JPH08308569A - Carrier for adhering microorganisms and method for producing the same - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to prevent the loss of the first fiber that contributes to the attachment of microorganisms, and to reduce the variation in the weight of the carrier, so that the yield of the carrier per unit fiber amount is reduced. Provide a carrier for adhering microorganisms which is improved. A web comprising a first polyolefin-based fiber having a high melting point of 50 to 100 denier and a second polyolefin-based fiber having a low melting point of 3 to 20 denier, and a base layer of ^{20 to} 100 g / m ² . Non-woven fabric f ₁
Are bonded by needle punching, the first fibers are bound by melting the second fibers, and the ratio of the first fibers is 30 to 30.
A carrier for adhering microorganisms, which is made of a non-woven fabric in which the proportion of the second fiber is 70% and 70 to 30%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier for adhering microorganisms used in a fixed bed method, a rocking bed method, a fluidized bed method or the like in which a microorganism, particularly an aerobic microorganism, acts on sewage or purified water, and a method for producing the same. is there.

[0002]

2. Description of the Related Art A biofilm method in which microorganisms act on sewage or purified water is a water treatment method using a microbial carrier to which microorganisms adhere. This treatment method is drawing attention because it can increase the amount of biofilm per unit water volume.

As a carrier for adhering to microorganisms used in such a biofilm method, there is one proposed by the applicant in Japanese Patent Publication No. 6-45033.

The carrier T for adhering microorganisms is manufactured, for example, by the following procedure.

(1) Polypropylene fiber having a melting point of 170 ° C. and 80 denier (hereinafter referred to as “first fiber”) and low-density polyethylene fiber having a melting point of 110 ° C. and having a high pressure of 6 denier (hereinafter referred to as “second fiber”) 50% of each is passed through the card and the layer to produce a web W having a width of 3 m shown in FIG.

(2) The obtained web W is adhered with a needle punch, and the porosity is 80% and the weight is 3 as shown in FIG. 7 (b).
A long non-woven fabric F _{1 of} 50 g / m ² , thickness of 3 mm, width of 2.7 m, and length of 50 m is cut and cut into a long cut non-woven fabric F _{2 of} 20 cm in width shown in FIG. 7B.

(3) Then, the long cut nonwoven fabric F ₂ is rolled into a cylindrical shape by a processing device and heat-treated at 130 ° C.
The tubular non-woven fabric F ₃ shown in (c) is used, and this is 5.5 cm in length.
The carrier T for adhering microorganisms shown in FIG. 7 (d) and FIG.
And

By the above heat treatment, the second fibers are melted and the first fibers are bound, and the long cut non-woven fabric F ₂ is rolled into a tubular shape.
The overlapping portions of both widthwise ends of the are also joined by the second fibers.

[0009]

The thus-obtained carrier for adhering microorganisms allows water and air to pass through easily, has a large area for adhering microorganisms, and has good adherence to microorganisms.

However, there are still the following problems.

(1) The conventional carrier T for adhering microorganisms obtained as described above has a structure in which the first fiber is held by melting of the second fiber, and the first fiber has inner and outer surfaces. It is exposed in a raised state.

For this reason, when adjacent carriers T rub against each other due to vibration due to vibration during handling such as packing, transportation of carriers, filling of water treatment tank, or convection of water to be treated during use, when the adjacent carriers T rub against each other, The friction causes the first fibers on the outer surface, which contribute to the attachment of the microorganisms, to fall off, reducing the surface area for the microorganisms to be attached, resulting in poor adhesion of the microorganisms to the carrier.

(2) When the web W is adhered by the needle punch, in the process, the first fiber and the second fiber constituting the web W are entangled with each other and are pulled toward the widthwise central portion side. For this reason, the web W shrinks in the width direction, and the basis weight of both ends of the long nonwoven fabric F _{1 in} the width direction becomes relatively heavier than that in the central portion.

As a result, there is a large variation in the weight of the carrier T obtained by processing the long cut nonwoven fabric F _2. As a result, the yield of the carrier T per unit fiber amount becomes poor.

The above-mentioned phenomenon is not preferable because the surface area of the carrier T on which the microorganisms adhere per unit amount of fiber does not increase due to the increase in the weight of the carrier T per unit volume.

