JP2010099614A - Contact material for water treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact material for water treatment which improves the amount of adhering microorganisms, hardly causes simultaneous peeling of the adhering microorganisms, can be manufactured without complicated processes, and is easy in installation and pulling up work. <P>SOLUTION: The contact material for water treatment is made of knitted fabric. In the knitted fabric, a plurality of ground fabrics formed to have a predetermined width are arranged in a wale direction at predetermined intervals, and threads having a strength of 6cN/dtex or more and threads thicker than those forming the ground fabric are inserted in a course direction and in a wale direction respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a contact material for water treatment. More particularly, the present invention relates to a water treatment contact material suitable for water treatment using microorganisms.

  As a wastewater treatment method for household wastewater, factory wastewater, sewage, and the like, a method called a standard activated sludge method by microbial treatment is performed. However, since there is a limit to the site area and the processing tank capacity of the processing facility, there is a problem in processing stability due to a long processing time due to failure to maintain a high microbial concentration, and processing stability against load fluctuations. In order to solve these problems, it is only necessary to increase the residence time of microorganisms by increasing the concentration of microorganisms in the reaction tank, that is, to keep useful microorganisms in the reaction tank for a long period of time. Therefore, a “carrier-based treatment method” and a “fixed-bed biofilm method” have been developed that do not involve a normal solid-liquid separation process. In these methods, various contact materials are arranged inside an aeration tank which is a treatment tank, and the contact materials are immersed in the water to be treated. In the water to be treated, microorganisms adhere to the contact material, and the microorganisms decompose the organic matter in the waste water to perform water treatment. In this method, since a large amount of microorganisms adhere to the contact material, the microorganism concentration in the treatment tank is apparently increased, and even slow-growing microorganisms are not washed away, so that there is diversity and treatment efficiency is improved.

  Conventionally, as such a contact material, one using a plate-shaped or three-dimensional plastic molded product is known. However, since these have less surface irregularities and a small surface area, it is difficult for microorganisms to adhere to them and it is difficult to efficiently perform water treatment. In addition, there is a defect that microorganisms once attached are easy to peel off, and when a shock is applied to the contact material, the attached microorganisms are peeled off at once and the water quality fluctuates, causing problems such as fluctuations in treatment performance. There is a point.

  Therefore, as the contact material, a non-woven fabric or woven fabric made of monofilament yarn, or a part to which microorganisms are attached as in Patent Documents 1 to 4 is formed by a string-like, tape-like, or mall-like loop. . Since it is thought that the adhesion amount of microorganisms depends on the surface state and surface area of the contact material, a processed yarn such as a crimped yarn or a multifilament yarn is used for the loop. Thereby, although the adhesion amount of microorganisms improves, since the core material and loop which hold | maintain this loop are manufactured separately and integrated, there exists a problem that it is inferior to productivity. Further, even when the core material and the loop are manufactured integrally, there is a problem that, for example, the strength of the core material is not sufficient because the performance required for the core material and the loop is different.

  Further, in Patent Document 5, attachment portions to a frame of a fixed floor are formed at both ends in the longitudinal direction of a warp-like woven fabric composed of a plurality of warps and a large number of wefts, and between adjacent warps. Cut the weft portion in the warp length direction, and twist the warp yarn in the lengthwise direction to give the warp yarn a twist in the length direction. It is easy to manufacture and is attached to the frame of the fixed floor by arranging it in a spiral around each warp and projecting radially from each warp, and holding the state of twist given to each warp with a fixture. A fixed-bed element for water treatment with good workability is disclosed.

  In this contact material, since the wefts are arranged in a spiral shape, the space between the wefts including the microorganisms is appropriately maintained, the amount of attached microorganisms is improved, and further, the simultaneous peeling of the attached microorganisms is eliminated. However, in the manufacturing process of this contact material, the process of cutting the weft yarn along the length of the warp and the step of twisting the warp over the length of the load are loads, and furthermore, the attachment part to the frame of the fixed floor is arranged. After that, the weft yarn of the contact material is cut along the length of the warp yarn, and the twisted state given to each warp yarn is held using a fixture, so that new members and work processes increase, and the contact material becomes expensive. There is a concern that it will become.

