JPH067958B2 - Microbial activator using sewage sludge incineration ash and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] This invention uses a sewage sludge incineration ash used to remove organic matter in wastewater and the like (hereinafter referred to as microbial activation material). And its manufacturing method.

[Conventional technology]

When removing organic matter by a fluidized bed, sand, activated carbon, plastics, zeolite, etc. have been conventionally used as an activator of microorganisms that decompose the organic matter, that is, a medium for adhering and proliferating the microorganisms.

[Problems to be Solved by the Invention]

However, sand has a very small surface area and is smooth so that microorganisms are unlikely to adhere to it. Moreover, since the specific gravity is as large as about 2.6 g / cm ³ , when moving in a fluidized bed, the particles of sand collide with each other and the attached microorganisms are peeled off. Since it has poor hydrophilicity and cannot be expected to elute minerals, it cannot create a favorable living environment for microorganisms.

Activated carbon has a large surface area, but the pore size is too small to allow microorganisms to enter the pores. In addition, since the mechanical strength is low, when moving in a fluidized bed, the particles collide with each other and are crushed, resulting in black turbidity as well as destruction of the physical environment for microbial survival. The high price is also a drawback.

Like sand, plastic has a smooth surface, so that it is difficult for microorganisms to adhere to it and is hydrophobic, so the amount of microorganisms retained is small. In addition, since elution of minerals cannot be expected,
Like sand, it cannot create a favorable living environment for microorganisms.

Zeolites are hydrophilic and have an ion-exchange ability, but have weak mechanical strength, extremely small pores, and are not suitable as a retention medium for microorganisms.

As described above, each of the conventional activators has few surface pores suitable for survival of microorganisms and does not have an active structure.
Also, when viewed individually, the strength of the particles is large, but it is heavy and lacks fluidity in the fluidized bed, or lacks hydrophilicity.
There were drawbacks such as no elution of minerals and no expectation as a mineral supplement. Therefore, in the conventional activator,
There is a problem in that a large amount of microorganisms are retained and the function of activating them without proliferating is not sufficiently fulfilled, and therefore organic matter such as wastewater cannot be effectively removed.

The present invention has been made to solve such conventional problems, and (1) the ability to activate microorganisms to remove organic matter in water and retain a high concentration of microorganisms in a certain volume. Therefore, the ability to remove organic matter from water is high, and (2) the sewage sludge incineration ash can be effectively used, and (3) the microbial activation material that can also be used as a roadbed material and the production thereof. The purpose is to provide a method.

[Means for Solving the Problems]

The microbial activator according to the present invention comprises sewage sludge incineration ash, cement, obsidian foam powder and / or crushed obsidian powder (hereinafter referred to as obsidian powder), and a granular solidified product of a kneaded water.

Further, the method for producing a microbial activator according to the present invention is based on sewage sludge incineration ash as a base material, and cement and obsidian powder are added to the mixture and kneaded to obtain a kneaded product. It is characterized in that it is processed into granules and cured, or that it is cured and solidified into granules.

The sewage sludge incineration ash is a base material, cement is a solidifying material, and obsidian powder is a specific gravity adjusting material. The preferable mixing ratio of each of these materials is 50% by weight or more of sewage sludge incineration ash, 5% by weight or more of cement, and 1% by weight or more of obsidian powder.

[Action]

(1) Since the microbial activator is a granular solidified product of a water kneaded mixture of sewage sludge incineration ash, cement and obsidian powder, it has a large specific surface area and is close to the size of underwater microorganisms such as bacteria on the surface. It is an active structure with many pores. Therefore, it is easy to keep the microorganism at a high concentration and activate (proliferate) it.

(2) The microbial activator contains obsidian powder, and thus is a lightweight structure. Therefore, it is possible to circulate with fluidity in the fluidized bed. And this liquidity is
It can be set to the optimum one by changing the compounding amount of the obsidian powder to adjust the specific gravity as the activator.

