JP2013022586A - Oil-containing waste water treatment system using yeast - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and microbiologically treat waste edible oil contained in oil-containing sewage in a grease trap or a sewage treatment tank, installation of which is obligation of food plants and commercial kitchens, without spending time and effort like continuously charging microorganism.SOLUTION: Candida lipolytica, which is a yeast having high oil-decomposition performance, is made to be contained in a cellulosic porous carrier. After the carrier is put into a bag made of nonwoven fabric made of material which does not let the carrier pass through and processed to have a shape of a bag, the bag is sealed to form a porous carrier pack. The porous carrier pack is charged into the grease trap or the sewage treatment layer. A microbubble generator is concurrently used in place of a normal aeration.

Description

    The present invention supplies yeast necessary for decomposing and removing waste edible fats and oils separated and floated in a grease trap or sewage treatment tank into the grease trap or sewage treatment tank in a method that does not require complicated labor. The present invention relates to an oil-containing sewage microbial treatment system that efficiently purifies oil-containing sewage by supplying air into the tank using microbubbles.

  In facilities that discharge large amounts of oil-containing wastewater, such as food factories and commercial kitchens, the sewerage law requires the installation of grease traps or sewage treatment tanks to prevent waste edible oils from flowing directly into public sewers. It is obliged. In the grease trap or sewage treatment tank, oil-containing wastewater containing waste edible fats and oils flows from one side of the liquid tank, and the waste edible fats and oils float in the liquid tank due to the difference in specific gravity. It discharges the gradual oil solution from the other side, and is intended for the physical removal of the edible fat and oil contained in the wastewater. Waste edible oil and sludge accumulated in the grease trap or sewage treatment tank stays in the tank, and the remaining gradual oil is drained to the sewer pipe through the trap pipe.

In general, waste edible oils and fats separated in a grease trap or sewage treatment tank are scooped up with a ladle and collected and disposed as industrial waste. If the separated waste edible oil and sludge are left in the liquid tank, ammonia and hydrogen sulfide, which are degradable components of the oil and fat, are generated by anaerobic microorganisms, causing a severe odor. Moreover, the waste edible oil and oil which flowed out beyond the trap pipe may clog the sewer pipe. The kitchen environment is deteriorated due to bad odors and can cause serious problems in terms of hygiene such as the generation of pests. Therefore, it is generally taken up and disposed of about once a month.

However, since this cleaning work is a dirty work performed in a rotting odor, employees tend to avoid it, and regular cleaning and maintenance are often not performed.
Also, some waste edible oil and fat remains in the gradual oil discharged through the grease trap or sewage treatment tank, and this waste edible oil and fat adheres to the inner wall of the drain pipe and solidifies, clogging the drain pipe. In some cases, wastewater flows backward, and it is very expensive to purify the area contaminated by the backflow wastewater and restore clogged water pipes.

In order to solve the problem of the grease trap, a system for decomposing oil in a liquid tank using a microbial preparation having oil decomposability has been reported. (Japanese Patent Laid-Open No. 2005-230706 Bio-type Grease Trap, Japanese Patent Laid-Open No. 2004-346695 Grease Trap Tank Purification Method and Purification Device)
This consists of a microbial supply device that injects powdered or liquid microbial preparations into the grease trap liquid tank at regular intervals, and an air blower that supplies air into the liquid tank so that the microorganisms can absorb oxygen and be activated easily. It is comprised with the aeration apparatus provided.

However, since the injected microorganisms are washed away by the outflow of the wastewater in the tank due to the inflow of kitchen wastewater, the necessary amount of bacteria must always be injected to maintain the number of live oil-decomposing microorganisms in the tank above a certain level. I must.

Problems to be solved by the present invention

As described above, the present invention eliminates the trouble of constantly injecting microorganisms, and efficiently uses waste edible fats and oils contained in oil-containing sewage in grease traps or sewage treatment tanks that are obliged to be installed in food factories or commercial kitchens The problem is to perform microbiological treatment well.

Means for solving the problem

As a result of intensive studies to achieve the above object, the present invention has been reached, and details will be described below.

The present invention contains a yeast Candida lipolytica having a high oil-decomposing performance in a cellulosic porous carrier, and a porous material formed by sealing the nonwoven fabric made of a material that does not pass through the carrier into a bag processed into a bag shape. By introducing the quality carrier pack into the sewage treatment layer, and by using a microbubble generator in combination with normal aeration, it is not necessary to add yeast frequently every day, It has been found that oil-containing wastewater can be efficiently treated by exchange or yeast supplementation of the carrier.

The highly oil-degradable yeast used in the present invention is Candida lipolytica, and various microorganisms have been examined, and this was the most excellent.

The yeast Candida lipolytica used in the present invention may be in the form of a liquid or a powder, but is preferably a powder product in view of storage stability.

The material of the porous carrier used in the present invention is preferably a cellulose-based material, and it is desirable that the material has an appropriate size and a diameter of 3 mm to 20 mm.

