JPS62239983A - Cultivation of yeast with waste water - Google Patents

Abstract

PURPOSE:To increase the amount f recovered microbial cells, by keeping waste water under anaerobic condition for a given period, solubilizing and digesting glucides, filtering the treated solution through a screen to remove residues, treating the resultant filtrate with a yeast and recovering the yeast. CONSTITUTION:Waste water 1 containing much glucides frown a food factory is introduced into a solubilization and digestion treating step 2 subjected to anaerobic decomposition treatment and introduced into a screen treating step 3 to separate undercomposed fibers, etc. The filtrate is then introduced into a yeast treating step 4 kept under slightly aerobic condition by introducing air and fermented. The solution after the treatment is further introduced into a centrifugal separating step 5 and separated into concentrated microbial cells 6 and a supernatant liquid. The concentrated microbial cells 6 are then utilized for a fertilizer, etc. The separated solution after the centrifugal separation is then introduced into a catalytic oxidation treating step 7, subjected to aerobic biological treating step passed through a precipitating step and introduced into a sterilization treating step 8 to carry out disinfection in a chlorine disinfection vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for culturing yeast using wastewater for producing various feeds and fertilizers.

[Conventional technology]

As a known technique for producing feed and fertilizer, for example, as seen in Japanese Patent Publication No. 60-29678, livestock cords are completely solubilized and digested to generate all organic acids, and then yeast is cultured to produce feed and fertilizer. There is a way to manufacture everything.

[Problem that the invention seeks to solve]

j≠＞i′i1P consolation r's small bite can IF? The feed and fertilizer used for the cattle were often contaminated with inert SS, so their protein content was low and their commercial value was low.

The present invention aims to provide a complete method for culturing yeast using wastewater, which yields a large amount of bacterial cells and reduces contamination with inactive SS.

[Means to solve all problems]

In the present invention, wastewater is maintained in an anaerobic state for a predetermined period (for example, 1 to 2 days) to solubilize and digest it. After that, the entire treated liquid is filtered through a screen and the residue is removed. Remove. This is a method for culturing yeast using wastewater, in which yeast is recovered by treating the filtrate with gold yeast.

[Effect]

The present invention is a method of solubilizing and digesting wastewater, then removing all the residue using a screen, and culturing yeast in the treated solution. In addition, the screen treatment reduces the amount of inert SS mixed in.

〔Example〕

The entire process sequence of the method for culturing yeast using wastewater according to the present invention will be explained below with reference to FIG.

First, food factory wastewater 1 containing a large amount of carbohydrates is used as wastewater.

Next, the wastewater 1 is introduced into the total solubilization and digestion step 2.

In this solubilization and digestion step 2, the wastewater 1 is maintained in an anaerobic state at about 30° C. for about 24 to 48 hours in a solubilization and digestion tank. As a result, the wastewater 1 undergoes primary anaerobic decomposition, and organic acids are removed. In addition, solid carbohydrates and the like are decomposed and liquefied. Therefore, BOD increases and SS decreases.

Next, the next treatment after the above solubilization and digestion treatment fi? Introduced to screen treatment step 6.

In this screen processing step 6, for example, the mesh width is about 0.3.
The treated liquid is filtered through a 1 uI 8 degree fine screen to separate undecomposed fibers and other inorganic substances such as SS. After the screen is washed with treated water, it is dehydrated using a screw press to remove the residue. Note that the dehydrated residue may be incinerated, or may be mixed with concentrated bacterial cells and used as fertilizer or the like. It is also good to introduce it into the washing waste water or the screw press separation t14 next yeast treatment step.

Next, the screen-treated filtrate whole yeast treatment step 4
to be introduced.

In this yeast treatment step 4, the filtrate is introduced into a reaction tank kept microaerobic by introducing air and fermented.

At this time, if the pH of the filtrate is in the range of 3.0 to 8.5, it is fermented as is. In addition, the BOD load is 3゜OKf
The fermentation temperature is approximately 15-25℃.
Adjust to. And, at the beginning of operation, 5 ach & rom
yces, L) ebaryomyces, Hans
Yeasts of the genus enula, genus Torula, genus Pichia, etc. are inoculated, but after that, they are returned.

Next, the treated liquid after the yeast treatment is introduced into the centrifugation step 5.

In this centrifugation step 4, the treated liquid is introduced into a centrifugal separator and separated into concentrated bacterial cells and a supernatant.

At this time, since yeast is relatively uniform in particle size of approximately several tens of microns, it can be effectively separated by a centrifuge. The separated and concentrated bacterial cells 6 have a paste-like appearance with a water content of about 80 to 90%.

Note that a vertical centrifuge 11 as shown in FIG. 2 is suitable as the centrifuge. This vertical centrifugal separator 11 allows the processing liquid to flow from the processing liquid inlet 12 through the entire processing liquid inlet pipe 16 into the bottom of the rotary pole 14, and to be separated from the separation plate 16 provided on the rotary pole 14. The concentrated HA and the separated liquid B are separated into the concentrated iA, the separated liquid B and the fully rotating pole 1.
The liquid is allowed to flow out from the concentrated liquid outlet 17 and the separated liquid outlet 18 at the upper end of 4.

Note that the concentrated sludge obtained in the above centrifugation step is used as it is as liquid fertilizer or the like. Concentrated bacterial cell 6 has a high protein content of about 60% (40-70%) and vitamin content of 0.
Since it contains 0.04% (0.03-0.05%), it has almost the same value as commercially available yeast extract, and is used as fertilizer and feed.

For example, surplus yeast can be very effective when used as a medium for growing mushrooms.