(3) The microbial activator is a hydrophilic structure because it has a property that the composition sewage sludge incineration ash, cement, and obsidian powder are wet with water. That is, both water adsorption and water absorption are large. Therefore, the mineral components contained in the activator are easily eluted.

(4) The microbial activator has a structure that has a strength that does not easily break, because the cement that is its component has self-hardening property and the obsidian powder that is the component has a good effect on the hardening of the kneaded product. Become. There are three possible reasons why the obsidian powder has a good influence on the hardening of the kneaded product.

That is, (a) the obsidian powder has a characteristic that the pH is neutral while having SiO ₂ as a main component, and (b) the dispersibility of the obsidian powder is good, which effectively acts on the uniform mixing of the components. That is, (c) ammonia gas generated from sewage sludge incineration ash interferes with the hardening of the kneaded product, but obsidian powder effectively acts to remove this.

As described above, since the microbial activator according to the present invention has the strength that does not easily break, there is no risk of breaking during the circulation process in the fluidized bed.

〔Example〕

 Examples of the present invention will be described below.

First, a method for producing a microbial activator and properties and actions of the obtained microbial activator will be described.

(Production Method 1) 80% by weight of sewage sludge incineration ash having self-hardening property, 10% by weight of Boltland cement, and 10% by weight of obsidian foam powder are put in a mixer and mixed sufficiently. Then, 25% by weight of water is added to the obtained mixture and the mixture is kneaded well. At this time,
The kneaded material should be sandy with a little dampness.

Next, the sandy kneaded product is extruded into pellets by a pressure type extruder (disk type). About 2 pellets are extruded
Curing in wet condition for 4 hours. Due to the curing in the wet state, the strength of the pellet is developed. After the strength is developed, it is processed if necessary.

(Manufacturing method 2) 83% by weight of sewage sludge incineration ash having self-hardening property, 15% by weight of Boltland cement, and 2% by weight of obsidian foam powder were put into a mixer and mixed sufficiently, and then the resulting mixture was mixed with water 2
Add 5% by weight and knead well.

The kneaded material thus prepared is put into a rotating pan-type granulator and simultaneously sprayed with water, whereby spherical granulated materials can be continuously formed. The size of the granulation product is the number of rotations of the pan granulator,
Select freely by adjusting the angle and spray amount of water. The molded spheres are cured in a hermetically sealed wet state, if necessary.

(Manufacturing method 3) 80% by weight of self-hardening sewage sludge incineration ash, 10% by weight of Boltland cement, and 10% by weight of obsidian foam powder were put in a mixer and mixed well, and then the resulting mixture was mixed with water. 60% by weight of the mixture is added to make the mixture fluid, and the mixture is poured into a frame of a predetermined shape prepared in advance for curing, and then crushed.

Next, the properties of the microbial activation material obtained by the production method 1 were examined for each test item, and the following results were obtained.

(1) Grain structure The whole grain structure is as shown in the scanning electron micrograph of FIG. 1, and fine irregularities were formed on the surface. Second
The figure is an enlarged scanning electron micrograph of the particles shown in FIG. 1, showing a state in which obsidian foam powder is mixed. FIG. 3 is a further enlarged scanning electron micrograph showing that there are a large number of pores into which microbes easily enter.

(2) Compressive strength (Kgf / cm ² ) (according to JIS A 1108 compression test) (3) Surface area (by N ₂ BET method) The specific surface area was 53.5 m ² / g.

(4) Pore size distribution (N ₂ adsorption isotherm was analyzed by the Dollimore-Heal method) Many distributions were found with a radius of 100 Å or more.

(5) Hydrophilicity (a) Water adsorption (by gravimetric method using isothermal adsorption quartz spring of water vapor at 30 ° C.) Humidity was 0.23 WH _{2 O} / g · g ⁻¹ at 100% humidity.

(B) Water Absorption (According to Water Absorption Test of JIS A 1110) The water absorption was 46.2%.

