JPH0523686A - Packing for treating waste water and treatment of waste water utilizing the packing - Google Patents

Abstract

PURPOSE:To increase efficiency in treating waste water, to prevent the generation of sludge and to enhance the BOD removal rate by extruding a heated and melted thermoplastic resin from a nozzle into fibers, piling up the curled fibers, welding the mutual contacts to integrate the fibers and using the obtained porous material to treat waste water. CONSTITUTION:A thermoplastic resin is heated, melt-extruded from a nozzle into fibers, the curled fibers are piled up, the mutual contacts of the fibers are welded, hence the fibers are integrated to give a porous material, and a packing for treating waste water is formed from the porous material. The packing is charged into an aeration tank with the apparent volume of 40-70% and the BOD volumetric load of 0.15-1.20kg BOD/m<3> D. A PP resin which is lightweight and mechanically tough is used as the raw material. The packing 1 is filled in a raw water storage tank 12 and aeration is carried out, and the load of the aeration tank by the standard activated sludge process is reduced and stabilized.

Description

Detailed Description of the Invention

The present invention relates to a wastewater treatment filler and a wastewater treatment method by a contact aeration method using the same.

[0002]

2. Description of the Related Art As a method of treating waste water, there is a sprinkling filter method which has been used for a long time to fix it to a support such as stone or plastic, and an activated sludge method which is now popular. The biggest problem in the activated sludge method is the maintenance of the activated sludge with good sedimentation property, and most of the equipment consumes a lot of energy for this management, but the phenomenon of bulking (expansion) and dispersion is still present. It often occurs, and sludge outflow and accompanying deterioration of treated water are often observed.

In order to improve the problems of this activated sludge method, attempts have been made for a long time to fix the sludge floating in the liquid, such as a fixed body containing bamboo or tree twigs or a plastic net. The rotating disk method (RB) in which the container and the fixed body are rotated to contact oxygen in the air
C, BIO-SURF) and the like have been proposed and put into practical use. However, these attempts have not yet sufficiently improved the problems of the conventional methods, and new methods have been desired.

[0004]

In order to overcome such disadvantages of the conventional methods, the present inventors repeated various studies and experiments as a suitable microbial cell (sludge) immobilization material, and as a result, thermoplasticity was improved. When the synthetic resin is heated and melted and extruded from the nozzle, piled up while curling the Shinoshino, and using the porous material integrated by fusion molding the mutual contacts of Shinoshino, the BOD removal rate is high and sludge management The present invention has been completed based on the finding that there is no need to remove the excess sludge and there is no need to remove excess sludge.

That is, the present invention comprises a porous material in which a thermoplastic resin is heated and melted and extruded from a nozzle, and the fibrous pieces are stacked while curled and the mutual contact points of the fibrous pieces are fusion-molded and integrated. Consists of a filler for wastewater treatment. The present invention further provides a BOD volume load of 0.15 to 1.20K.
Within the range of gBOD / m ³ · D, the above-mentioned wastewater treatment filler is introduced into the aeration tank in an apparent volume of 40 to 7 with respect to the tank.
It consists of a wastewater treatment method by a contact aeration method, which is characterized by inputting 0%.

The waste water treatment filler of the present invention can have various shapes such as a honeycomb shape, a flat shape, and a cylindrical shape. As a raw material, among the thermoplastic resins, polypropylene resin, which is the lightest and mechanically tough, and which is further altered in water or does not contain a plasticizer and does not elute harmful substances such as organic substances in water. It is preferably used. These resins have extremely strong resistance to acids and alkaline organic solvents.

The porosity of the waste water treatment filler of the present invention is 80 to 98%, although it varies depending on the density of the fiber. Since the porosity is large as described above, the effective capacity of the aeration tank is not reduced so much. The diameter of the fiber is about 1 to 2 mm, the specific gravity is about 0.93, and the bulk specific gravity depends on the shape and the fiber density. Further, its compressive strength is high, and it hardly deforms under the conditions of use as a usual water treatment agent. Further, when the load is extremely large, although it varies depending on the density of fibers, it is generally a linear deformation even if it is deformed, and the recoverability is extremely large.

The waste water treatment filler of the present invention is formed by heating and melting the above-mentioned thermoplastic synthetic resin and extruding from a nozzle, stacking the fibrous products in a curled state, and welding and molding the mutual contact points of the fibrous products. Can be manufactured. Since the mutual contact points are formed by welding as described above, they are not separated by the action of bacteria or the like. The one integrated with an adhesive is unstable because the adhesive layer is often peeled off by the action of bacteria.

Further, since the fibrous structure of the filler for wastewater treatment of the present invention has an extremely irregular fold, the flow of the treated wastewater on the surface of the filler is complicated and diversified, and a portion suitable for the attachment of microorganisms. Therefore, the microorganisms start to adhere and grow in these parts, and gradually diffuse and adhere to the vicinity, and the microorganisms easily adhere and grow even under various treated water conditions. Since a regular mesh-like filler is produced under uniform conditions, it is often difficult for microorganisms to adhere to it. Wastewater treatment filler of the present invention, a biofilm of sludge is generated in the mesh, aerobic and anaerobic bacteria propagate there, because the decomposition action and self-digestion action of organic and inorganic substances is performed, No sludge is generated.