The present invention has been made in order to solve the above-mentioned conventional problems, and (1) it is possible to prevent the first fiber from contributing to the attachment of microorganisms to fall off, and (2) the carrier. It is an object of the present invention to provide a microorganism-attached carrier and a method for producing the same, in which variations in weight are reduced, and therefore the yield of the carrier per unit fiber amount is improved.

[0017]

The carrier for adhering microorganisms provided by the present invention comprises a polyolefin-based first fiber having a high melting point of 50 to 100 denier and a polyolefin-based second fiber having a low melting point of 3 to 20 denier. A web made of fibers and a non-woven fabric as a base layer of ^{20 to} 100 g / m ² are adhered by needle punching, the first fibers are bound by melting of the second fibers, and the ratio of the first fibers is 30 ~
It is made of a non-woven fabric in which the proportion of the second fiber is 70% and the proportion of the second fiber is 70 to 30%.

The method for producing a carrier for adhering microorganisms provided by the present invention includes the following steps (1) to (3).

(1) 30 to 70% of the first polyolefin fiber having a high melting point of 50 to 100 denier and 3 to 3
A step of forming a web with 70 to 30% of a second polyolefin fiber having a low melting point of 20 denier.

(2) The obtained web and 20 to 100 g /
A step of laminating a non-woven fabric as a base layer of m ² and adhering it with a needle punch.

(3) The resulting bonded nonwoven fabric is heated at a temperature lower than the melting temperature of the first fibers and higher than the melting temperature of the second fibers to melt the second fibers and bind the first fibers. The process of doing.

Examples of the polyolefin resin having a high melting point include polypropylene, high-density polyethylene and ethylene-propylene copolymer, and examples of the polyolefin resin having a low melting point include low-density polyethylene and ethylene-acetic acid. There are vinyl copolymers and the like.

The temperature difference between the melting point of the polyolefin fiber having a high melting point and the melting point of the polyolefin fiber having a low melting point is preferably 30 ° C. or more.

The thickness of the polyolefin fiber having a high melting point is set to 50 to 100 denier because the shape retention and mechanical strength of the carrier are inferior when the denier is less than 50 denier, while the surface area of the carrier is more than 100 denier. Because it will be small. Further, the thickness of the polyolefin fiber having a low melting point is set to 3 to 20 denier because, outside this range, the polyolefin fibers having a high melting point cannot be sufficiently bound to each other and mechanical strength as a carrier is high. Because it will be inferior to.

The ratio of the polyolefin fiber having a high melting point to the polyolefin fiber having a low melting point is 30 to 70% in the former case and 70 to 30% in the latter case.
If it is less than 0% and the latter exceeds 70%, the shape retention and mechanical strength of the carrier will be poor, while the former will be 70%.
This is because if the amount exceeds the upper limit or the latter ratio is less than 30%, the binding between the polyolefin fibers having high melting points becomes insufficient and the carrier becomes poor in mechanical strength.

The weight of the non-woven fabric as the base layer is 20 to 100 g.
/ M ² means that if it is less than 20 g / m ² , the fracture is too large during needle punching to prevent the shrinkage, while if it exceeds 100 g / m ² , the cost becomes high. Because.

The nonwoven fabric to be the base layer may be produced by any spunbonding method, although the production method is not particularly limited.

[0028]

[Action]

(1) In the present invention, when the web and the non-woven fabric to be the base layer are overlapped and bonded by needle punching, the first fibers and the second fibers constituting the web are adhered to the non-woven fabric to be the base layer while intertwined with each other.

At this time, the first fiber and the second fiber are pulled toward the center portion in the width direction of the nonwoven fabric due to the entanglement with each other, so that the web tends to shrink. However, since the web is constrained by the same nonwoven fabric, it shrinks only slightly.

Therefore, it is possible to obtain a nonwoven fabric for a carrier having a uniform basis weight. Therefore, the weight of the carrier made of this non-woven fabric does not vary.

(2) The non-woven fabric used in the carrier of the present invention has, for example, a non-woven fabric produced by the spun pond method as a base layer, and the first fiber is adhered to the base layer in a raised state. The bonding strength between the non-woven fabric as the base layer and the first fibers is strong. Therefore, for example, the carrier of the present invention flows due to convection of the water to be treated, and even if it is rubbed against another carrier adjacent thereto, the first fibers that contribute to the attachment of the microorganisms do not fall off.

