JPS6227096A - Microorganism holding body - Google Patents

Abstract

PURPOSE:To obtain a microorganism holding body which improves the adherence of microorganisms having weak adhesive activity and can efficiently and stably attain a waste water treatment by mixing a nutrient, microorganisms, enzyme, coenzyme, foaming agent and surface active agent, etc. with a plastic material. CONSTITUTION:<=1 kinds among the nutrient (e.g., glucose), microorganisms (e.g., nitrifying bacteria), enzyme (e.g., catalase), coenzyme (e.g., thiamine), foaming agent (e.g., sodim carbonate) and surface active agent (e.g., sodium alkyl sulfate) are mixed with the plastic material. The mixing ratio of the compound agents is preferably 1-10pts.wt. by 100pts.wt. The resultant microorganism holding body provides the high rate of the initial adhesion and growth of the microorganism films, the high density of the microorganism films, the strong and stable adhesive force of the microorganisms and the high activity of the microorganism films. Namely, said body contributes to the improvement of the adherence of the microoganisms having the weak adhesive activity and to the efficient and stable execution of the waste water treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a microbial support, and more particularly to a microbial support useful for biochemical treatment of wastewater.

(Prior technology) Conventionally, microbial retainers (filling materials, contact materials, etc.), which are the core of the functions of biological sanitation methods, such as the trickling filter method, contact oxidation method, and rotating disk method in the biochemical treatment of wastewater, have been used. It has many excellent properties such as being biologically and chemically stable (excellent in water resistance and corrosion resistance), being lightweight, having excellent mechanical strength, and being easily molded into desired shapes. Plastic plates, sheets, films, etc. are often used because of their low cost and low cost.

(Problems to be solved by the invention) In aerobic treatment of wastewater, in the case of wastewater with high BOD concentration,
In the case of wastewater with a high rate of biodegradation, microorganisms such as bacteria and protozoa are highly active and have a strong adhesion to the microbial support, so there are no particular problems with using plastic microbial support. . However, B.
Wastewater with a low ODI of 11 degrees (BOD approximately 50 ppm or less)
In the case of methane fermentation treatment, chemical industrial wastewater, or aerobic treatment, the growth rate of microorganisms such as bacteria ψ involved in the treatment is slow, and the activity of the microorganisms is weak. There were many problems, such as difficulty in performing efficient processing and slow start-up of processing functions.

(Means for Solving the Problems) The present invention solves the conventional problems regarding the adhesion and growth of microorganisms as described above, and allows for low i9 degree BOD per water application without losing the excellent properties of plastics. Starting with,
A microorganism that is useful for treating wastewater that normally has a slow microbial growth rate and low microbial adhesion activity, that is, it can improve the adhesion of microorganisms with weak adhesion activity and achieve efficient and stable wastewater treatment. The object is to provide a holding body.

The gist of the present invention which achieves the above object resides in a microorganism carrier comprising a plastic material mixed with one or more of nutrients, microorganisms, enzymes, coenzymes, blowing agents, and surfactants.

The present invention will be explained in detail below.

The holding body of the present invention can be plate-shaped, sheet-shaped, film-shaped, rod-shaped,
It may be in various shapes such as lumps and chips.
The plates, sheets, and films that are shaped like a plate, sheet, or film may be in the form of a corrugated plate, as well as a simple flat one, or those with uneven parts, which are known as microbial carriers. It may have a complex surface morphology.
The rod-shaped material may also have a surface structure such as a concave portion or a convex portion.

The holder of the present invention uses a material in which at least 111 of nutrients, microorganisms, enzymes, coenzymes, foaming agents, and surfactants are uniformly mixed with the above-mentioned plus snack material by mechanical stirring.

The mixing ratio of the above compounding agent to the plastic material is 10
1 to 10 for 0 (hereinafter, parts represent parts by weight)
part is a preferred range. If it exceeds 10 parts, there is a risk that the physical properties of the microorganism carrier will deteriorate, and it is also uneconomical. Moreover, if it is less than 1 part, the wastewater treatment effect will be reduced.

The above mixture may be molded according to conventional plastic molding methods such as extrusion molding, injection molding, calendar molding, and vacuum molding.

Plastic materials serving as the base material of the microorganism carrier of the present invention include polyvinyl chloride, polyethylene, boria pyrene, polyvinylidene chloride, polyamide, polyurethane, and the like.

The nutrient used in the present invention is one that becomes a nutrient for microorganisms that adhere to the holder of the present invention and biochemically decompose pollutants in the wastewater when the holder of the present invention is used to treat wastewater. Specifically, substances that are highly degradable by microorganisms, such as glucose, glutamic acid, sodium acetate, and citric acid, and substances that facilitate the metabolic cycle of microorganisms are used, but they are difficult to decompose at the molding temperature. Things are good.

Next, when the holder of the present invention is used for wastewater treatment, the microorganisms used in the present invention are of the same type as the microorganisms that adhere to it and biochemically purify pollutants in the wastewater. , which acts as a core and activates the reproduction of microorganisms, and also serves as a nutrient source for the microorganisms that adhere and propagate. Enzymes and coenzymes also serve as nutritional sources for attached microorganisms.

-F Microorganisms, enzymes, and coenzymes are preferably those that are difficult to decompose at molding temperatures, but even if they decompose, they can be converted into nutrients and used.

Specific examples of microorganisms include dried bacterial cells such as BODM bacteria, nitrifying bacteria, and methanogenic bacteria, and examples of enzymes include:
Examples include α-glucosidase, saccharase, phosphatase, catalase and the like.