About 10 times the amount of water is added to the excess yeast (sludge), boiled for 2 to 3 hours, and filtered or left to stand to obtain the above ii'. This supernatant liquid is added to the medium as yeast extract. The amount of protein added to the medium is approximately 0.1 to 0.4%. Further, depending on the components of the wastewater, surplus yeast may be directly collected from the yeast treatment process and boiled.

Target mushrooms include enoki mushrooms, which can be cultivated artificially;
Shimeji, Maetake, Nameko, and Shiitake.

Pine mushrooms are nice.

Mushrooms belong to the basidiomycete (fungi) and therefore require a medium for growth. For the growth of basidiomycetes, yeast extract and
Glucose medium, Ebios glucose medium, Epiosto,
Like sugar medium, yeast extract and Ebios (yeast powder) are used. However, these extracts are very expensive and cannot be used to cultivate mushrooms for commercial confectionery, so they are generally used instead of whole mushrooms such as konuka.

However, according to the present invention, since an inexpensive yeast extract can be obtained, it can be used in a culture medium to obtain high-quality mushrooms at a high yield.

On the other hand, the separated liquid obtained in the above centrifugation step is introduced into the catalytic oxidation treatment step 7.

In this contact oxidation treatment step 7, the separated liquid is subjected to aerobic biological treatment in a contact oxidation treatment tank. Here, aeration is performed intermittently, and the inside of the contact oxidation treatment tank repeats anaerobic and aerobic conditions, so that denitrification treatment is also performed.

Further, the contact oxidation treatment tank is filled with a contact filter material such as a corrugated plate, as in the usual case, and a circulating flow is generated in the tank by aeration. In addition, even if the anaerobic process is completely stopped, is it still possible to stir it with another stirring device? You can go there, or you can run out of air. Further, instead of the catalytic oxidation treatment, all normal activated sludge treatment may be employed.

Finally, the liquid gold treated after the catalytic oxidation treatment is introduced into the sterilization treatment step 8 after the precipitation treatment.

In this sterilization treatment step 8, the treatment solution is introduced into the total chlorination tank and disinfected by the injected chlorine.

In addition, so that the residual chlorine of the treatment liquid is 1 to 1 or more,
Typically, chlorine is injected at a rate of about 15jψ-cl/l.

A part of the sterilized liquid 9 after the sterilization process is
The yeast is returned to the yeast treatment step 4. Since yeast is more resistant to oxidizing agents such as chlorine than bacteria, the above-mentioned return suppresses the growth of general bacteria during fermentation.

The following table shows examples of the present invention, and from a wastewater treatment amount of 1.000 m'/day, concentrated bacterial cells of 450 K
? - 7 days dry matter (moisture content 80-90%) was obtained.

Further, the protein content was 60% (40-70%) and the vitamin content was 0.04%.

Although the embodiments of the present invention have been described above, various effective modifications can be made based on the technical idea of the present invention.

For example, the optimal target wastewater is high-11 degree wastewater, breadmaking wastewater (sugar, starch), confectionery wastewater (starch,
olive tang, pectin), ham manufacturing wastewater (oil, fat, protein)
In addition to food factory wastewater such as , hotel and kitchen wastewater (oil and fat), human waste, livestock manure, etc. can be used.

Further, regarding the yeast treatment, a method in which the yeast is suspended or a method in which the yeast is immobilized on a carrier may be used. As the carrier, zeolite, soft ceramics, diatomaceous earth, etc., which can be used directly as feed or fertilizer and are stable, are preferable.

Also, determine the yeast to be used depending on the type of wastewater, and during acclimatization, are these yeasts? It is preferable to culture it separately and add it.

That is, for human waste and livestock manure, (,:andida
The genus Saccharomyces, the genus Debaryomyces, the genus HansenuAa, the genus 'L'orula, and the genus Pichia are used for sugar waste liquid (bread making, confectionery), and the genus Saccharomyces, the genus Debaryomyces, the genus 'L'orula, and the genus Pichia,
For hotels, kitchen waste), Candida spp., L.
Yeasts of the genus Jebaryomyces are preferred.

Further, when the concentrated image is used as liquid fertilizer, it is preferable to use a floating method without adding a carrier.

In addition to centrifugation, bacterial cells can be separated from the yeast treatment solution by
A membrane, gravity concentration, etc. may also be used.

Also, 1! When using whole condensed bacteria as feed, bran, okara,
It is preferable to add defatted soybeans, zeolite, etc. to completely adjust the moisture content. In the case of fertilizer, it is preferable to add zeolite, diatomaceous earth, humus, peat moss, etc. In addition, these final products can be pelletized if necessary.

〔Effect of the invention〕

According to the method for culturing yeast using wastewater of the present invention, most of the solid organic matter in the wastewater is liquefied by the solubilization and digestion treatment, so that a large amount of bacterial cells can be recovered.

In addition, the solids that could not be liquefied by solubilization digestion are removed by screen treatment, and the bacteria obtained by yeast treatment have a high purity and a high protein content, and can be used as feed, fertilizer, etc. It has a high commercial value.

[Brief explanation of drawings]

'Is the $J1 diagram the process 11 of the present invention? The block diagram to be described, FIG. 2, is a schematic diagram showing an example of a centrifugal separator. 1... Wastewater, 2... Solubilization and digestion process, 6...
Screen treatment step, 4... Yeast treatment step, 6.・・・
Concentrated bacterial cells. Patent applicant Nishihara Environmental Health Research Institute Co., Ltd. Patent applicant Nippon Microbial Chemistry Co., Ltd. Figure 1

Claims (1)

[Claims] A method for culturing yeast using wastewater, in which wastewater is maintained in an anaerobic state for a predetermined period of time for solubilization and digestion, the treated liquid is filtered through a screen to remove residue, and the filtrate is treated with yeast to recover yeast. .