JPH0135277Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a contact material for water treatment installed in an aeration tank. (Prior Art) Recently, among biological wastewater treatments such as activated sludge methods, fixed bed catalytic oxidation methods that utilize biofilms have been attracting attention. This fixed-bed catalytic oxidation method involves filling an aeration tank with a contact material to which microorganisms can easily adhere, and bringing the wastewater into contact with air to oxidize the biofilm that grows epiphytically on the surface of the contact material, and then performs adsorption treatment. It is a system that As a contact material in this case, as disclosed 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 through-holes. A contact material for water treatment is disclosed, which is made of a square mesh mesh fabric. (Problems to be solved by the invention) This type of contact material for water treatment has a rectifying effect on water flow, and because the water flow passes through the pores, there is less unbalanced flow and the adhesion of microorganisms is uniform. Furthermore, because the net is gently shaken by the circulating water flow in the tank, the adhered sludge is constantly peeled off, and the biofilm does not thicken and large amounts of sludge suddenly fall off. However, since the sludge adheres to the mesh portion of the net in a planar shape, there is a problem that the amount of sludge captured is small. (Means for Solving the Problems) In view of the above points, the inventors of the present invention conducted intensive research with the aim of providing a contact material for water treatment that can capture a large amount of sludge. The inventors have discovered that the above object can be achieved by using a bulky synthetic fiber multi-filament crimped yarn having a crimp rate of 1.5%, and have completed the present invention. That is, the present invention provides a contact material for water treatment consisting of a square ratchet mesh fabric in which a plurality of chain stitch yarns arranged in parallel are connected at predetermined intervals by insertion yarns to form rectangular through-holes. , the inserted thread is 5~
This contact material for water treatment is characterized by being a synthetic fiber multifilament crimped yarn with a crimp rate of 30%. Below, the configuration of the present invention will be explained in detail based on examples. FIG. 1 shows an example of the contact material for water treatment according to the present invention.
is a plurality of chain knitting yarns 2 composed of appropriate thickness.
are arranged almost parallel to each other, and their chain knitting yarns 2
It is composed of a so-called square-mesh lattice mesh fabric in which square holes (mesh) are formed by connecting the holes at predetermined intervals with insertion threads 3. Materials for the chain stitch yarn 2 of the contact material for water treatment of the present invention include, for example, organic fibers such as natural fibers and synthetic fibers, inorganic fibers such as glass fibers, mineral fibers, and metal fibers, or filament-like or mixed fibers of these fibers. Spun yarn-like yarns can be selected and used as needed, but each inserted yarn 3 in the square mesh ratcelle net fabric is a bulky synthetic fiber multifilament crimped yarn having a crimp rate of 5 to 30%. It is necessary to use In this case, if the crimp ratio is less than 5%, the convergence of the filament will be excessive and the bulkiness will decrease, and the appearance will become planar, which is undesirable.If the crimp rate exceeds 30%, the convergence will be poor The crimp rate is unsuitable because it has poor handling properties and frequently breaks the filament especially during knitting, and the crimp rate is preferably 15 to 25%. The contact material of the present invention is composed of an inserted yarn made of the multifilament crimped yarn, but since the crimped yarn has an appropriate number of loops and sagging, the fluff effect of these yarns makes it difficult to use the conventional multifilament crimped yarn. It has a thickness and three-dimensional properties that are completely different from the net-like contact material. In other words, the contact material of the present invention uses a multifilament crimped yarn as the insertion thread, and the contact material exhibits bulkiness due to loops and sagging that protrude from the surface of the contact material, and the portion where the multifilaments intersect. Therefore, sludge adheres three-dimensionally and the amount of trapped sludge increases. In addition, the spacing between each chain knitting yarn 2 is, for example,
10 to 70 m/m, and the area of each of the through holes 4 in which they are formed is, for example, ² to 200 cm2, which is suitable for preventing the through holes 4 from clogging, and the mesh area It is preferable that the ratio of the total area of the through-holes 4 to the total area (porosity) is 20 to 80%. Fig. 2 shows an example of installing the contact material for water treatment made of square mesh ratchet mesh fabric in an aeration tank according to the present invention, in which the longitudinal direction of the chain knitting yarn 2 of the square mesh mesh fabric is shown. This contact material is used in the horizontal direction, for example, using the chain knitting yarn of the selvage of the net fabric as the upper edge, passing support rods through the upper and lower through holes, and fixing it with the connecting band 6 at the appropriate position. A large number of them are arranged and installed on a pedestal in the aeration tank 5. In the figure, 7 is an air blowing pipe for aeration. Next, the measurement of the crimp ratio in the present invention will be explained in detail. The crimp rate indicates the degree of crimp in the yarn.
Take out the crimped thread from the pack cage to a length of about 1 m.
Measure the trial length L after 1 minute under a load of 0.1 g/d,
After dehydration by developing crimp in boiling water for 30 minutes in a free state, and air drying for one day and night under standard conditions, a load of 0.1 g/d was applied to the sample, and the length L1 was set after 1 minute. After leaving it free for 3 minutes, 2mg/
The test length L2 is measured after 1 minute under the load of d, and the crimp ratio can be calculated from these measured values using the following formula. Crimp rate (%)=L1-L2/L1×100 (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 2, and domestic wastewater was treated, and the treatment status was investigated for about one year. The results are shown in Table 1. Contact material specifications for water treatment Materials: (1) Chain stitch yarn: Polyester multifilament (2) Insert yarn: Polyester crimped yarn (crimp rate 20
%) Form: Square ratchet net (Fig. 1) Porosity: 50% Perforated area: 6 cm ² / piece Filling amount: (1 m width x 1 m length) x 10 pieces / m ³ - Aeration tank Also, for comparison Therefore, Table 1 also shows the results of processing in exactly the same manner as above, except that polyester tire cord yarn (crimping rate: 0%) was used as the insertion yarn.

【table】

[Table] The treatment results are stable throughout the year for both the examples and comparative examples, with treated water BOD of 20mg/or less,
Satisfactory results were obtained with less than 30mg of SS, but
As a result of observing the adhesion status of biofilm, in the example,
The biofilm adheres three-dimensionally to the network structure of the net fabric, whereas in the comparative example it adheres flatly.
The amount of sludge attached was smaller than in the example. (Effects of the invention) Since the contact material for water treatment of the present invention is made of a square mesh lattice mesh fabric of crimped multifilament yarn, the amount of sludge adhering to it increases.
BOD is further removed. In addition, they can be set very easily in an aeration tank at regular intervals, and are lightweight, making them easy to handle and transport, and require little space for storage.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing an example of the contact material for water treatment of the present invention, and FIG. 2 is a perspective view showing an embodiment of the contact material for water treatment of the present invention installed in an aeration tank. be. 1... Contact material for water treatment, 2... Chain knitting yarn, 3...
Insertion thread, 4...through-hole part.

Claims (1)

[Scope of utility model registration request] In a water treatment contact material made of a square ratchet mesh fabric in which a plurality of chain stitch yarns arranged in parallel are connected at predetermined intervals by insertion yarns to form rectangular through-holes, the insertion yarns A contact material for water treatment, characterized in that it is a synthetic fiber multifilament crimped yarn having a crimp rate of 5 to 30%.