JPH09155385A - Treatment of garbage waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently liquefy and decompose fine raw waste refuse contained in the waste water of garbage ground by a disposer and discharged from a kitchen without producing scum and facilitate the aerobic purifying treatment of org. matter in garbage waste water after liquefying decomposition. SOLUTION: In a garbage waste water treatment method consisting of a liquefying decomposition treatment process, an aerobic treatment process and a sedimentation treatment process, when fine raw waste refuse contained in garbage ground water is liquefied to monomeric matter by anaerobic decomposition bacteria, the part above the almost central part in a liquefying decomposition tank 1 is loosely packed with a large number of carriers composed of polyurethane foam having anaerobic bacteria supported thereon. Garbage ground water containing fine raw waste refuse is passed through the filter bed of the carriers 3 to receive filtering and liquefying decomposition and org. matter in garbage waste water after liquefying decomposition is oxidatively decomposed. At that time, a large number of carriers 6 composed of polyurethane foam having aerobic bacteria supported thereon are floated within an aerobic treatment tank 5 and these carriers 6 and garbage waste water after liquefying decomposition of which the quantity is equal to or more than the total quantity of the carriers 6 are aerated and mixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating kitchen waste water discharged from a disposer after crushing cooked garbage, leftover rice and the like of various food materials with a disposer which is a crusher while adding a small amount of water. .

[0002]

2. Description of the Related Art The liquefaction and decomposition treatment in the conventional kitchen wastewater treatment method requires gentle agitation in the liquefaction and decomposition tank to bring anaerobic microorganisms into contact with solid matter. The scum that surfaced in the area is also crushed. Further, since the anaerobic microorganisms are dilutedly distributed in the liquefaction and decomposition tank, the treatment efficiency is poor, and the retention capacity of the liquefaction and decomposition tank is 50 to 60 days at room temperature (around 20 ° C) and medium temperature heating (35 to 3).
It is about 30 days at 8 ° C).

In the conventional wastewater treatment method for garbage, oxidative decomposition treatment includes activated sludge method and biofilm method (contact aeration). However, in the activated sludge method, the sludge concentration (MLSS) in the aeration tank becomes too high, and it is difficult to separate the treated water from the activated sludge which is a purification microorganism. Further, similarly in the biofilm method, the contact filter medium is severely clogged with sludge, and the filter bed filled with the filter medium needs to be backwashed several times a week, and the maintenance is complicated.

[0004]

Generally, the kitchen wastewater is crushed and discharged from the kitchen with a disposer which is a crusher while adding a small amount of water to the cooking waste and leftover food of various food materials. In particular, the fine solids in the kitchen wastewater contain a large amount of organic matter, so that the BOD value (biochemical oxygen demand), S
Since the S value (amount of suspended solids) is extremely high, it is difficult to treat it with conventional general purification equipment as described above.

From the above point, the present invention efficiently liquefies and decomposes fine garbage contained in the kitchen waste water crushed by the disposer and discharged from the kitchen without generating scum, and the organic matter in the kitchen waste water after liquefaction decomposition. It is intended to provide a kitchen wastewater treatment method capable of facilitating the aerobic purification process of (1), thereby purifying kitchen wastewater having a large pollution load into clear water that can be discharged to a sewer or a river.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a method for treating kitchen wastewater, which comprises a liquefaction decomposition step, an aerobic treatment step, and a precipitation treatment step, in which fine garbage contained in the kitchen waste water is anaerobically decomposed. When liquefying to a low molecule by means of the above, a large number of carriers of polyurethane foam carrying anaerobic microorganisms are gently filled above the center of the liquefaction decomposition tank, and fine raw garbage is placed in the suspended filter bed of this carrier. Garbage crushed water containing is passed, filtered and liquefied and decomposed.

The present invention also provides a kitchen wastewater treatment method comprising a liquefaction decomposition treatment step, an aerobic treatment step, and a precipitation treatment step, in which the organic matter in the kitchen wastewater after liquefaction decomposition is oxidatively decomposed. A large number of polyurethane foam carriers carrying aerobic microorganisms are suspended in the tank, and the carrier and the kitchen wastewater after liquefaction and decomposition in an amount equal to or more than the total amount of the carriers are aerated and mixed. .

Further, the present invention is characterized by comprising the liquefaction decomposition step of claim 1 and the aerobic treatment step of claim 2.

Therefore, according to the present invention, the filter bed is located above the center of the liquefaction decomposition tank, and the polyurethane foam carrier carrying the anaerobic microorganisms floats in the filter bed. Undecomposed solids in the lower part are filtered and trapped in this filter bed. Then, it is liquefied and decomposed by the action of a large amount of anaerobic degrading bacteria on the surface and inside the carrier. For this reason, the generation of scum, which is the greatest weakness of the conventional liquefaction decomposition tank, was completely suppressed.

Further, the polyurethane foam carrier has a water-absorbing ability even when garbage crushed water enters, and since the water level does not rise at a stretch, it has a function of slowly flowing into the adjacent tank and controlling the flow rate. Moreover, since the carrier of the polyurethane foam is gently filled, it can be decomposed without clogging, and microorganisms can easily propagate in the sponge.

The anaerobic microbial growth area is divided into two upper and lower parts of the liquefaction decomposition tank, and each of them is grown and maintained at a high density so that the retention capacity of the liquefaction decomposition tank is about 20 days at room temperature (around 20 ° C). Exerts a sufficient effect.

