JPH0623337A - Treatment of carbage and kitchen waste water - Google Patents

Abstract

PURPOSE:To treat ground garbage without performing solid-liquid separation and recovering the same and to also treat kitchen waste water highest in pollution load among various living water waters. CONSTITUTION:Garbage is ground by a grinder 2 to be washed off by activated sludge water and stored in a storage tank 3. After DO of ground garbage- containing activated sludge water is lowered within the storage tank 3, this sludge water is charged in first and second anaerobic treament tanks 4,7 to accelerate the liquefaction of the ground garbage solid. The liquefied treated water and kitchen waste water are aerobically treated in contact aeration tanks 10A, 10B and sufficiently purified to be discharged. The sludge accumulated in a sedimentation tank 11 is returned to the grinder 2 at the time of the grinding of garbage. At the night when no kitchen waste water flows in, treated water is quantitatively supplied to the second anaerobic treatment tank 7 from the first anaerobic treatment tank 4 by a quantitative pump 16.

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 and kitchen wastewater discharged from a kitchen at home.

[0002]

2. Description of the Related Art Conventionally, there is a disposer as an apparatus for treating garbage, but this alone causes the problem of pollution in the case of discharge to the public water area to discharge crushed garbage with tap water, or the accumulation in the sewer pipe in case of discharge to the sewer, or Due to problems such as a lack of processing capacity at the terminal treatment plant, it has not spread and has reached the present. In other words, in order for the disposer to spread, some treatment should be applied to the crushed kitchen waste to prevent solid contamination,
It is necessary to reduce organic pollution before discharging it to the sewer. As a method for solving this problem, a technique has been developed in which kitchen waste is crushed by a disposer, then solid-liquid separated, liquid is purified by biological treatment, and solid content is methane-fermented to recover energy.

On the other hand, in general households in areas where public waters are released such as Lake Biwa, a single treatment septic tank for purifying human waste and a combined treatment septic tank for purifying domestic wastewater including human waste and household wastewater are installed.

[0004]

However, in the former technique, it is necessary to newly install a solid-liquid separator, and energy recovery by methane fermentation is inefficient unless it is a large-scale treatment facility. There is a problem that it cannot be applied at home and the solid content must be recovered in the end. In addition, most households in the public water area discharge areas are equipped with a single treatment septic tank, and domestic sewage is drained, which is the main cause of eutrophication in public water areas. Therefore, there is an idea to replace the single treatment septic tank currently installed with the combined treatment septic tank, but it is considered to be difficult to realize it in a short time because it costs a lot of money.

The present invention solves the above two problems, and treats crushed kitchen waste without recovery without solid-liquid separation,
Furthermore, the purpose is to treat kitchen wastewater, which has the highest pollution load among domestic wastewater.

[0006]

In order to solve the above-mentioned problems, the present invention utilizes biological wastewater treatment water and excess sludge generated by the biological wastewater treatment water for the transfer of smashed garbage, and performs anaerobic treatment. It is intended to purify by mixing the decomposing water obtained by dissolving and decomposing the crushed garbage in the tank with the kitchen drainage.
Further, at night, the treated water in the anaerobic first treatment tank is supplied in a fixed amount from the anaerobic first treatment tank to the anaerobic second treatment tank.

[0007]

With the above structure, since the biological wastewater treatment water and the excess sludge are used for transferring the waste crushed material, tap water for crushing the waste garbage by the disposer is not required, and the solid content and excess sludge in the kitchen wastewater treatment tank are eliminated. Withdrawal is unnecessary and the processing capacity is improved. In addition, by quantitatively supplying from the anaerobic first treatment tank to the anaerobic second treatment tank at night, the BOD load fluctuation in the anaerobic second treatment tank and the aerobic treatment tank can be reduced and stabilized in the aerobic treatment tank. Organic matter can be removed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a garbage charging port, 2 is a garbage crusher (disposer) for crushing the thrown garbage, 3 is a storage tank for temporarily storing the crushed garbage, 4 is for liquefying the solid waste In the anaerobic first treatment tank, the anaerobic first treatment tank 4 is provided with an anaerobic filter bed 5 for fixing anaerobic bacteria. Reference numeral 7 denotes an anaerobic second treatment tank for treating kitchen wastewater discharged from the sink 6 and kitchen waste liquid water discharged from the anaerobic first treatment tank 4,
It has an anaerobic filter bed 8. Reference numeral 9 denotes a kitchen drainage treatment tank. The kitchen drainage treatment tank 9 includes the anaerobic second treatment tank 7, first and second contact aeration tanks 10A and 10B, and the contact aeration tanks 10A and 10B. A settling tank 11 for settling sludge contained in the water treated in step 1 and a disinfecting tank 12 for disinfecting the supernatant water coming from the settling tank 11 are sequentially provided.