Therefore, unlike the conventional case, there is no possibility that the adhered surface area of the microorganisms will be reduced and the adherence of the microorganisms will be deteriorated due to the dropping of the first fibers.

[0033]

EXAMPLES A method of manufacturing a carrier T _{1 according to} an example of the present invention will be described below in the order of steps with reference to FIGS.

(1) A polypropylene fiber having a melting point of 170 ° C. and a denier of 80 (hereinafter referred to as the first fiber) and a melting point of 1
At 10 ° C., 6 denier high-pressure method low-density polyethylene fibers (hereinafter referred to as the second fibers) were sprayed at a rate of 50% each onto a rotating wire mesh using an air flow, and FIG.
A web W ₁ having a width of 3 m shown in (a) was manufactured.

(2) Obtained web W ₁ and thickness 0.5
mm, width 3 m, non-woven fabric f ₁ as a base layer of 50 g / m ² ,
As shown in FIG. 1 (a), they are laminated and adhered with a needle punch, and as shown in FIG. 1 (b), the porosity is 80% and the weight is 350 g.
A long non-woven fabric f ₂ having a thickness of / m ² , a thickness of 3 mm and a width of 2.8 m was produced.

The nonwoven fabric f ₁ used as the base layer here is
A sheet-shaped web was made at the same time as fiber spinning using thermoplastic polypropylene, and the web was adhered with a solvent.

(3) The obtained long nonwoven fabric f ₂ was cut into a long cut nonwoven fabric f ₃ having a width of 20 cm shown in FIG. 1 (b),
This was wound into a spiral to obtain a wound body R shown in FIG.
At the time of winding, the nonwoven fabric f _{1 serving as the} base layer was placed outside.

(4) The long cut nonwoven fabric f ₃ drawn out from the wound body R is heat-treated by the processing device K shown in FIG. 3 to have a diameter of 5.5 cm and a length of 50 m shown in FIG. 1 (c). A tubular body f ₄ was cut into a length of 5.5 cm, and
(D), The carrier for microorganism attachment T ₁ shown in FIG. 2 was used.

The heat treatment and cutting referred to here are performed by the processing device K.
The procedure is as follows.

First, the processing device K is shown in FIG.
As shown in FIG. 1, the heating unit 1, the pair of guide members 2 arranged on the introduction side of the heating unit 1, and the cutting mechanism 3 arranged on the extraction side.
And a take-up roll 4.

The heating section 1 has an inner surface having a cylindrical surface, and an outer heating guide tube 6 heated by an electric heating mechanism 5 from the outer surface side, and a cylindrical mandrel 7 disposed therein. Between the outer heating guide cylinder 6 and the cylindrical mandrel 7, there is provided an annular space 8 having a width substantially the same as the thickness of the long cut nonwoven fabric f ₃ .

The ambient temperature of the annular space 8 is formed by the outer heating guide cylinder 6 heated to 130 ° C. and the cylindrical mandrel 7 heated by the ambient temperature, and is approximately 13
It is set to 0 ° C. This temperature is lower than the melting point of the polypropylene fiber described above and higher than the melting point of the high-pressure low density polyethylene fiber.

Since the processing device K is constructed as described above, the long cut nonwoven fabric f ₃ successively drawn from the wound body R is bent by the guide member 2 so that the nonwoven fabric f ₁ is on the outside. While being guided to the annular gap 8, while passing through the annular gap 8, both side edges in the width direction are overlapped and heat-treated.

By this heat treatment, the first fibers are bound by the melting of the second fibers and, at the same time, both side edges of the non-woven fabric f ₃ are bound, and the long cut non-woven fabric f ₃ is tubular. It becomes f ₄ . Then, the tubular body f ₄ is the cutting mechanism 3
Is cut into the carrier T ₁ .

FIG. 2 shows the carrier T ₁ of the example thus obtained. This is a carrier having a structure in which the nonwoven fabric f _{1 as the} base layer is exposed to the outside and the napped first fibers S are exposed to the inside, as shown in FIG.

