JPH05317891A - Filter device - Google Patents

Abstract

PURPOSE:To remove the SS and org. matter, such as BOD and COD, chromaticity and smell in raw water by having a filter medium layer on an upstream side of a raw water passing direction and a catalyst layer on a downstream side and injecting a oxidizing agent in the middle of the two layers. CONSTITUTION:The SS components in the raw water are captured and removed in a filter tank 3 when the secondarily treated water of sewage is supplied as the raw water by a supply pipe 7 into a treating tank 1 and is passed therein in upward current. Microorgansims are generated according to the operation and stuck on the surfaces of the filter media, thereby forming biomembranes. The removal of the soluble BOD components, the removal of ammonia by oxidation, etc., are executed and simultaneously, the capacity to stick the SS components is improved. The raw water is mixed with an oxidizing agent injected in an injection pipe 6 at the time of passing the upper part of the filter medium layer 3. The oxidizing decomposition is activated at the time when the water flows upward in the catalyst layer 4. The COD and chromaticity are removed by the generated O2. As a result, the SS, the org. matter, such as BOD and COD, chromaticity and smells, in the raw water are removed in the one filter tank 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration device, particularly to a filtration device suitable for advanced treatment of sewage.

[0002]

2. Description of the Related Art Conventionally, an upflow or downflow filtration device in which a support layer is provided at the bottom of a tank and a filter layer is provided thereon is known.

[0003]

When advanced treatment of sewage was carried out by this filtration device, it was possible to remove organic substances such as COD and BOD in water, which were derived from SS-like components (COD removal rate was 10%). Further, since a microbial film adheres to the surface of the filter medium that constitutes the filter layer, this may partially remove soluble components in water. However, since the conventional filtration device has a main purpose of removing suspended solids in water, it has a low COD removal rate and can hardly remove chromaticity and odor.

[0004]

The present invention was developed for the purpose of obtaining a filter device capable of removing organic substances such as COD and also removing chromaticity and odor. In a filtration device for passing raw water through the bed, a filter medium layer is provided on the upstream side and a catalyst layer is provided on the downstream side with respect to the raw water flow direction, and an oxidizing agent is injected between the filter medium layer and the catalyst layer. It is characterized by

[0005]

In the illustrated embodiment, 1 is a processing tank, 2 is a packed bed, and the packed bed has a sand filter medium layer 3 in the lower layer, a catalyst layer 4 in the upper layer, and a support layer 5 in the lowermost layer. .. An oxidizing agent injection pipe 6 is provided between the filter medium layer 3 and the catalyst layer 4.
Is provided. The support layer 5 has a layer height of about 500 mm, the filter medium layer 3 has a layer height of about 300 mm, and the catalyst layer 4 has a layer height of 100 mm.
It is about 0 mm, and the height of these layers is appropriately determined according to the water quality of the raw water to be treated and the filtration rate. In addition, the catalyst constituting the catalyst layer 4 is made of zeolite, Ni, Co, Fe
A metal having a backwash property capable of carrying a metal such as the above and being distinguishable from the filter sand constituting the filter medium layer 3 is used. The oxidizing agent supplied to the middle of the filter layer 3 and the catalyst layer 4 through the injection pipe 6 is NaOC.
1, NaClO ₂ , H ₂ O and the like.

When the secondary treated water of the sewage is supplied as raw water to the treatment tank through the supply pipe 7 and is passed through in an upward flow, the SS component in the raw water is captured and removed by the filter medium layer 3. In addition, microorganisms are generated during the operation and adhere to the surface of the filter medium to form a biofilm, so that soluble BOD components are removed and ammonia is removed by oxidation. At the same time, the SS removal performance is also improved. It is expected that this is because the attachment ability of the SS component was improved by the attachment of the biofilm.

When passing through the filter medium layer 3 upward, the raw water is mixed with the oxidant injected in the injection pipe 6, and when it flows upward in the catalyst layer 4, the oxidative decomposition is activated by the catalyst and generated. CO ₂ and chromaticity are removed by O ₂ . Although an upflow filtration device has been described in this embodiment, a downflow filtration device may be used. In this case, the filter medium layer is the upper layer and the catalyst layer is the lower layer.

The experimental results of treating the secondary treated water of a certain sewage treatment plant with the filtration device of FIG. 1 are shown below. Ni-supported zeolite catalyst layer is 200 m in a 25 mm diameter column.
m, the filter medium layer was filled with 130 mm and the support layer was filled with 25 mm, and water was passed at a water flow rate of 17.5 ml / min. Sodium hypochlorite was used as the oxidizing agent, and the addition amount was 10 mg / stand. Water quality analysis results Raw water Filtration device of the present invention Filtration device for sand only SS (mg / vertical) 9.5 1.0 0.9 Chromaticity (degree) 21 4.3 20 COD (mg / vertical) 8.2 5. 5 7.1 As is clear from the above, the removal rate of SS is almost the same as that of the sand-only filter, but the COD removal rate is good, and especially the chromaticity cannot be removed by the sand-only filter. On the other hand, the device of the present invention showed a dramatic removal rate.

[0009]

According to the present invention, organic substances such as soluble COD which cannot be removed by sand filtration can be removed. Also, chromaticity that cannot be decomposed by biological treatment can be removed. By providing the filter medium layer and the catalyst layer in the same processing tank, it is not necessary to provide each layer in a separate tank, and the processing apparatus becomes compact. Further, the SS component, COD, chromaticity, etc. can be removed at the same time. Further, a biofilm adheres to the surface of the filter medium layer, and this biofilm removes BOD components and ammonia.
Since SS components, ammonia, and the like consume the oxidant, by removing them in advance, the utilization rate of the oxidant is improved and the injection amount is also reduced. Then, the oxidizer is a filter medium layer,
Since it is injected in the middle of the catalyst layer, it does not impede the function of the biofilm formed in the filter medium layer.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a filter device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Treatment Tank 2 Packing Layer 3 Filter Medium Layer 4 Catalyst Layer 5 Supporting Layer 6 Oxidizing Agent Injection Pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C02F 3/06

Claims (1)

[Claims] 1. A filtration device for passing raw water through a packed bed for filtration, wherein the packed bed has a filter material layer on the upstream side and a catalyst layer on the downstream side in the raw water flow direction, A filtering device characterized in that an oxidizing agent is injected into the middle of the catalyst layer.