  Furthermore, although the contact material using a woven fabric is disclosed in Patent Document 6, this is because the weft yarn is configured in a curved shape that swells outward from the warp yarn, the effective surface area increases, It is described that the contact efficiency is high and the possibility of occurrence of blockage is low.

  In the case of a contact material composed of a woven structure in this way, the wefts intersect perpendicularly with the warp yarns, but there are disadvantages that the weft yarns are easily removed after cutting because there are few entanglement points. Furthermore, since it is a woven fabric, there is a problem that wefts are displaced and it is difficult to maintain the form.

  When the contact material is used for water treatment, it is fixed to the mounting frame of the treatment tank through a rigid pipe, so that the cloth cylindrical parts for passing the pipe are attached to the lower end and the upper end of the contact material. It is necessary to sew together. In the case of the contact material of Patent Document 2, since the warp portion is composed of a woven structure, the sliding resistance when stitched together is small, and when the contact material is used for a long period of time, the load on the sewn portion of the tubular portion is increased. There is a concern that the warp may be unwound or cut when the woven structure of the contact material loses the tension of the sewing thread.

  Further, as a contact material using a knitted fabric, for example, Patent Document 7 discloses a corner in which a plurality of chain knitting yarns arranged in parallel are connected at predetermined intervals by an insertion yarn to form a square gap. In a water treatment contact material made of mesh raschel knitted fabric, the inserted yarn is composed of a plurality of layers of a non-crimped yarn and a synthetic fiber multifilament crimped yarn layer having a crimp elongation of 5 to 30%. A water treatment contact material is disclosed which is characterized in that

  However, when the contact material having such a configuration is suspended in a hook shape and installed, the warp yarn may break due to the weight of microorganisms adhering in large quantities when it is pulled up from the aeration tank at the time of maintenance. For this reason, there is a possibility that the chain structure may be stretched and block the blower device installed on the bottom surface of the aeration tank.

JP 62-97695 A JP-A-1-135593 JP 2000-246276 A JP 2001-104974 A JP-A-7-275880 JP 2002-119990 A JP 62-083094 A

  The present invention has been made in view of the above-mentioned problems, and is a contact material that improves the amount of attached microorganisms and is difficult to peel off the attached microorganisms all at once, and can be manufactured without complicated processes and installed. Another object is to provide a water treatment contact material that can be easily lifted.

  That is, the present invention is a water treatment contact material comprising a knitted fabric, wherein the knitted fabric has a plurality of ground knitted fabrics having a predetermined width arranged in a well direction at a predetermined interval, and is 6 cN / dtex or more. The present invention relates to a water treatment contact material in which a yarn having strength is inserted in a course direction, and a yarn thicker than a yarn constituting a ground knitting is inserted in a well direction.

  The strength of the yarn inserted in the course direction is preferably 6 to 8 cN / dtex.

  It is preferable that the thickness of the thread inserted in the well direction is 1100 to 11000 dtex.

  The knitted fabric is preferably made of warp knitting.

  It is preferable that the ground stitch is composed of a chain structure.

  The width of the ground knitting is preferably 3 to 50 mm.

  It is preferable that a plurality of the ground stitches are arranged in the well direction at intervals of 30 to 200 mm.

  It is preferable that the fibers inserted in the well direction are cut between the ground knitting and the ground knitting.

  According to the contact material of the present invention, since the yarn having a strength of 6 cN / dtex or more is inserted in the course direction, the elongation in the length direction is suppressed, and the installation and the lifting work are facilitated. In addition, it is easy to sew a garment for attachment to a fixed floor. In addition, since the yarn thicker than the ground stitch is inserted in the well direction, the amount of attached microorganisms is improved and the attached microorganisms are difficult to peel off at the same time.

Embodiments of the present invention will be described below.
FIG. 1 shows a configuration example of the contact material of the present invention. In the contact material 8 made of the knitted fabric of the present invention, the ground knitted fabric 1 formed with a predetermined width is arranged at predetermined intervals in the well direction. This ground stitch 1 exists as a core material of the contact material. Further, a yarn having a strength of 6 cN / dtex or more (hereinafter referred to as a reinforcing yarn 2; not shown) is inserted in the ground knitting over the course direction, and in the well direction, the yarn constituting the ground knitting. A thicker thread 3 (hereinafter referred to as a weft insertion thread 3) is inserted.

