JPH06170386A - Treatment of waste water utilizing excessive sludge of treated water supply equipment line - Google Patents

Abstract

PURPOSE:To enhance the decomposition and removal efficiency of the oil component and BOD component in waste water within a biological treatment tank by treating waste water in a biological reaction tank containing activated sludge to obtain treated water supply and adding excessive sludge discharged at this time to the biological treatment tank of a separate waste water treatment line. CONSTITUTION:When the so-called kitchen waste water used in a bathroom, a washstand or a Kitchen is treated, raw water 6 is introduced into the biological treatment tank 1 of a kitchen waste water treatment line through an oil-water separation tank 7 and an adjusting tank 8 to be subjected to biological treatment while air is sent into the raw water. The treated water 5 treated in the biological reaction tank 2 containing activated sludge of the treated water supply equipment line provided in parallel to the kitchen waste water treatment line is filtered by an ultrafiltration membrane 3 and a part of conc. water 4 is added to the biological treatment tank 1. By adding the conc. water containing the excessive sludge of the equipment line to the biological reaction tank 1 as mentioned above, the removal efficiency of an oil component and a BOD component can be enhanced to a large extent as compared with a case performing biological treatment without adding conc. water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment method using surplus sludge in a water supply facility line, and more particularly to a wastewater treatment method suitable for treating so-called kitchen wastewater used in baths, washbasins, kitchens and the like. It is a thing.

[0002]

2. Description of the Related Art Regarding kitchen wastewater discharged from kitchens with a certain area or more, there are legal restrictions on the quality of wastewater that can be discharged into public sewers, for example, biochemical oxygen demand (BO).
D) Exclusion criteria are set to 600ppm or less, suspended solids (SS) 600ppm or less, and oil (normal hexane extract) 30ppm or less. If the exclusion criteria are exceeded, detrimental measures must be taken. Hotel, department, general building,
In various halls, in order to remove the above-mentioned restricted substances in kitchen wastewater, normally, after removing impurities in the wastewater with a fine screen, the wastewater treatment is carried out by the pressure flotation method, biological treatment method, etc. .

The pressure flotation method is a method in which air dissolved in pressurized water is generated as bubbles by lowering the water pressure, and oil is attached to the air to float and separate the oil, and is most commonly used. This is an abatement method. According to this method, the treated water quality changes due to changes in wastewater,
There is a problem that treatment of sludge generated, odor control, and disposal are very expensive. The biological treatment method includes, for example, contacting wastewater with a pure or mixed culture of bacteria, mold, yeast, algae, etc., or microorganisms of activated sludge such as sewage, industrial wastewater, etc., and aeration of the wastewater to oxidize harmful substances. However, it is basically decomposed, and the catalytic oxidation method and the rotating disk method are used. It is a more effective wastewater treatment means than the pressure flotation method because it is effective in removing oil and BOD components, is easy to operate with no generation of sludge, and has a low operating cost. In particular, microbial treatment performed by fixing microorganisms to the filter medium produces less SS than the method using activated sludge (activated sludge method), and SS600ppm
It is a processing method that can reliably achieve the following regulations.

On the other hand, due to the problem of water supply capacity due to the increase in water usage in large cities, department stores, hotels,
In areas such as various halls where water supply is often used, baths,
It is also practiced to treat kitchen wastewater used in washrooms, kitchens, etc. and recycle it as intermediate water for various miscellaneous water such as flush toilet water.The inventors also treat wastewater by the activated sludge method, We have been studying the water supply system that has the basic process of ultrafiltration of treated water. Installing a sewerage system line in department stores, hotels, various halls, etc. has a great economic effect and is advantageous from the viewpoint of saving water resources, but in this case, generation of excess sludge is unavoidable and excess sludge is There is a problem in that solid-liquid separation must be performed and then discarded as industrial waste. Also, in department stores, hotels, various halls, etc., since the amount of kitchen wastewater greatly exceeds the amount of water for flush toilets and other miscellaneous water that can use the tap water, the kitchen wastewater is used as raw water for the tap water facility line. In that case, it is necessary to discharge the excess kitchen wastewater to the public sewers, and there is no choice but to install a separate wastewater treatment line for that purpose.

[0005]

SUMMARY OF THE INVENTION According to the present invention, when a BOD, SS, oil wastewater treatment line by microbial treatment and a wastewater treatment facility line for treating wastewater in a biological reaction tank containing activated sludge are installed together, BOD, SS , In the process of improving the treatment efficiency of the oil wastewater treatment line and examining the measures to effectively utilize the excess sludge generated in the water supply facility line, the excess sludge is BOD, SS, the biological treatment tank of the oil wastewater treatment line It was made based on the finding that the operating performance of the system was greatly improved, and the purpose was to utilize the excess sludge generated in the sewer system line, and to perform the microbial treatment of the BOD, SS and oil wastewater treatment lines. An object of the present invention is to provide a wastewater treatment method using surplus sludge in a water supply facility line, which further improves the decomposition efficiency of oil and BOD components.