Here, 13 is an air pump for sending air to the air diffuser 14, and 15 is a pump for sending the settled sludge in the second contact aeration tank 10B to the garbage crusher 2. Also, 1
Reference numeral 6 designates the treated water in the anaerobic first treatment tank 4 and the anaerobic second treatment tank 7
It is a metering pump for supplying a fixed amount to, and is operated at night.

The processing flow of kitchen waste and kitchen wastewater in this system is shown in FIG. The garbage thrown in by these systems is finely crushed by the garbage crusher 2 and is made to flow to the storage tank 3 together with the settled sludge water sent from the pump 15. After the DO (dissolved oxygen) is lowered by placing it in the storage tank 3 for a certain period of time, the DO is introduced into the anaerobic first treatment tank 4 so that the DO in the anaerobic first treatment tank 4 is always kept close to 0 and aerobic. Promotes liquefaction of sludge and kitchen solids. The treated water overflowing from the anaerobic first treatment tank 4 and the kitchen wastewater discharged from the sink 6 are subjected to BOD removal in the kitchen wastewater treatment tank 9 and discharged. Furthermore, the treated water in the anaerobic first treatment tank 4 is treated as anaerobic second at night when there is no generation of garbage and kitchen wastewater.
By sending to the treatment tank 7, the BOD load fluctuations to the anaerobic second treatment tank 2 and the aerobic treatment tank (contact aeration tank) are reduced.

Next, the experimental conditions and evaluation method carried out this time will be described. Experimental conditions Effective tank volume Storage tank 10L Anaerobic treatment tank 100L Kitchen drainage day treatment tank 300L Anaerobic filter bed tank 90L Contact aeration tank 170L Precipitation tank 30L Disinfection tank 10L Storage tank residence time 30 minutes Nighttime quantitative supply time and volume AM1: 00
5:00, 2L / hr Target family ... A: Family of 5 (3 adults, 2 children
Name) B: Family of 6 people (4 adults, 2 children) Evaluation method The quality of the discharged water is all evaluated by BOD (biochemical oxygen demand), and it is first used for 2 months before reaching a steady state. After that, the BOD of the anaerobic second treatment tank 7 and the discharged water was measured for 10 weeks every one cycle. As the BOD, a BOD rapid measuring device manufactured by Central Scientific Co., Ltd. was used, and water was sampled 5 times a day at regular intervals, and the average value of the BOD measurement values was taken.
The results are shown below in Tables 1 and 2.

[0012]

[Table 1]

[0013]

[Table 2]

As described above, according to one embodiment of the present invention, the kitchen wastewater is discharged at a BOD concentration of 600 mg / 1, but it can be suppressed to 40 mg / 1 or less, and the garbage can be treated.

[0015]

As is apparent from the above description, according to the present invention, by utilizing the biological wastewater treated water and excess sludge for the transfer of crushed garbage, tap water at the time of crushing garbage by the disposer is unnecessary. In addition, by mixing the decomposed water that has been solubilized and decomposed by anaerobic treatment of kitchen waste and the wastewater from the kitchen, and then purifying the wastewater, the removal of solids and excess sludge from the wastewater treatment tank in the kitchen becomes unnecessary, and the processing capacity is improved This makes it ideal for kitchen wastewater treatment in areas where a single-treatment septic tank is installed, and it is convenient because it eliminates the need to carry out kitchen waste. In addition, due to the constant supply of treated water from the anaerobic first treatment tank to the anaerobic second treatment tank at night, BOD load fluctuations in the anaerobic second treatment tank and the aerobic treatment tank provided downstream of this Can be made small, and stable removal of organic substances is possible in the aerobic treatment tank.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a kitchen waste and kitchen wastewater treatment system according to an embodiment of the present invention.

[Fig. 2] Processing flow chart of kitchen waste and kitchen wastewater by the same system

[Explanation of symbols]

 2 Garbage crusher 3 Storage tank 4 Anaerobic first treatment tank 7 Anaerobic second treatment tank 10A, 10B Contact aeration layer 11 Precipitation layer 12 Disinfection tank 16 Metering pump

Claims (3)

[Claims] 1. A kitchen waste that is treated by using biological wastewater treatment water and excess sludge generated by the biological wastewater treatment water to transfer the crushed garbage, mixes it with the crushed garbage and then puts it in an anaerobic treatment tank. Processing method. 2. A method for treating kitchen waste and kitchen wastewater, which comprises mixing decomposed water obtained by solubilizing and decomposing a crushed kitchen waste with anaerobic treatment and kitchen wastewater, and then purifying the waste. 3. A kitchen waste and a kitchen wastewater in which the treated water from the anaerobic first treatment tank for liquefying the kitchen waste solid matter is supplied to the kitchen wastewater and the anaerobic second treatment tank for treating the treated water in a constant amount at night. Processing method.