Coenzymes include riboflavin, niacin, thiamin, pyridoxine, biotin, pantothenic acid, folic acid,
Examples include B vitamins such as cobalamin.

Next, the foaming agent used in the present invention increases the surface area of the holder of the present invention and improves the adhesion of microorganisms during biochemical treatment of wastewater.

The blowing agent used may be either an inorganic blowing agent or an organic blowing agent, and one that foams at the molding temperature is selected.

Further, a foaming aid may be used in combination, if necessary.

Specific examples of blowing agents include inorganic blowing agents such as sodium hydrogen carbonate and azides (calcium azide, etc.), organic blowing agents such as azo-type (azobisisobutylnitrile, azodicarbonamide, etc.), and hydrazine-type (diphenyl). sulfone-3,3'-disulfohydrazine, etc.), triazole-based (5-morpholyl-1,2,3,4-thiatriazole, etc.), N-nitroso-based (N,N--dinitrosopentamethylenetetramine, etc.) Examples include.

Furthermore, the surfactant used in the present invention is to improve the adhesion of microorganisms when the holder of the present invention is used for wastewater treatment, and a surfactant that is less toxic to the attached microorganisms is used. For example, anionic and nonionic surfactants are suitable.

Specifically, examples of anionic surfactants include alkyl sodium sulfate, secondary alkyl sodium sulfate,
2-sulfosuccinic acid dialkylamide etc. are selected,
Examples of the nonionic surfactant include alkyl polyoxyethylene ether, fatty acid polyhydric alcohol ester, fatty acid polyhydric alcohol polyoxyethylene, fatty acid sucrose ester, and the like.

(Example 1) 100 parts of polyvinyl chloride resin powder with an average degree of polymerization of 800,
(:, 3 parts of glutamic acid fine powder as a nutritional agent was added to 2 parts of a-Zn stabilizer and 2 parts of lubricant and thoroughly mixed, and this was formed into a sheet by calendering.

Using the thus obtained holder of the present invention, a microbial adhesion test mainly consisting of nitrifying bacteria was conducted in a nitrifying bacteria culture tank.

Artificial wastewater containing mainly ammonium chloride was used as the water to be treated, and the nitrogen concentration was adjusted to 200 ppm. For culture strip A1, the artificial wastewater was adjusted to 20°C and p 1-17 to 8, and the test method was to add a regular filler for culturing nitrifying bacteria to the bottom of the treatment tank and acclimatize it. When the nitrifying bacteria have sufficiently grown on the filler and the treatment performance is stable, the holder of the present invention is immersed in the upper part of the treatment tank, and on the 15th and 30th day, the holder is was lifted, and the amount of microorganisms retained (wet weight) on each holder was measured 1 minute later. The results are indicated by reference numeral 1 in FIG.

(Example 2) 100 parts of polyvinyl chloride resin powder with an average degree of polymerization of 800,
After adding and mixing 2 parts of a Ca-Zn stabilizer and 2 parts of a lubricant with 2 parts of dried bacterial cells of microorganisms (nitrifying bacteria) and 1 part of a coenzyme (vitamin B), the mixture was molded using a calendar method. It was molded into a sheet.

Using the obtained sheet-like material, a microbial adhesion test was conducted under the same raw water and test conditions as in Example 1, and the results are shown by reference numeral 2 in FIG.

(Example 3) 100 parts of polyvinyl chloride resin powder with an average degree of 800,
After adding and mixing 2 parts of a nonionic surfactant (equal mixture of alkyl polyoxyethylene ether and fatty acid polyhydric alcohol ester) as a compounding agent to 2 parts of Ca-7n stabilizer and 2 parts of lubricant, this was calendered. It was molded into a sheet by the method.

A microbial adhesion test was conducted using the 1q sheet-like material using the same test raw water and test conditions as in Example 1, and the results are shown by reference numeral 3 in FIG.

(Example 4) Polyvinyl chloride resin powder 100 with an average degree of polymerization of 1,300
3 parts of a foaming agent (azodicarbonamide) was added as a compounding agent to 50 parts of a plasticizer, 3 parts of a Ca-Zn stabilizer, and heated and foamed to prepare a soft film.

Using the obtained foamed film, a microbial adhesion test was conducted using the same test raw water and test conditions as in Example 1, and the results are shown by reference numeral 4 in FIG.

(Comparative Example) For comparison with the holder of the present invention, 2 parts of Ca-Zn stabilizer and 2 parts of lubricant were added and mixed to 100 parts of the polyvinyl chloride resin powder with an average degree of polymerization of 800 used in Example 1 above. This was then processed into a sheet using a calendar molding method.

The sample raw water and test conditions were set in the same manner as in Examples 1 to 4, and the test results are shown by reference numeral 5 in FIG.

In Figure 1, the vertical axis is the amount of microorganisms retained (wet weight 1?ra/
m2), and the horizontal axis is the number of immersion days (days).

From these results, it is clear that the microorganism carriers of the present invention all have a significantly larger amount of microorganisms retained than those of the comparative examples.

(Effect of the invention) The microorganism carrier of the present invention has the following effects.

(1) Initial adhesion growth method of microbial film [fast.

(2) High density of microbial membrane.

(3) The adhesion of microorganisms is strong and stable.

(4) The microbial membrane is highly active.

[Brief explanation of drawings]

Figure 1 shows the number of days (days) of immersion in the microorganism carrier and the amount of microorganisms retained (wet ff
FIG. 1 is a chart showing the relationship between

Claims (1)

[Claims] A microorganism carrier made of a plastic material mixed with one or more of nutrients, microorganisms, enzymes, coenzymes, foaming agents, and surfactants.