JPS6283094A - Contact material for treating water - Google Patents

Abstract

PURPOSE:To increase the collection quantity of sludge, by using an insert yarn comprising a plurality of layers, that is a layer of a non-crimped yarn and a layer of a synthetic fiber multifilament crimped processed yarn with crimp elongation rate of 5-30%. CONSTITUTION:A contact material 1 for treating water is constituted of a square hole raschel knitted fabric wherein a large number of chain stitch yarns 2 each having a proper thickness are parallelly arranged and connected at predetermined intervals by insert yarns 3, 3' to form square gap parts 4. As the base material of each chain stitch yarn, a natural fiber of a glass fiber is used. As each insert yarn in the square hole raschel knitted fabric, a non- crimped yarn 3 and a bulky synthetic fiber multifilament crimped processed yarn 3' having crimp elongation rate of 5-30% are used. By this method, the collecting capacity of a suspended substance is enhanced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to a contact material for water treatment installed in an aeration tank of a sewage treatment plant, etc., and a method for removing suspended solids at a spillway during dredging and reclamation work. The invention relates to a pollution prevention material for capturing pollutants.

(Conventional technology) Recently, in biological wastewater treatment such as activated sludge method.

Fixed bed catalytic oxidation methods using biofilms are attracting attention. This fixed-bed catalytic oxidation method involves filling an aeration tank with a contact material to which microorganisms easily adhere, and attaching microorganisms to the surface of the contact material.
This system brings wastewater into contact with air and adsorbs it onto the biofilm that has grown. As a contact material in this case, in Japanese Utility Model Application Publication No. 59-27894, a plurality of chain knitting yarns arranged in parallel are connected at predetermined intervals by insertion yarns to form rectangular voids. A contact material for water treatment comprising a square raschel knitted fabric is disclosed. Furthermore, recently, the surface area of the contact material has been increased to facilitate the attachment of microorganisms, and in order to greatly improve the amount of sludge captured.
Research has been conducted on the use of synthetic fiber multifilament crimped yarn having a crimp elongation rate of 5 to 30% as the inserted yarn.

(Problems to be Solved by the Invention) Such a contact material for water treatment has a rectifying effect on the water flow because the inserted threads in the void are arranged in one direction and there is no weft like the weft of a fabric. The water flow that passes through the voids has little drift, and the adhesion of microorganisms is uniform.Furthermore, because the net is gently swayed by the circulating water flow in the tank, the adhering sludge constantly peels off. This method has many advantages, such as preventing large amounts of sludge from suddenly falling off due to thickening of biofilm. There was a problem that the amount of capture was small. As a countermeasure for this.

It has become possible to increase the amount of sludge captured by increasing the bulkiness of the inserted yarn that forms the voids by using synthetic fiber multifilament crimped yarn with a crimp elongation rate of 5 to 30%. . but.

When installing this contact material for water treatment in an aeration tank.

If crimped yarns are used as insertion yarns in the many voids that make up the knitted fabric, the voids may be greatly deformed when tension is applied during tensioning, resulting in poor dimensional stability and A new handling problem arose in that it came into close contact with the contact material. In addition, various pollution prevention fences have been considered and used over spillways during dredging and reclamation work.
Plain woven fabric is mainly used in the tail part of these,
Because the fabric is dense and does not allow water to pass through, in rivers with flowing water or areas where the tides ebb and flow, sludge will flow out from between the fence and the bottom, riding on the water current, making it ineffective. It has the disadvantage of poor ability to trap suspended solids (SS).

(Means for Solving the Problems) In view of the above points, the present invention uses a non-crimped yarn and a bulky synthetic fiber multifilament S-crimped yarn having a crimp elongation rate of 5 to 30% as the insertion yarn. The object of the present invention is to provide a contact material for water treatment that can capture a large amount of sludge and has good one-dimensional stability.