(6) Weight (according to JIS A 1110) The absolute dry specific gravity was 1.14.

(7) Ion exchange capacity The cation exchange capacity was 31.6 meq / 100 g.

It should be noted that the cation exchange capacity, which is effective for the adsorption of ammonium ions, is close to that of cation exchange agents,
By X-ray diffraction analysis, it was found that there were few compounds with large crystallinity, they were similar to glassy substances and were close to the inorganic substances developed as catalysts.

(8) Chemical composition (9) Elution status of minerals (according to Environmental Agency Notification No. 13 of 1973) (a) Elution amount after one year of use (mg / l) (B) Elution amount immediately after production (mg / l) (Action) Next, the properties of the microbial activator as seen from the above data and the actions based on this property will be described.

(1) 53.5m ² / g of specific surface area by the measurement results, 1.4 m ² / g of硅鉱stone, has been developed as 0.7 m ² / g, or adsorbents sand. For example, silica gel 20-
Comparable to 30 m ² / g.

In addition, the pore size distribution is well developed above 100 Å (Fig. 3).

This means that the obtained activator has a large specific surface area,
In addition, it is shown that it is an active structure having many surface pores close to those of microorganisms in water such as bacteria. Perhaps the activator is a solidified product of a kneaded material of multiple materials such as sewage sludge incineration ash, Portland cement and obsidian foam powder,
It is probably because it is not composed of a single material like conventional sand, plastic, etc.

Due to such a structure, the activating material is suitable as a medium for adhering and proliferating microorganisms at a high concentration.

(2) The absolutely dry specific gravity of 1.14 in the measurement result is not inferior to the specific gravity of commercially available lightweight aggregate coarse particles of 1.20 to 1.30, which is said to be the lightest.

This shows that the obtained activator becomes a lightweight structure, and at the same time, the specific gravity, that is, the unit volume weight, can be changed by the compounding amount of the obsidian foam powder.

Therefore, the activator can be circulated in the fluidized bed with appropriate fluidity.

(3) All the components of the activator have a property of being wet with water, and the water adsorption property according to the measurement result is similar to that of silica gel or alumina. It can be said that the water absorption rate of 46.2% is a large value as compared with 6 to 15% of commercially available lightweight aggregate and 3% of sand.

These facts indicate that the obtained activator is a structure having hydrophilicity. For this reason, when the activator is in water, the mineral components therein are likely to be eluted. In the case of the microbial activation material of this example, Ca, K, etc. are 1
It will elute even after a year, and will not only serve as a mineral supply source for microorganisms, but also as an alkali supply source necessary for nitrification of ammonia nitrogen in water.

(4) From the results of the compressive strength test, it can be seen that the above-mentioned activator has a strength that does not break in the fluidized bed.

This is because Portland cement has self-hardening properties,
It is also considered that the obsidian foam powder has a good influence on the hardening of the kneaded product.

That is, (a) the obsidian powder has a characteristic that the pH is neutral while having SiO ₂ as a main component, and (b) the dispersibility of the obsidian powder is good, which effectively acts on the uniform mixing of the components. That is, (c) ammonia gas generated from sewage sludge incineration ash interferes with the hardening of the kneaded product, but obsidian powder effectively acts to remove this.

Therefore, there is no possibility that the activator will be destroyed in the process of circulating in the fluidized bed. Further, in the production of the microbial active material, for example, activated carbon powder, charcoal powder, zirconium oxide, by adding a powdery substance such as a calcium compound as necessary, the action based on the above properties is appropriately changed. Can be made.

Finally, the effect of removing organic matter when the above-mentioned microbial activator is used is clarified by an experiment for removing organic matter of artificial wastewater using an external circulation type three-phase fluidized bed shown in FIG.