  The reinforcing yarn 2 inserted in the course direction suppresses the elongation of the contact material in the course direction and increases the strength, which is useful for facilitating installation and lifting work. Further, the weft insertion thread 3 inserted in the well direction serves as a filter medium that increases the amount of microorganisms attached to the contact material or entangles suspended matter.

  The ground knitting 1 that is the core material is preferably knitted with a width of 3 to 50 mm, and more preferably 5 to 20 mm. If the width of the ground knitted fabric 1 is smaller than 3 mm, it tends to be easily cut when installed, and if it exceeds 50 mm, the exposed amount (length) of the weft is reduced and the amount of attached microorganisms is reduced. As described above, when the core material is twisted (twisted) in a spiral shape, a load tends to be applied in the step of twisting (twisting).

  Moreover, it is preferable that the said ground fabric 1 is arrange | positioned at intervals of 30-200 mm, and it is more preferable that the intervals of 60-100 mm are opened. When the distance between the ground stitches 1 is smaller than 30 mm, when microorganisms or suspended matter adheres, they are likely to become clogged and become stick-like, and this may cause poor water permeability. It tends to peel easily. Moreover, when the space | interval of ground fabrics 1 is larger than 200 mm, it exists in the tendency for the weft insertion yarns 3 inserted in the well direction to contact, and to become easy to get entangled.

  Examples of the yarn constituting the ground knitted fabric 1 include monofilaments or multifilaments of synthetic fibers such as polyester, polypropylene, nylon, vinylidene chloride, vinylon, or acrylic, and metal fibers such as copper wires or iron wires. In particular, it is assumed that it is used after being exposed to a harsh atmosphere such as a treatment tank for a long time, and furthermore, considering the stress applied to the contact material, it has durability, corrosion resistance and fastness, A fiber having high tensile strength and low elongation is preferably used, and polyester fiber is more preferable in terms of excellent fastness and durability, and being inexpensive.

  The yarn thickness is preferably 17 to 167 dtex, and more preferably 44 to 84 dtex. If the thickness of the yarn constituting the ground knitting is smaller than 17 dtex, the strength of the ground knitting structure tends to become extremely small. If the thickness exceeds 167 dtex, the running performance is improved when knitting using an 18 gauge knitting machine. Productivity tends to deteriorate due to reasons such as not rising. Further, the strength of the yarn is preferably 3 cN / dtex or more, more preferably 4 cN / dtex or more in that the strength of the knitted fabric can be maintained. The upper limit of the strength is preferably 8 cN / dtex. The higher the strength of the yarn constituting the ground knitting, the better. However, it may be appropriately selected and used in consideration of the balance with the number of gauges of the knitting machine and the cost.

  The knitted fabric is preferably formed by warp knitting. In particular, the ground knitting 1 is preferably constituted by a chain structure in that there are few thread dropouts and fraying.

  It is preferable that 1-2 reinforcing yarns 2 are inserted for each well of the fabric 1. If the number of reinforcing yarns 2 is less than 1 per well of the ground knitted fabric 1, the effect of improving the strength is low, and there is a tendency to break or stretch, and if the number exceeds 2, the cost tends to increase. .

  As the reinforcing yarn 2, fiber types listed as yarns constituting the ground knitting 1 are used, but yarns having higher strength than these are used. In order to increase the strength of the ground knitting 1, a high-strength yarn may be used as the yarn constituting the ground knitting 1, but a yarn having sufficient strength as a contact material generally has high rigidity, and such a yarn It is very difficult to perform knitting using, which reduces productivity. Therefore, in the present invention, sufficient strength is provided without lowering productivity by inserting the reinforcing yarn 2 having higher strength into the ground knitted fabric 1.

  The reinforcing yarn 2 has a strength of 6 cN / dtex or more, and preferably 6 to 8 cN / dtex. Among these, a polyester strong yarn having this strength is more preferable. If the strength of the reinforcing yarn 2 is smaller than 6 cN / dtex, the reinforcing effect is not sufficient and the contact material extends in the length direction. Moreover, since the thing larger than 8 cN / dtex is not mass-produced now, it tends to become high-cost. Moreover, the thickness in particular is not limited, What is necessary is just a thickness which expresses high intensity | strength.