The contact material for water treatment according to the present invention is made of a square raschel knitted fabric in which a plurality of chain stitch yarns arranged in parallel are connected at predetermined intervals by insertion yarns to form rectangular voids. In contact materials for processing.

The inserted yarn is composed of multiple layers of an uncrimped yarn layer and a synthetic multifilament crimped yarn layer having a crimp elongation rate of 5 to 30%. .

The configuration of the two present inventions will be explained in detail below based on the drawings.

FIG. 1 and FIG. 2 show an example of a contact material for water treatment according to the present invention, and the contact material for water treatment (1) is composed of a plurality of chain stitches configured to have an appropriate thickness. The threads (2) are arranged almost parallel to each other, and the chain knitting threads (2) are interleaved with the inserted threads (3).
), (3') were connected at predetermined intervals to form a rectangular gap (mesh) part (4). It is composed of so-called square raschel knitted fabric.

Materials for the chain stitch yarn (2) of the contact material for water treatment of the present invention include organic fibers such as natural fibers, 9 synthetic fibers, inorganic fibers such as glass fibers, mineral fibers, and metal fibers, or filaments that are a mixture thereof. Each inserted yarn in the square raschel knitted fabric is a non-crimped yarn (3) and a bulky synthetic yarn having a crimp elongation rate of 5 to 30%. fiber multifilamen)! Line processed thread (3
’) is used. In this case, the crimpable insertion yarn (3') is not preferable because if the crimp elongation rate is less than 5%, the filament will have excessive convergence, resulting in a decrease in bulkiness, and the texture will also lose its three-dimensional feel. In addition, if the crimp elongation rate exceeds 30%, the convergence will decrease, the handling will be poor, and the filament will break frequently, especially when the two-knit mesh is used, making it unsuitable. Preferably, the crimp elongation rate is 15 to 25%. It is. The inserted thread (3) is a non-crimped thread.

It is possible to use exactly the same material as the chain knitting yarn (2). The contact material of the present invention is shown in FIG.

Two layers: one layer of uncrimped yarn and the other layer of multifilament crimped yarn.
The insertion thread is composed of a layer or three layers.

Therefore, in appearance, a non-crimped yarn (3) appears or a multifilament crimped yarn appears.

Since the crimped yarn has an appropriate number of loops and walnuts, the fluffing effect of these yarns makes it thick and three-dimensional, which is completely different from conventional net-like contact materials. In other words, the contact material of the present invention uses a non-crimped yarn and a multifilament crimped yarn as the insertion yarn, and the contact material exhibits bulkiness due to the loops and walnuts protruding from the surface of the contact material. There are many areas where the filaments intersect with each other, and therefore, sludge adheres three-dimensionally and the amount captured increases. Furthermore, since it has a multi-layer structure with non-crimped yarn, when the contact material is installed in an aeration layer or over a spillway, the non-crimped yarn provides good dimensional stability. , the contact material does not stretch and does not adhere tightly.

Also, the spacing between each chain knitting yarn (2), that is, the insertion yarn (3
) has a length of 10 to 300 mm, and the spacing between each inserted thread is 5 to 70 mm, and the gap in which they are formed (
4) Individual areas are 0.5 to 200 cfi! It is necessary to prevent the voids (4) from being blocked, and it is preferable that the ratio of the total area of the voids (porosity) through which light passes in the projection view to one knitted fabric area is 5 to 80%. . Furthermore, when capturing suspended solids (SS) at a spillway during dredging or reclamation work, it is necessary to select the material appropriately, especially since the porosity varies depending on the water flow, the particle size of the SS, and its properties.

Figure 3 shows an example of installing a water treatment contact material made of a square raschel knitted fabric according to the present invention in an aeration tank, and shows the longitudinal direction of the chain stitch yarn (2) of the square raschel knitted fabric. 1. For example, using the chain stitch yarn of the selvage of the knitted fabric as the upper edge, support rods are passed through the upper and lower gaps and fixed at appropriate positions with connecting bands (6). The material is placed in an aeration tank (
5) Arrange and install in large numbers on the stand inside. In the figure (
7) is an air blowing pipe for aeration.

