JPH05245488A - Vertical parallel type biological membrane purifying apparatus - Google Patents

Abstract

PURPOSE:To increase the amount of bacteria, to prevent the mixing with sludge and to enhance BOD removing efficiency, in an apparatus for the BOD purifying treatment of waste water, by forming internal space having a large number of needle like elements parallelly provided therein in a vertical direction. CONSTITUTION:A purifying apparatus main body 1 is constituted of an upper biological membrane part 2 and a lower activated sludge sedimentation part 3. The biological membrane part 2 is constituted of vertical parallel structures wherein needle like elements are parallelly arranged in a vertical direction at an appropriate interval. The material quality of these structures 4 is not specified but the proper interval between them is about 1cm and determined corresponding to a treatment condition. Water to be treated flows down through the gaps of the structures 4 of the biological membrane part from above to below to be brought into contact with the biological membranes formed on the surfaces of the structures 4 while mixed with air bubbles. The supply of oxygen to the biological membranes is performed by air bubbles added to and mixed with water to be treated and a lower aerator 7.

Description

Detailed Description of the Invention

[0001]

[Industrial application] BOD purification of various wastewater

[0002]

2. Description of the Related Art Wastewater purification apparatuses using microorganisms that are currently used are roughly classified into "activated sludge method" and "biofilm method". The "Activated sludge method" achieves the purpose of purification treatment by propagating and suspending microorganisms (hereinafter referred to as activated sludge) in treated water and stirring and mixing them to bring the treated water and activated sludge into mutual contact. Is the way. The "biofilm method" is a method of performing purification treatment by allowing activated sludge to propagate on the surface of a specific object and giving an opportunity for mutual contact between the object surface and the treated water, and currently used. The following three methods are available. Water sprinkling floor method A biofilm is formed on the surface of an appropriate granular material, and treated water is sprinkled on the laminated structure, and water and the biofilm are brought into contact with each other during the filtration process. Method. Rotating disc method A biofilm is formed on the surface of discs that are arranged in parallel at a suitable interval around a common rotation axis, and the lower half of the discs are immersed in treated water and rotated to produce water. A method of making mutual contact with a biofilm. Suspended particle method A method in which a granular material having a biofilm formed on its surface is suspended and stirred in treated water to bring water into contact with a biofilm. Each of these biological treatment methods described above has the following disadvantages. In other words, the activated sludge method has a limited sludge suspension amount in the treatment tank, so its treatment capacity is low, so a large-capacity treatment tank and sludge separation tank are required, and also a large-scale waterfall equipment and agitation equipment are required. And Since the sprinkling and flooring method causes regular clogging, a backwash stirring device and an activated sludge separation tank accompanying it are necessary to prevent such clogging. The rotating disk method has low power, but the contact efficiency between the disk and water is low, so the processing capacity is low, and a separate sludge separation tank is required. Although the suspended particle method is currently considered to have the highest treatment efficiency, it requires a large-scale water vaporization device and a stirring device similar to the activated sludge method, and requires a large activated sludge separation tank similar to the activated sludge method. Is what you need.

[0003]

On the other hand, the present invention is intended to solve the drawbacks of the above-mentioned methods in the following three points. To develop a means to significantly increase the frequency of mutual contact between treated water and sludge, thereby enhancing its purification capacity and enabling compact activation of the equipment. By not requiring a stirring device at all, it is possible to greatly reduce the power used. To reduce the required area of the entire equipment by completely eliminating the excess activated sludge separation tank.

[0004]

[Means for Solving the Problem] The "biological treatment tank" should be composed of a combination of an upper "biofilm part" and a lower "activated sludge settling part". The "biofilm tank" is composed of vertically aligned structures that are spaced apart from each other, and a biofilm is formed on the surface of the structures. (The material of the structures is not specified, and the distance between the structures is usually about 1 cm.
The treated water flows at an appropriate interval according to the treatment conditions. The treated water flows from the upper part to the lower part or from the lower part to the upper part in the space between the structures of the "biofilm tank", mixing air bubbles in the process of passing through the living organism. It must have a structure that makes mutual contact with the membrane. Oxygen is supplied to the biofilm by a structure in which bubbles are added to the treated water and mixed, and a water vaporizer installed below the biological treatment tank is used.

[0005]

The effects of the biological treatment tank according to the present invention are as follows. We have developed a high-performance device with extremely high purification performance by significantly increasing the biofilm attachment area. That is, a plate with a thickness of 2 mm is 10 mm in a biofilm tank with a volume of 1 m ^3.
Taking an example of a structure in which the structures are arranged in parallel at intervals, the biofilm attachment area of the structure is 166 m ² , and the biofilm thickness is 1.
The total amount of microbial cells when it is 5 mm is about 250 l, which is 1/4 of the volume of the biofilm tank. This is the standard of suspension of organisms in a general activated sludge tank 2000 to 3000 mg / l
This is equivalent to about 100 times that of the fixed type biofilm and the difference in the frequency of mutual contact between the treated water and the biota, that is, the difference in biological treatment capacity. In general, the activated sludge method has a BOD treatment capacity of about 0.5 kg / m ³ / day, whereas this device has a purification capacity of 15 to 20 kg / m ³ / day. If you have it, it will be calculated. The sludge sludge naturally falls through the gap between the tank structures and is collected in the sedimentation tank below. In other words, this prevents sludge from mixing into the treated water, so there is no need to provide a separation tank for treated water and sludge, which is generally an indispensable condition in conventional biological treatment methods. It was possible to eliminate the fear of causing obstruction or clogging. The sludge settled in the settling tank is discharged out of the tank in a timely manner, and after adding a coagulant, it is dehydrated and solidified by a dehydrator. Since it is a fixed biofilm method, it is not necessary to stir the treated water, and the equipment and power required for that purpose are eliminated.

[Brief description of drawings]

FIG. 1 is a side view of a vertical biofilm purification device. FIG. 1 is a model diagram of a flat plate parallel type structure. (Linear parallel type, circular parallel type, and polygon parallel type structure diagrams are omitted).

[Explanation of symbols]

 1 Purification Device Main Body 7 Vaporizer 2 Biofilm 8 Treated Water Overflow 3 Sludge Sediment 9 Treated Water Outflow 4 Vertical Parallel Structure 10 Sludge Discharge 5 Treated Water Inlet 11 Structure Support Rod 6 Air Injection Department

Claims (4)

[Claims] 1. A structure of a biofilm water purification tank characterized in that an internal space is constituted by a large number of needle-shaped bodies arranged in parallel in a vertical direction. 2. The structure of a biofilm water purification tank, characterized in that the inner space is constituted by flat plates or refraction plates that are arranged in parallel in the vertical direction. 3. The structure of a biofilm water purification tank, characterized in that the internal space is constituted by cylindrical bodies arranged in parallel in the vertical direction. 4. A structure of a biofilm septic tank characterized in that a sedimentation separation tank for biological sludge is provided at the bottom of each biofilm water septic tank described above.