  Further, the weft insertion thread 3 inserted in the well direction is inserted using, for example, a weft insertion raschel machine. Inserting wefts that hold microbes or filter media as insertion yarns that do not directly contribute to the formation of the structure, not as yarns that make up the woven or knitted structure like conventional contact materials made of woven or knitted fabric As a result, the degree of freedom of the yarn type is increased. As will be described later, this yarn is preferably thick and bulky, but such yarn is difficult to weave and knitted. In addition, although the inserted yarn is easy to come off, the contact material of the present invention is made of a knitted fabric, so that there are many entanglement points between the ground knitting and the inserting yarn, and the yarn can be prevented from coming off.

  The weft insertion thread 3 may be inserted in every course, but avoids clogging when microorganisms or suspended matter adheres, resulting in poor water permeability or easy release of them all at once. Therefore, it is preferable to insert partly. In addition, from the viewpoint of increasing the space between the fibers and further promoting the adhesion of microorganisms, weft insertion yarns are continuously several courses so that several weft insertion yarns 3 gather to form tufts 9. 3 is preferably inserted. That is, for example, one weft insertion thread 3 is inserted into each of four consecutive courses, four courses are left, and one weft insertion thread 3 is inserted into each of the four courses.

  At this time, how many weft insertion yarns 3 per course are inserted, how many courses are inserted, and how many courses are opened, as appropriate depending on the thickness and bulkiness of the weft insertion yarn 3 to be inserted. do it. In particular, the weft insertion thread and the weft insertion thread or the distance between the tufts (hereinafter referred to as mesh 4) is preferably 3 to 100 mm, and more preferably 5 to 50 mm. When the mesh 4 is smaller than 3 mm, particularly when this weft insertion thread is cut and used as will be described later, the cut weft insertion threads are likely to come into contact with each other. Problems such as blockage and simultaneous peeling are likely to occur. On the other hand, when the mesh 4 exceeds 100 mm, the weft amount decreases, so that it is difficult to attach an appropriate amount of microorganisms.

  The weft insertion yarn 3 is not particularly limited as long as it is thicker than the yarn constituting the ground stitch 1, and for example, monofilaments or multifilaments of synthetic fibers such as polyester, polypropylene, nylon, vinylidene chloride, vinylon, and acrylic are used. can give. In particular, high-bulk processed yarns such as woolly yarns obtained by false twisting of raw yarns and ultra-fine high multifilament yarns, and thick yarns having a large surface area are preferable. By using such a thread, the porosity and the surface area can be increased, and high microorganism adhesion, microorganism retention, or performance as a filter medium can be ensured.

  The thickness of the weft insertion yarn 3 is preferably 1100 to 11000 dtex, and more preferably 2800 to 10000 dtex. When the thickness of the weft insertion thread 3 is smaller than 1100 dtex, it becomes difficult to secure a sufficient surface area and the amount of microorganisms tends to decrease. When the thickness exceeds 11000 dtex, the tension increases when knitting. Therefore, a load is applied to the knitting machine itself, which tends to cause a problem of productivity efficiency. The strength of the weft insertion yarn 3 is preferably 3 to 4 cN / dtex.

  As shown in FIG. 2, the contact material 8 of the present invention can be used by cutting the weft insertion yarn 3 along a cutting line 7 between the ground knitting 1 and the ground knitting 1. A large number of cut weft insertion yarns 3 project between the ground stitches 1 and can swing in the drainage or the like. When this contact material is installed in a treatment tank of a wastewater treatment facility or the like, a contact material in the form of a string or mesh is applied to a suitable attachment cloth at regular intervals, and both ends of the contact material are attached together with this attachment cloth. A pair of attachment portions 5 to the frame body is formed by sewing with a sewing thread 6 in a cylindrical shape. At this time, the contact material may be deformed and used. The mounting portion 5 is open at both ends, and is fixed in the treatment tank through a pipe or the like.

  Thus, even when the weft insertion yarn is cut and used, the contact material of the present invention has the weft insertion yarn 3 inserted into the ground knitting 1 made of a knitting structure, so that it is more than the case of the woven structure. However, the number of entanglement points increases and the weft insertion thread 3 is difficult to come off. In addition, as shown in FIG. 2, when sewing together with the accessory cloth, the number of contact points between the sewing thread 6 and the ground knitting is larger than that in the case of the woven structure, and therefore, the sliding resistance between the contact material and the attachment portion 5 is excellent.