In the present invention, the porous carrier has the characteristics described below when used for the microbiological treatment of oil-containing wastewater containing waste edible fats and oils.
(1) The surface has an adsorption capacity or oil absorption of fats and oils derived from the porous structure. (2) The porous structure functions as a microorganism carrier capable of immobilizing a large amount of sewage treatment microorganisms.
(3) Since the apparent bulk specific gravity is small and it always floats on the sewage surface, it is possible to secure a place suitable for adsorbing waste edible oil on the sewage surface.

The method for producing a yeast-containing carrier in the present invention is prepared by impregnating or spraying a cellulose-based carrier with a required amount of liquid or powdery yeast and uniformly carrying it.

As the material for the non-woven bag used in the present invention, polyethylene, polypropylene, cellulose, polylactic acid, fatty acid-derived polyurethane, and hybrid products thereof can be used. However, it is desirable to have an appropriate organization that does not easily leak into external wastewater.

In this invention, the nonwoven fabric which consists of the said raw material has the characteristic described below, when using it for the microbiological process of the wastewater containing waste edible fats and oils.
(1) Non-woven fabric fiber itself is not completely porous, but has a specific surface area similar to the porous structure by increasing the fiber density per unit pile of non-woven fabric, and adsorbs waste edible fats and oils. Performance can be improved.
(2) It can function as a microorganism carrier capable of fixing a large amount of sewage treatment microorganisms.

In the method for producing a yeast-containing carrier pack of the present invention, the yeast-containing carrier is put into a bag-like unwoven cloth, and then the entrance is sealed by heat sealing, bonding with a fastener (including a hook-and-loop fastener) or an adhesive. That is, in the case of a disposable application, it is sealed with a heat seal or an adhesive, but in the case of reuse, it is sealed with a fastener that can easily replace the carrier and add yeast.

Embodiments of the present invention will be described based on examples, but the present invention is not limited thereto.

Example 1
A microbubble generator is applied to a water tank containing 30 L of simulated waste water (containing edible oil 5,000 mg / L, about 30 ° C.), and our stored oil-degrading Bacillus subtilis (Bacillus subtilis), our stored oil-degrading yeast ( Pichia farinosa) and our stored oil-degrading yeast (Candida lipolytica) were each added with 10 ⁸ viable bacteria / 1 L of waste water, and the change over time in the fat and oil content in the simulated waste water (normal hexane extract substance amount mg / L) was measured. The results are shown in Table-1.
In Candida lipolytica which is our stored oil-decomposing yeast, we confirmed superior oil-decomposing performance.

Example 2
Three types of porous carriers are selected: polyurethane beads (BCN: manufactured by Nisshinbo Co., Ltd.), polyvinyl alcohol (PVA) sponge (Micro Breath: manufactured by Aion Co., Ltd.), and cellulose beads (Visco Pearl: manufactured by Rengo Co., Ltd.). Then, 1 g of each carrier was prepared by adhering 10 ⁸ viable cell counts as the viable cell count of yeast Candida lipolytica.
Separately, a polypropylene nonwoven fabric having a basis weight of 75 g / m ² is processed to form a bag having a width of 170 mm and a length of 300 mm. A bag containing 30 g of a carrier to which the yeast Candida lipolytica previously prepared is encapsulated in this bag is used as a yeast-containing porous carrier pack (perspective view: FIG. 1, sectional view: FIG. 2). Each of the yeast-containing porous carrier packs was placed in a water tank containing 30 L of simulated waste water (containing edible oil 5,000 mg / L, about 30 ° C.), and a microbubble generator was applied to the bottom.
The time-dependent change of fats and oils in the simulated wastewater (normal hexane extract substance amount mg / L) was measured. The results are shown in Table 2. The oil decomposition performance superior in cellulose beads as the carrier material was confirmed.

Example 3
Aeration was compared under different conditions. The aeration conditions to be compared were three conditions: no aeration, use of a general aeration apparatus (HIBLOW HP20: manufactured by Techno Takatsuki), and use of a microbubble generator (YJ nozzle: manufactured by Envirovision). Using the yeast-containing porous carrier pack using the cellulose beads prepared in Example 2 as a carrier, this was installed in a water tank containing 30 L of simulated waste water (containing edible oil 5,000 mg / L, about 30 ° C.), Each aeration apparatus was applied to the bottom.
The time-dependent change of fats and oils in the simulated wastewater (normal hexane extract substance amount mg / L) was measured. The results are shown in Table-3. The oil decomposition performance superior in the one using the microbubble generator was confirmed.

It is a perspective view which shows the Example of the porous support pack of this invention. It is sectional drawing along the (A)-(A ') line | wire of FIG. It is sectional drawing of an Example of this invention.

An embodiment of the present invention is shown in FIG.

1: Unemployed cloth 2: Heat seal part 3: Microorganism carrier 4: Grease trap 5: Strainer 6: Partition wall 7: Trap tube 8: Microbubble generator 9: Blower

Claims (2)

In an oil-containing wastewater treatment method using a pack in which a porous carrier containing yeast with high oil-decomposing performance is enclosed in a non-woven bag,
The porous carrier is porous cellulose particles;
The oil-containing wastewater treatment system, wherein the yeast having high oil-decomposing performance is Candida lipolytica.   The oil-containing wastewater treatment system according to claim 1, wherein a microbubble generator is used.

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