Next, the crimp elongation rate according to the present invention is l m g/d for the yarn.
The length when the load is applied is L+, 100mg/d
The length when a load is applied is determined by a linear equation as L2.

L z L 1 Crimp elongation rate (%) = X100 (%) L
.

(Example) Next, a specific example in which the contact material for water treatment according to the present invention is used will be described.

A contact material with the following specifications was installed in an aeration tank as shown in Figure 3 to treat domestic wastewater, and the treatment status was investigated over a period of approximately one year.

The results are shown in Table 1.

Contact material specifications/material for water treatment Chain stitch yarn: Polyester multifilament 1500d/
140f 2 inserted threads: Po') I X ? B crimped yarn (crimped elongation rate 20%) L500d/140f 1 piece polyester multifilament non-crimped yarn 1500d/
140f 1 piece / Form: square raschel knitted fabric (as shown in Figure 1) / Porosity: 45% / Void area: 60I+! /pcs/filling amount (1m width x 1m length) x 10 pieces/n? - Also an aeration tank. For comparison, Table 1 also shows the results of processing in the same manner as described above, except that polyester tire cord yarn (crimping elongation rate: 0%) was used as the insertion yarn.

Treatment results are stable throughout the year, with treated water BOD2
Satisfactory results of less than 0 ■/1 and less than 5S20 ■/l were obtained. Furthermore, as a result of observing the state of biofilm adhesion, it was found that the biofilm adhered three-dimensionally to the network structure of the knitted fabric, and there was almost no blockage of the voids. Furthermore, as an effect of the two-layer structure, it was not observed that adjacent contact materials were in close contact with each other.

(Effects of the Invention) The contact material for water treatment according to the present invention is made of a square raschel knitted fabric in which the inserted yarn is composed of multiple layers of non-crimped yarn and crimped multifilament yarn.

It can be placed very easily in the aeration tank at regular intervals, and is light so that it is easy to handle and transport, and requires little space for storage.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing an example of the contact material for water treatment of the present invention. FIG. 2 shows a schematic cross-sectional view thereof. FIG. 3 is a perspective view showing an embodiment in which the contact material for water treatment of the present invention is installed in an aeration tank. (1): Contact material for water treatment (2): Chain knitting yarn (3): Inserted yarn (non-crimped yarn) (3'): Inserted yarn (crimped yarn) (4): Void (mesh) ( 5): Aeration tank (6): Connection band (7): Air blowing pipe for aeration Patent applicant Uni-tei Riki Co., Ltd. ÷ 9 Procedural amendment dated February 26, 1985 1, Case indication patent application Sho 60-223171 No. 2, Name of the invention Contact material for water treatment 3, Relationship to the case of the person making the amendment Patent applicant address 1-50 Higashihonmachi, Amagasaki City, Hyogo Prefecture Name (45
0) Yu-Tei Riki Co., Ltd. Contact information 541 Address 4-68 Kitakyutabe-cho, Higashi-ku, Osaka Name Ninitei Riki Co., Ltd. Patent Department Telephone 06-281-5258 (Dial in) 4,
Date of amendment order: 56 Drawings subject to amendment. 6. Contents of the amendment As shown in the engraving and attached sheet of the drawing originally attached to the application (no change in content).

Claims (1)

[Claims] (1) A contact material for water treatment consisting of a square raschel knitted fabric in which a plurality of chain knit yarns arranged in parallel are connected at predetermined intervals by insertion yarns to form square voids,
For water treatment, characterized in that the inserted yarn is composed of multiple layers of a layer of uncrimped yarn and a layer of synthetic fiber multifilament crimped yarn having a crimp elongation rate of 5 to 30%. contact material.