JPS6158205B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flocculant that promotes flocculation of water-floating substances, such as activated sludge and sludge, by adding and mixing them when the water-floating substances are separated by filtration. Conventionally, chitosan, curchloric acid, phosphoric acid, chitin, melanin, annose, etc. have been used as the flocculant, but in the present invention, monosaccharides or polysaccharides are used as raw materials, and an acidic nitrogen source is added thereto to achieve pH4. It is characterized by fermenting an organic acid under aerobic conditions using filamentous fungi belonging to Penicillium such as Penicillium spocrisporium in the following culture medium, and using the bacterial bodies separated from the fermentation liquid as a flocculant. It is something. The fermentation production of the organic acid is carried out as follows. The filamentous fungi belonging to Penicillium, such as Penicillium and Spicrisporium, that are used are isolated from soil, etc., and this strain has been deposited at the Institute of Microbiology, Agency of Industrial Science and Technology, with deposit number No. 8727 (formerly deposited). No. 65), Ministry of International Trade and Industry Fermentation Research Institute, Deposit No. 65). PH control of media using monosaccharides and polysaccharides as raw materials is
This is done by adding an acidic nitrogen source such as ammonium chloride, ammonium sulfate, ammonium phosphorus, or ammonium acetate. using various nitrogen sources
The relationship between the PH value and the amount of bioacid when the PH value is controlled is shown in the table below, and the maximum amount of bioacid exists in the range of acidic and strongly acidic conditions below PH4.

[Table] Inorganic salts can also be used to control pH,
Add KH ₂ PO ₄ and MgSO ₄ .7H ₂ O. If about 0.2% of cornstarch liquor is used as a nitrogen source, the addition of inorganic salts can be reduced or not added at all. In addition, although it is possible to produce a raw acid using only sugar and inorganic salt without adding cornstap liquor, the fermentation speed is improved by adding about 0.05%. Other heavy metals
Addition of about 0.005% FeSO ₄ also has a positive effect on the fermentation rate. Next, regarding the sugar concentration and aerobic conditions of the culture medium, the more aerobic the culture, the better the bioacid, and the sugar concentration is 10%.
It is better if it is below that level. When the aeration rate is low or the sugar concentration is too high, the yield of bioacid decreases and ethanol formation occurs instead. If the aeration rate is increased, the sugar concentration will be 10
It may be more than %. From this point of view, fermentation can be carried out while supplementing sugar during culture, making it possible to charge a high concentration (cumulative value) of sugar without reducing the acid yield. Next, examples of fermentation culture will be described. Penicillium spocrisporium Lehmann No. 10 was added to a solution consisting of 10% glycose, about 0.05-0.5% MgSO ₄ +KH ₂ PO ₄ +NH ₄ Cl, and the balance tap water.
Approximately 0.01 to 0.05% of the cultured 1-1 was added, and this solution 100 was fermented and cultured at 30° C. and under rotational vibration at 120 rpm. Organic fermentation was produced after 10 days of culture, and the organic acid was precipitated in the medium together with the bacterial cells in the form of hydrolysis. The organic acids produced in this way have long-chain alkyl groups, carboxyl groups, hydroxyl groups, etc., have both hydrophilicity and lipophilicity, and have a strong adsorption effect on interfaces and surfaces. It has long been known to be useful as a variety of surfactants because it has excellent surfactant effects, such as increasing the wettability of particle surfaces.For example, it is used as a processing fluid for mechanical processing and electrical processing. As a rust preventive agent to be added and mixed in, as a dispersant when mixing and dispersing various particles into grinding paste, detergent paste, or adhesive, as a flaw detection liquid when inspecting the presence or absence of scratches on the surface of hardened parts, etc. It can be used as an additive for paints, various fillers, lubricants, surface protectants, surface purifiers, detergents, soaps, hair washes, pomades, hair tonics, cosmetic creams, coating agents, and the like. As a method for separating organic acids from fermentation liquid, for example, the fermentation liquid is subjected to solid-liquid separation by centrifugation, the solid material consisting of the separated organic acids and bacterial cells is dried, and then the organic acids are extracted with a solvent such as alcohol. A method is used to obtain it by separating it from the bacterial cells. According to this method, in the above example, by centrifuging the fermentation culture solution at a rotation speed of 3600 rpm, the fermentation solution is separated into about 90 separated liquids and a solid substance consisting of organic acid and bacterial cells,
After thoroughly drying this solid matter, we extracted it with alcohol to separate it from the bacterial cells and dried it again, which resulted in approximately 3 kg.
of organic acid and about 0.9 kg of solid bacterial cells were obtained.
The acid obtained in this way is insoluble in water at room temperature, so it can be dissolved in alcohol such as methanol and esterified as an alcohol solution, or dissolved in sodium to make sodium salts such as potassium, calcium, Used as a metal salt such as magnesium. In addition, the separated liquid obtained by solid-liquid separation from the fermentation culture liquid in the above example contains an acid component of about 0.7 to 1
% (quantitative value), and since it is an aqueous solution, it can be used as a rust preventive agent added to the processing fluid as it is. As described above, organic acids produced by fermentation culture are useful as various surfactants, but the present invention aims to utilize the bacterial solids separated and removed from the fermentation liquid, and is useful for research. As a result, the isolated bacterial cells were found to be useful as a flocculant and coagulation-dehydrating agent that promotes flocculation of water-suspended substances in activated sludge, sludge, etc. The flocculating effect is effective not only for anionic flocculants but also for cationic flocculants modified with amines. Furthermore, the organic acid produced by the fermentation also has a flocculating effect, and it is also effective to mix and use the solid bacterial cells and the organic acid. For example, in activated sludge, 50% bacterial solids and 50% sodium salt of organic acid
60ppm of mixed coagulation and dehydration agent to activated sludge liquid.
When mixed and electrolyzed by applying a voltage of 30 V between the Pt anode and graphite cathode, a 0.5 mm thick sludge agglomeration layer was formed on the anode surface in 1 to 2 seconds. The moisture content of this layer was approximately 32%. Furthermore, the SS concentration in the wastewater before this treatment was 1300 ppm, but after the treatment, the SS concentration was approximately 3.4 ppm, indicating an excellent purifying effect. In this manner, in the purification treatment of activated sludge, impurities in water can be coagulated and dehydrated and separated and removed very efficiently, rapidly, and at a high dewatering rate. As described above, the present invention is economically advantageous because, when separating and collecting organic acids from a fermentation culture solution, the bacterial solids that have been separated and removed and have no significant utility value are used as a flocculant. Yes, it has a great practical effect.

Claims (1)

[Claims] 1. Organic acids are fermented under aerobic conditions using filamentous fungi belonging to Penicillium, such as Penicillium and Spicrisporium, in a medium made from monosaccharides or polysaccharides and adjusted to pH 4 or less by adding an acidic nitrogen source. , a flocculant consisting of bacterial cells separated from the fermentation liquid.