] 1. As a first step, human livestock excrement and high-concentration organic sewage carried into an input tank are treated with a sand basin, a crusher, a drum screen, etc. to remove impurities contained in the manure and sewage. After removing via the wastewater, the wastewater is temporarily stored in a storage tank in order to homogenize the urine, and as the second step, the wastewater removed from the storage tank in the above-mentioned step is transferred to the adjustment reaction tank. , Is mixed with a suspension containing primary humic substances obtained by oxidizing the wastewater component to be treated that has accumulated in the main tank in advance, air is sent to perform aeration to perform biological purification treatment, and as a third step, In the adjustment reaction tank in the second step, the raw sewage and sewage whose primary humus has been completed, and the mixed liquid of the sewage, sewage and activated sludge are directly transferred to the mixing adjustment tank without using a sedimentation tank and temporarily stored, and then quantitatively To the flocculation reaction tank and adjust the pH if necessary By the agent, after adjusting the pH, add an inorganic coagulant, aggregate at a predetermined pH, further aggregating treatment liquid is separated into a dehydrated cake and desorption liquid and filter cloth washing water mixture using a dehydrator, The desorbed liquid and the filter cloth washing water mixed liquid are sent to a discharge process and subjected to a predetermined treatment and then discharged, and as a fourth process, the dehydrated cake produced in the previous process is subjected to pH, temperature and moisture by a ripe composting device. A method for composting high-concentration organic components, in which the degree of humus is further increased and the production of true humus is performed while adjusting the rate and air flow.