  In addition, the contact material of this invention can also be used without cut | disconnecting as mentioned above. The conventional string-like contact material is made by weaving and fixing the string-like contact material in a radial manner so that the protruding wefts are in proper contact with each other, and a gap is formed between the yarns to allow microorganisms to adhere. Protruding. However, in order to form this radial weft, new processes and members are required, and the manufacturing process has become complicated. Since the contact material of the present invention uses a thick thread for the weft insertion thread without adding twist or the like, sufficient microbial adhesion can be achieved. Therefore, it can be used without cutting the weft as described above.

  The present invention will be specifically described with reference to examples.

Example 1
A knitted fabric was knitted with the knitting design shown in FIG. 3 using a weft insertion Raschel machine. As the yarn constituting the ground knitting, 84 dtex, 36 filament, 4 cN / dtex polyester yarn was used, the width of one ground knitting was 5 mm, and the distance between the ground knittings was 90 mm. In addition, two polyester yarns of 1100 dtex, 96 filament, 7.9 cN / dtex were inserted as reinforcing yarns into one well of the ground fabric. Polyester wooly yarn of 3000 dtex, 675 filament, 4 cN / dtex was used as the weft insertion yarn. .

  Next, the weft insertion yarn was cut so as to have the same length between the ground knitting and the ground knitting, and a string-like contact material was obtained. The unit weight was 32 g / m. The two string-like contact materials obtained were cut so that the length immersed in the activated sludge in the aeration tank was 28 cm. As shown in FIG. 2, both ends of the contact material were sewn into a cylindrical shape together with a suitable attachment cloth at intervals of 10 cm, and a pair of attachment portions to the frame body was formed. When sewing, no particular twist was added to the string-like contact material.

Comparative Example 1
Commercially available string-like fabric contact purification material (Bio-Fringe, manufactured by NET Corp., warp: polyester, weft: high-bulk processed acrylic fiber, unit weight: about 22 g / m), twisted, and wefts are radial The attachment part installed in aeration tanks, such as a waste water treatment facility, was formed like Example 1 except having sewed so that it might protrude.

<Evaluation of water treatment capacity>
2 sets of contact materials obtained in Example 1 and Comparative Example 1 were each applied to activated sludge 20L in the first aeration tank of Seiren Co., Ltd. TPF factory wastewater treatment facility with MLSS (Mixed liquor Suspended Solid) of about 8000 mg / L. I put it in. The amount of dissolved oxygen was set to about 5 mg / L, and after aeration at room temperature for 5 days, the contact material was pulled up from the aeration tank. Subsequently, it was made to dry at 105 degreeC for 24 hours, and the microorganisms adhesion amount was measured. The results are shown in Table 1.

  From Table 1, it can be seen that the contact material of the present invention has a high microbial adhesion amount and excellent water treatment ability despite no twisting.

It is a schematic diagram which shows the contact material of this invention. It is a model at the time of sewing an attaching part to a contact material. 1 is a production design diagram of Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground stitch 2 Reinforcement thread 3 Weft insertion thread 4 Scale 5 Attachment part 6 Sewing thread 7 Cut surface 8 Contact material 9 Bunch

Claims (8)

A water treatment contact material comprising a knitted fabric, wherein a plurality of ground knitted fabrics having a predetermined width are arranged in a well direction at predetermined intervals, and a yarn having a strength of 6 cN / dtex or more is a course. A water treatment contact material in which, in the direction, yarns thicker than the yarn constituting the ground knitting are respectively inserted in the well direction. The contact material for water treatment according to claim 1, wherein the strength of the yarn inserted in the course direction is 6 to 8 cN / dtex. The contact material for water treatment according to claim 1 or 2, wherein the thickness of the thread inserted in the well direction is 1100 to 11000 dtex. The water treatment contact material according to claim 1, 2 or 3, wherein the knitted fabric comprises warp knitting. The contact material for water treatment according to claim 1, 2, 3, or 4, wherein the ground stitch is composed of a chain structure. The contact material for water treatment according to claim 1, 2, 3, 4, or 5, wherein the width of the ground stitch is 3 to 50 mm. The contact material for water treatment according to claim 1, 2, 3, 4, 5 or 6, wherein a plurality of the ground stitches are arranged in the well direction at intervals of 30 to 200 mm. The contact material for water treatment according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the fibers inserted in the well direction are cut between a ground knitting and a ground knitting.

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