JPH0229400B2 - HAISUINOSHORIHOHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating wastewater from food production using flocculating yeast.

The inventor has developed a new treatment method for food manufacturing wastewater using yeast, and has demonstrated that food manufacturing wastewater with high concentrations and large load fluctuations can be efficiently treated by yeast treatment alone or by combining yeast and activated sludge treatment. revealed. [Yoshizawa: Agriculture, 55,
705-711 (1981)] The main point of wastewater treatment using yeast is to maintain a yeast density of 10 ⁸ /ml or more, but depending on the conditions, lysis or predation by microorganisms other than the added yeast, etc. The target yeast may not be able to maintain a yeast density of 10 ⁸ /ml or more due to factors such as competition for nutrients in the wastewater with bacteria and contamination with other yeasts.

Therefore, as a result of intensive study on a method to keep the desired yeast at a stable density, we decided to select and use flocculating yeast as the yeast for wastewater treatment.
They discovered that high yeast density could be maintained and completed the present invention.

The present invention will be explained in detail below.

The flocculating yeast Hansenula anomala J224 (Feikoken Bibori No. 7671) used in the present invention is isolated from the drainage ditch of a sake manufacturing factory, and contains polysaccharides such as starch, sugar alcohols such as glycerol, and lactic acid. It has the ability to assimilate and decompose a wide range of organic substances such as organic acids and amino acids, and includes rice washing wastewater that contains large amounts of polysaccharides such as starch, liquor distillation wastewater that contains large amounts of glycerol and organic acids, pickle wastewater that contains large amounts of lactic acid, etc. It can be used not only for food manufacturing wastewater, but also for industrial wastewater treatment using oils and fats with a high glycerol content as raw materials.

The mycological properties of the flocculating yeast shown as an exemplary strain in the present invention are as follows.

Wort medium (25°C, 3 days culture): Cells form spheres, oval and elongated shapes, films, and sediments.

Wort agar medium (17℃, 1 month): Forms gray smooth or dry white fungal moss Slide medium: Elongated cells connect and form pseudohyphae Ascospore: Vegetative cells directly form ascus Nari, 2
Forms ~4 cap-shaped spores Fermentability of sugars: glucose, sucrose, maltose fermentation, galactose weak, raffinose not fermented at all.

Assimilation of carbon sources: glucose, galactose, sucrose, maltose, cellobiose, trehalose, raffinose, melezitose, soluble starch, L-arabinose, ethanol, glycerin, erythritol, mannitol, α-
Assimilates methyl-D-glucoside, salicin, DL-lactic acid, succinic acid, and citric acid.

L-sorbose, lactose, inulin, D
- Does not utilize xylose, D-ribose, L-rhamnose, ribitol, and inositol.

Nitrate assimilation: Yes Vitamin requirement: None Growth at 37°C: None Growth in 10% saline medium: Yes It completely matches the Hansenula anomala described in "Study, 3rd edition" page 173 (1984).

The conditions for wastewater treatment using flocculating yeast include the pH of the wastewater in a wide range of 3 to 8, preferably PH5 or less to prevent contamination by other microorganisms, and the treatment temperature in the range of 10 to 36°C, preferably 15-30℃ is good. Furthermore, other microbial contamination can be more effectively prevented by adding sodium subzinc oxide or sulfite to the wastewater at a concentration of 20 to 30 ppm or 30 to 40 ppm, respectively, every day or every other day.

For flocculating yeast, in addition to processing the bacterial cells as they are,
In some cases, wastewater can be treated more effectively by adhering to or coagulating on the surface of a carrier such as activated carbon or glass beads.

The material of the treatment tank is not particularly limited, but acid-resistant materials are desirable. The treatment tank can be aerated and agitated using an air pump or the like, and in some cases may be agitated using an agitator to improve the aeration effect.

In the case of wastewater containing low concentrations of organic matter, it is possible to bring the water quality below the wastewater standards only by treatment using flocculating yeast, but in the case of wastewater containing high concentration of organic matter, treatment using flocculant yeast and activated sludge method, etc. By using it in combination with biological treatment or physical treatment such as activated carbon adsorption, the space and construction costs for equipment can be significantly reduced compared to when each treatment is used alone.

It is to be understood that the following examples further illustrate the invention and that the invention is not limited to these examples.

Example 1 Add flocculating yeast Hansenula anomala J224 and SO ₂ to 100 ml of rice washing waste water (raw water) at a density of 1×10 ⁸ /ml.
Add potassium metabisulfite to a concentration of 30 ppm and incubate at 25-30℃ in a 500ml Sakaguchi flask.
After shaking for 1 day, let it stand for 10 minutes, suck up as much of the supernatant liquid (treated water) as possible with a pipette, add 100 ml of fresh rice washing waste water to the precipitated flocculating yeast,
It was shaken at 25-30°C for 2 days. Approximately 60 similar processes
Total organic carbon (TOC) of raw water and treated water for consecutive days
was measured and the TOC removal rate was calculated.

As shown in FIG. 1, the TOC removal rate was 57 to 87%, and even after 11 days of treatment, there was no effect on subsequent treatments.

The following method was used to measure flocculating yeast.

Suspend yeast in 0.02M Tris buffer (PH7.6),
Pronase E was added to a concentration of 5 mg/20 ml, and treated at 37°C for 1 hour to defrogate.
The number of viable bacteria or cells was determined using a Coulter counter using a conventional method.

Example 2 Rice washing wastewater was adjusted to pH 4.0 with hydrochloric acid and left overnight to precipitate most of the starch.The supernatant was used as raw water (TOC 330 ppm) and treated with flocculating yeast for 106 days in the same manner as in Example 1.

The TOC of treated water is 150ppm as shown in Figure 2.
(COD equivalent: 120ppm) or less, and the pH rose to 6.2 to 6.8, making the water quality meet the wastewater standards based on the Prime Minister's Office Ordinance.

Example 3 Whiskey distillation waste liquid (TOC18300ppm) 100ml
Add flocculating yeast to 1×10 ⁸ /ml,
After treatment in a Sakaguchi flask at 30°C for 2 days and standing for 10 minutes, the TOC of the supernatant decreased to 10,200 ppm.

Example 4 Flocculating yeast was suspended in 10 ml of distilled water to a concentration of 5×10 ⁸ /ml, 10 mg of powdered charcoal was added, and the suspension was shaken for 1 minute, resulting in 98% of the yeast adhering to the powdered charcoal. After removing the supernatant liquid, acid precipitation supernatant liquid (PH
4.0, TOC 254 ppm) was added and the supernatant liquid was left at 30°C for 2 days, and the TOC was 49 ppm.

[Brief explanation of drawings]

Figures 1 and 2 show the results of successive treatments of rice washing wastewater and its acid-precipitated supernatant with flocculating yeast, respectively.

Claims (1)

[Claims] 1. A wastewater treatment method characterized by treating food manufacturing wastewater, etc. with a flocculating strain belonging to Hansenula anomala to remove organic matter contained in the wastewater.