The waste water treatment filler of the present invention is added in an apparent volume of 40 to 60% within the aeration layer within a BOD volume load of 0.15 to 1.50 KgBOD / m ₃ · D. The amount of aeration varies somewhat depending on the ventilation device used, effective water depth, and oxygen utilization efficiency, but basically it can be calculated by the following formula. Air volume (Nm ³ / D) = (raw water ^BOD -treated water ^BOD )
^PPM × raw water flow rate m ³ / D × 120 That is, the condition is that 120 times Nm ³ of air is blown in per kgBOD removal amount.

According to the method of the present invention, the secondary and tertiary drainage water,
It can also be suitably used for advanced tertiary treatment (see attached FIGS. 1 and 2). By using for secondary and tertiary treatment and advanced tertiary treatment, it is possible to contribute to reduction of excess sludge, reduction of power cost, stable improvement of treated water quality, and increase of stability against load fluctuation and contamination of toxic substances. Further, by filling the raw water storage tank with the filler of the present invention and performing aeration, the load on the aeration tank can be reduced and stabilized by the standard activated sludge method (see FIG. 3). Further, since the packing material of the present invention is a three-dimensional reticulated filter material, it acts very effectively even in the gas-liquid contact treatment, and can be effectively used for gas cleaning, removal of offensive odors in deodorization towers, cooling towers and the like ( (See FIG. 4). Also, when used for a rotating body in the rotating disk system,
It is possible to reduce the weight and cost of the rotating body and improve the removal rate (see FIG. 5). Furthermore, it is also suitable for the purification of large amounts of running water such as rivers (see Fig. 6).

[0012]

The present invention will be described in more detail with reference to the following examples. Example 1 Using synthetic sewage having the following composition, No. No. 1 (activated sludge method), No. 1 No. 2 (the present invention was carried out by putting the filler of the present invention in a cylindrical shape into a processing tank by 36% by volume) and No. Three
(67% by volume of the filler of the present invention in a treatment tank as a mat
Wastewater treatment (secondary treatment) was carried out by the method of charging and implementing the present invention). The temperature was room temperature (17 to 23 ° C.).

[0013] The composition of the synthetic waste water (ppm) peptone 100 beef extract _{70 KH 2 PO 4 8 NaCl 20} NH 4 Cl 50 FeCl 3 · 6H 2 O 5 glucose 150 (100) sodium acetate _{200 (150) Na 2 HPO 4} · 12H ₂ O 50 KCl 10 MgSO ₄ 7 The above components were dissolved in tap water, the pH was adjusted to 7.0 to 7.2, and freshly adjusted every day. The concentrations in parentheses were used only when the residence time was 24 hours.

The results are shown in Table 1 below.

[0015]

[Table 1]

[0016]

As described above in detail, when the wastewater treatment filler of the present invention is used to perform wastewater treatment, the wastewater treatment rate is extremely high, no sludge is generated, and the BOD removal rate is 9%.
It reaches 9.5 to 100%. Further, according to the present invention, a large amount of high-pressure air is not required as in the case of the activated sludge method, the drainage can be gently rotated with respect to the mesh structure, and each tank can be naturally flowed down. The operation management is easy and the running cost can be greatly reduced.

Further, according to the method of the present invention, drainage becomes alkaline and there is no fear of deteriorating the environment of lakes and rivers.

[Brief description of drawings]

FIG. 1 is a view showing a treatment tank when the present invention is used for secondary and tertiary treatment of waste water.

FIG. 2 is a diagram showing a treatment tank when the present invention is used for advanced tertiary treatment of wastewater.

FIG. 2 is a diagram showing a treatment tank when the present invention is used as a raw water storage tank.

FIG. 4 is a diagram showing a processing tank when the present invention is used for gas-liquid contact processing.

FIG. 5 is a diagram showing a case where the present invention is applied to a rotating body in a rotating disk system.

FIG. 6 is a diagram showing a case where the present invention is used for purifying running water in a river. 1 ... Filler of the present invention 2 ... Secondary treatment tank 3 ...
Tertiary treatment tank 4 ... Raw water 5 ... Treated water 6 ...
Stand 7 ... Air diffuser 8 ... Backwashing air 9 ...
Water channel 10 at the time of flooding ··· Removal lid 11 · · Advanced tertiary treatment tank 12 · · Raw water storage tank 13 · · Gas-liquid contact processing tank 14 · · Rotating body

Claims (2)

[Claims] 1. A drainage treatment filling comprising a porous material in which thermoplastic resin is heated and melted and extruded from a nozzle, and the fibrous products are stacked while curled, and the mutual contact points of the fibrous products are fusion-molded and integrated. Material. 2. BOD volume load 0.15 to 1.20 Kg
Within the range of BOD / m ³ · D, the waste water treatment filler according to claim 1 is introduced into the aeration tank in an apparent volume of 40 to 40.
A wastewater treatment method by the contact aeration method, which is characterized by adding 70%.