[0006]

[Means for Solving the Problems] A method for treating wastewater using surplus sludge in a water supply facility line of the present invention for achieving the above object is a method for treating wastewater by a biological reaction tank containing activated sludge. By adding the excess sludge discharged from the water treatment facility line to a biological treatment tank of another BOD, SS, oil wastewater treatment line and / or a pretreatment step of microbial treatment in the biological treatment tank, Efficiently decomposing oil and BOD components is the basic characteristic of the structure,
The microbial treatment in the biological treatment tank is carried out by the catalytic oxidation method or the rotating disk method, and the wastewater to the biological treatment tank is the kitchen wastewater, and the microbial treatment in the biological treatment tank is the intermediate treatment before the sewer discharge. These are the second and third characteristics of the invention structure.

When the kitchen wastewater is discharged to the sewer, a wastewater treatment line is installed to keep the BOD, SS and oil content below the exclusion standard as described above, and the microbial treatment in the biological treatment tank is mainly used for the removal of harmful substances. In the present invention, an intermediate treatment is carried out for removing the water removed from the ultrafiltration membrane of the attached water supply facility line, that is, the concentrated water containing the excess sludge by BOD,
In addition to the biological treatment tanks of the SS and oil wastewater treatment lines, the effect of removing oil and BOD components in the intermediate treated water is enhanced to ensure that the exclusion standard is met.

[0008]

Since the wastewater treatment method using the excess sludge in the water supply system line of the present invention has the above-mentioned constitution and function, the excess sludge discharged from the water supply facility line is BO.
D, SS, by adding to the biological treatment tank of the oil wastewater treatment line, capture of oil and BOD components in the biological treatment tank,
Decomposition is significantly accelerated compared to the case where excess sludge is not added.

[0009]

EXAMPLES Examples of the present invention will be described below. Example 1 As shown in FIG. 1, BOD components 110 to 20 were used as raw water 6 in a biological treatment tank 1 of a wastewater treatment line for treating kitchen wastewater.
Water of pH 6.5 to 8.6 containing 0 ppm, SS component 90 to 150 ppm, oil content 45 to 80 ppm was introduced at an inflow rate of 150 l / hr, and the amount of aeration air was 7.2 m ³ / hr and the residence time in the tank was 6 hr. Microbial treatment was performed under the conditions. In this case, treated water 5 treated by the biological reaction tank 2 containing activated sludge in the attached water supply facility line
Filtered through an ultrafiltration membrane (UF membrane) 3 and concentrated water (M
Part of LSS 5000ppm) 4 is added to biological treatment tank 1 of the wastewater treatment line at a rate of 6 l / hr. Reference numerals 7 and 8 are an oil / water separation tank and an adjustment tank installed in each line. Analysis of BOD, SS and oil content in the intermediate treated water when the concentrated water 4 containing excess sludge is added to the biological treatment tank 1 to perform the microbial treatment and when the microbial treatment is performed without adding the concentrated water The values are shown in Table 1.

As is clear from Table 1, when the concentrated water containing the excess sludge in the water supply facility line is added to the biological reaction tank of the wastewater treatment line, the efficiency of removing oil and BOD components is greatly improved. Is recognized. SS increases, but is well below the discharge standard.

[0011]

[Table 1]

[0012]

As described above, according to the wastewater treatment method using the excess sludge in the water supply facility line provided by the present invention, the effect of decomposing oil and BOD components is enhanced, and the regulation is surely lower than the emission standard. Can remove substances,
Excess sludge discharged from the sewer system line can be completely treated.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a main part of an apparatus configuration used in a wastewater treatment method of the present invention.

[Explanation of symbols]

 1 Biological treatment tank 2 Biological reaction tank 3 Ultrafiltration membrane 4 Concentrated water 5 Treated water 6 Raw water 7 Oil-water separation tank 8 Adjustment tank

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masashi Toda 131 Izumizaki, Ichihara, Chiba Sumitomo Chemical Engineering Co., Ltd.

Claims (3)

[Claims] 1. Excess sludge discharged from a water supply facility line for treating wastewater by a bioreaction tank containing activated sludge to form a tap water, and a biological treatment tank of another waste water treatment line and / or
Alternatively, a wastewater treatment method using surplus sludge in a water supply facility line, which is characterized by efficiently decomposing oil components and BOD components in wastewater by adding it to a preceding step of microbial treatment in the biological treatment tank. 2. A method for treating wastewater using surplus sludge in a water supply facility line according to claim 1, wherein the treatment of microorganisms in the biological treatment tank is performed by a catalytic oxidation method or a rotating disk method. 3. The wastewater to the biological treatment tank is kitchen wastewater,
The method for treating wastewater using surplus sludge in a water supply facility line according to claim 1 or 2, wherein the microbial treatment in the biological treatment tank is an intermediate treatment before the discharge of the sewer.