(Experimental Method) First, the fluidized bed will be described. In FIG. 4, 1 is an annular flow tank, 2 is a supply port for supplying artificial wastewater to the flow tank 1, 3 is an air supply pipe for both oxygen supply and lift, 3 a is its ball filter, 4 is the flow tank 1. In the experiment, the activator obtained by the above-mentioned production method 1 was used. Reference numeral 5 denotes an outlet for artificial wastewater (treated water) which circulates in the fluid tank 1 and in which organic substances have been removed by the activator.

The experiment was conducted as follows. The activation material 4 having a particle diameter of 0.42 to 0.59 mm in the fluidized bed 1 having an effective internal volume of 3.76.
0.5 was added. Then, while supplying the artificial wastewater having the composition shown in Table 1 from the supply port 2, air was blown from the air supply pipe 3, and the activator was circulated in the direction opposite to the artificial wastewater by the air lift effect. The artificial wastewater was initially supplied in a small amount for acclimatization of microorganisms such as bacteria, and the load was gradually increased. The temperature was room temperature and the pH was not adjusted. The amount of air blown was 1.0 to 3.5 / min.

The treated water in which the organic matter was decomposed and removed by the microorganisms that adhered to and grew on the activator 4 was taken out through the outlet 5.

(Experimental results and evaluation) (1) The organic matter (BOD) concentration of the supplied artificial wastewater was about 500 mg / hour at the beginning, but about 1400 mg thereafter.
The treated water with good water quality was obtained even when it was increased to / (maximum 2730 mg /), and the organic substance concentration in the treated water was stable from several mg / to 10 mg / from beginning to end. The removal rate did not change even one year after the start of the experiment.

This indicates that the activator used in the experiment is excellent in the ability to remove organic substances and its sustainability.

(2) Initially, the volume load was started at 0.5 kg-BOD / m ³ · day, but the load could be increased up to 17 kg-BOD / m ³ · day. Volume load 17kg-BOD /
Even under a high load condition of m ³ · daY, the organic matter concentration in the treated water was maintained at 10 mg / or less, and the dissolved oxygen in the fluidized bed at this time could be kept at 6 mg / or more.

This indicates that the fluidized bed filled with this activator has a sufficient organic matter removing ability even under a high organic matter loading condition.

(3) The pH of the treated water initially showed a slightly high value due to the alkali content eluted from the particles of the activator, but the microorganisms adhere to the surface of the particles, the load increases, and
It came to settle in the range of 7.5.

This indicates that it is not necessary to replenish the artificial wastewater with an alkaline component, that is, the pH adjustment of the artificial wastewater is unnecessary.

(4) As the load of organic matter increases, the amount of microorganisms retained also increases, but eventually it reached the ceiling. The final microbial retention was 20g, despite being affected by the air supply.
/ We have reached above. The concentration of the microorganisms in the conventional activated sludge aeration tank was 2 to 4 g /, which was 5 to 10 times higher than that.

This indicates that the amount of microorganisms retained by the activator is extremely large, and it can be easily inferred that this greatly contributes to the improvement of the organic substance removal ability described in (1) and (2) above. .

(5) At a microbial load of 24 g / hour, several dozen types of protozoa were confirmed in addition to bacteria. It is considered that this is because the activator in the fluid tank 1 effectively acted on the food chain function between biota.

This indicates that this can further enhance the organic substance removal ability of the activator.

Furthermore, when the high-load fluidized bed was left under anaerobic conditions,
3.2 × 10 ⁹ pieces / ml of red non-sulfur bacteria were isolated. This indicates that it can also be used for cells that are generally difficult to grow, such as nitrifying bacteria.

The above-described manufacturing methods 1 to 3 are examples of using sewage sludge incineration ash having self-hardening property and using obsidian foam powder as obsidian powder. The following production method 4 is an example in which sewage sludge incineration ash that does not have self-hardening property is used, and obsidian foam powder and obsidian crushed material are used as obsidian powder, and production method 5 has self-hardening property. This is an example in which obsidian foam powder and crushed obsidian are used for sewage sludge incineration ash.

The granular solidified products produced by any of the production methods were characteristic in that the compressive strength was significantly increased.