In the present invention, a large amount of aerobic microorganisms (20,000 to 30,000 P) are stored in the carrier in the aerobic treatment tank.
Since it grows in PM), it has sufficient purification ability even for a high-concentration liquid after liquefaction decomposition. The surface of the carrier is constantly cleaned by aeration and accompanying swirling flow in the tank. Further, since the pollutant components flowing into the aerobic treatment tank are adsorbed inside the carrier, the concentration of suspended substances in the aerobic treatment tank becomes low. Therefore, the gravity settling type sedimentation tank for solid-liquid separation is easy to exert its capacity.

The present invention also relates to a polyurethane foam carrying aerobic microorganisms which is subjected to aeration in the aerobic treatment tank after being liquefied and decomposed by the carrier of polyurethane foam carrying the anaerobic microorganisms in the liquefaction and decomposition tank. Since it is oxidatively decomposed by the carrier, it can be easily decomposed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a wastewater treatment equipment used for carrying out the method of the present invention. In the figure, 1 is a liquefaction decomposition tank, and a carrier outflow prevention mesh 2 is installed horizontally at approximately the center of the liquefaction decomposition tank 1, and the inside of the liquefaction decomposition tank 1 is mixed with the upper anaerobic filter section 1A and the lower part. It is separated into the storage section 1B.

A large number of polyurethane foam carriers 3 carrying anaerobic microorganisms are slowly filled in the anaerobic filter bed 1A. The carrier 3 becomes in a state similar to water and floats.
Carrier 2 has 20 to 50 cells / inch and size 10 to 2
It is made of polyurethane foam having a 0 mm square and an apparent specific gravity of 0.95 to 1.1.

[0016] Then, kitchen waste water containing fine garbage after the garbage from the kitchen is crushed by the disposer into the liquefaction decomposition tank 1 flows in through the inflow pipe 4, and the retention capacity is kept at room temperature (20
Liquefaction treatment is performed in the mixed storage portion 1B in about 10 days and in the anaerobic filter portion 1A in about 10 days and 20 days.

Reference numeral 5 denotes an aerobic treatment tank adjacent to the liquefaction and decomposition tank 1, in which a large number of polyurethane foam carriers 6 carrying aerobic microorganisms are suspended. And
The carrier 6 and the kitchen wastewater after liquefaction decomposition in an amount equal to or more than the total amount of the carrier 6 are aerated and mixed. The carrier 6 has the same structure as the carrier 3.

Reference numeral 7 is an air diffuser provided at the bottom of the aerobic treatment tank 5, and the surface of the carrier 6 is constantly washed by aeration by the air diffuser 7 and the swirling flow in the tank. Reference numeral 8 is a screen for preventing carrier outflow installed between the aerobic treatment tanks 5 and 5. In the figure, 9 is a precipitation tank adjacent to the aerobic treatment tank 5, and 10 is an air lift horn installed in the precipitation tank 9.

[0019]

EFFECTS OF THE INVENTION According to the present invention, the fine garbage contained in the kitchen waste water crushed by the disposer and discharged from the kitchen is liquefied and decomposed by the carrier of polyurethane foam carrying anaerobic microorganisms in the liquefaction decomposition tank. The generation of scum was completely suppressed, and the retention efficiency was improved to about 20 days at room temperature (around 20 ° C). Further, since the high-concentration liquid is purified by the polyurethane foam carrier carrying the aerobic microorganisms, the treatment method can suppress the generation of excess sludge as much as possible. Further, since the fine garbage is liquefied in the liquefaction decomposition tank and then oxidatively decomposed in the aerobic treatment tank, the decomposition treatment can be facilitated. As described above, the present invention is a treatment method for filling and utilizing polyurethane foam as a carrier in the most suitable method in a liquefaction decomposition tank and an aerobic treatment tank in order to efficiently and stably continuously treat kitchen wastewater. It is possible to reduce the size of the equipment, which is much larger than that of technology, and to improve the economical efficiency, and to dispose of the kitchen wastewater, which has a large pollution load, as clear water and discharge it to the sewer or rivers, which can contribute to environmental hygiene.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a wastewater treatment equipment used for carrying out the method of the present invention.

[Explanation of symbols]

 1 Liquefaction decomposition tank 3 Carrier 5 Aerobic treatment tank 6 Carrier 9 Precipitation tank

Claims (3)

[Claims] 1. In a kitchen wastewater treatment method comprising a liquefaction decomposition treatment step, an aerobic treatment step, and a precipitation treatment step, when liquefying fine garbage contained in the kitchen crushed water into low molecular weight by anaerobic decomposition bacteria, The upper part of the liquefaction decomposition tank is gently filled with a large number of carriers of polyurethane foam supporting anaerobic microorganisms in the upper part of the liquefaction decomposition tank, and garbage crushed water containing fine garbage passes through the filter bed in a floating state of the carriers. A method for treating kitchen wastewater, characterized by being subjected to filtration and liquefaction decomposition. 2. A kitchen wastewater treatment method comprising a liquefaction decomposition treatment step, an aerobic treatment step and a precipitation treatment step, which is preferably used in an aerobic treatment tank when oxidatively decomposing organic substances in the kitchen wastewater after liquefaction decomposition. A method for treating kitchen wastewater, characterized in that a large number of polyurethane foam carriers carrying gaseous microorganisms are suspended, and the carrier and the kitchen wastewater after liquefaction and decomposition in an amount equal to or more than the total amount of the carriers are aerated and mixed. 3. A kitchen wastewater treatment method comprising the liquefaction decomposition step of claim 1 and the aerobic treatment step of claim 2.