(Production method 4) 50% by weight of sewage sludge incineration ash having no self-hardening property, 42% by weight of Portland cement, 2% by weight of obsidian foam powder,
3% by weight of crushed obsidian and 3% by weight of calcium hydroxide are put in a mixer and thoroughly mixed, and an appropriate amount of water is added to the obtained mixture, and the mixture is kneaded and cured.

The uniaxial compressive strength of the resulting granular solid was purified by production method, 313kgf / cm ² at 203kgf / cm ^2, 28 days Zai齡7 days
Met.

(Production method 5) 50% by weight of sewage sludge incineration ash having self-hardening property, 46% by weight of Portland cement, 1% by weight of obsidian foam powder, and 3% by weight of crushed obsidian were put into a mixer and sufficiently mixed to obtain An appropriate amount of water is added to the mixture, and the mixture is kneaded and cured.

The uniaxial compressive strength of the resulting granular solid was purified by production method, 663kgf / cm ² at 438kgf / cm ^2, 28 days Zai齡7 days
Met.

〔The invention's effect〕

As described above, according to the present invention, (1) the specific gravity surface area is large, and the surface has pores suitable for microorganisms,
(2) The specific gravity can be adjusted, the weight is light enough to easily flow in a fluidized bed, and (3) it has hydrophilicity,
(4) It has a strength such that it does not break in a fluidized bed, and (5) it contains minerals, which are necessary for the growth of microorganisms and are an alkali source necessary for nitrifying ammonia nitrogen in water, which is a nutrient source of microorganisms, into water. It is possible to obtain a microbial activator having a property of eluting and therefore exhibiting an excellent ability to remove organic substances in water and a method for producing the same.

Further, the microbial activator according to the present invention utilizes its physical and chemical properties, and uses other than the microbial activator, for example, mortar, lightweight aggregate for concrete, binder instead of cement, roadbed material, water permeability. Materials, water retention materials, breathable horticultural materials, permeable wall materials, gravel contact oxidation materials, sidewalk flat plates, water permeable bricks, lightweight blocks, water storage roadbed materials, flowerpots, gardening planters, water permeable U-shaped grooves , Permeable wastewater pipes, concrete blocks, tetrapods, etc. can be used after being subjected to required processing.

Further, the microbial activation material according to the present invention uses 50% by weight or more of sewage sludge incineration ash as a base material. Therefore, according to the present invention, it becomes possible to recycle the sewage sludge incineration ash, which has conventionally been difficult to treat and dispose. That is,
The effective utilization becomes possible.

[Brief description of drawings]

1 to 3 are micrographs showing the particle structure of pellet-shaped microbial activator according to the embodiment of the present invention, FIG. 1 shows the whole image of the particles, and FIGS. 2 and 3 show 1 is an enlarged view of FIG. FIG. 4 is a block diagram of an external circulation type three-phase fluidized bed used in an organic matter removal experiment conducted on pellet-shaped microbial activator according to the example. 1 ... Flow tank 2 ... Supply port 3 ... Air supply pipe 4 ... Microorganism activation material 5 ... Outflow port

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etsuo Yoneyama 1-2-15 Takigashira, Isogo-ku, Yokohama-shi, Kanagawa Yokohama-shi pollution research institute (56) Reference JP-A-50-124459 (JP, A) Sho 60-143896 (JP, A) JP-A 61-71892 (JP, A)

Claims (2)

[Claims] 1. A microbial activation material using sewage sludge incineration ash, which comprises sewage sludge incineration ash, cement, obsidian foam powder, and / or pulverized solid of obsidian pulverized product and kneaded water. 2. A sewage sludge incineration ash as a base material, to which cement and obsidian foam powder and / or crushed obsidian powder are added and mixed, and water is added and kneaded, and the obtained kneaded material is granulated. A method for producing a microbial activation material using sewage sludge incineration ash, which comprises processing and curing or curing and curing the material into particles.