The basis weight of the obtained carrier T ₁ was almost uniform. Further, when the obtained carrier T ₁ was put into a waste water tank and used, water permeability was good, air permeability was also good, no drop of the first fiber S was observed, and adhesion of microorganisms was good. .

The carrier T ₂ shown in FIG. 4 is prepared by winding the long cut nonwoven fabric f ₃ in the above embodiment into a wound body.
The nonwoven fabric f ₁ to be the base layer is wound so as to come to the inside, and this is applied to the processing device K, heat-treated to form a tubular body, and then cut.

This carrier T ₂ is different from the carrier T ₁ of the above-mentioned embodiment in that the nonwoven fabric f _{1 serving as the} base layer is exposed inside and the first fibers S in the raised state are exposed outside. The effect is essentially the same as the carrier T ₁ .

In the carrier T ₃ shown in FIG. 5, first, the webs W ₁ are laminated on both sides of the non-woven fabric f _{1 which} is the base layer of the above-mentioned embodiment and adhered by needle punching to make a long non-woven fabric, and then,
This was cut into a long cut non-woven fabric, which was then heat-treated to form a tubular body and then cut.

In the carrier T ₄ shown in FIG. 6, first, the nonwoven fabric f ₁ which is the base layer is laminated on both sides of the web W ₁ of the above-mentioned embodiment and adhered by needle punching to make a long nonwoven fabric, and then,
This is cut into a long cut non-woven fabric, which is then heat-treated to form a tubular body and then cut.

The carrier T ₃ of FIG. 5 is a nonwoven fabric f ₁ which is a base layer.
The first fibers S in a raised state are exposed on the inside and outside, and the carrier T _{4 in} FIG. 6 has a structure in which the first fibers S are wrapped in the nonwoven fabric f _{1 serving as the} base layer. Thus, the carrier T ₃ and the carrier T ₄
Is different from the carrier T ₁ of the above embodiment in its layer structure. However, there is no difference in action and effect from the carrier T ₁ .

[0052]

As described above, according to the present invention, since it has the above-mentioned structure, the following effects can be obtained.

(1) It is possible to prevent the first fibers that contribute to the attachment of microorganisms from falling off.

(2) The dispersion of the weight of the carrier is reduced, and therefore the yield of the carrier per unit fiber amount is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a production process of a carrier for adhering microorganisms according to an embodiment.

FIG. 2 is a diagram schematically showing the carrier for adhering microorganisms in FIG. 1 when viewed from the side.

FIG. 3 is a cross-sectional view of a processing apparatus used for manufacturing a carrier for adhering microorganisms according to an embodiment.

FIG. 4 is a diagram schematically showing a side view of a carrier for adhering microorganisms according to another embodiment.

FIG. 5 is a diagram schematically showing a carrier for adhering microorganisms according to another example, as viewed from the side.

FIG. 6 is a diagram schematically showing a carrier for adhering microorganisms according to another example, as viewed from the side.

FIG. 7 is a view showing a conventional process for producing a carrier for adhering microorganisms.

FIG. 8 is a perspective view of a conventional carrier for adhering microorganisms.

[Explanation of symbols]

W ₁ web f ₁ base layer non-woven fabric f ₂ long non-woven fabric f ₃ long cut non-woven fabric f ₄ tubular body T _{1 to} T ₄ carrier for adhering microorganisms S first fiber in raised state

Front page continuation (72) Inventor Yorinobu Tachibana 3-2 Chuo 8-chome, Ami-cho, Inashiki-gun, Ibaraki Mitsubishi Chemical Industrial Co., Ltd. Product Research Laboratory (72) Inventor Chotaro Sugimoto 4-chome Nihonbashihoncho, Chuo-ku, Tokyo No. 2 Mitsubishi Kagaku Co., Ltd. (72) Inventor Sansei Nakamura No. 3-4 Kawaramachi, Chuo-ku, Osaka City, Osaka Prefecture Toa Boshoku Co., Ltd. (72) Kenji Shimokawa Tsurumi, Tsurumi-ku, Yokohama-shi, Kanagawa Chuo 2-12-1 Chiyoda Kakoh Construction Co., Ltd. (72) Inventor Masashi Saito Tsurumi-ku Tsurumi-ku, Yokohama-shi Kanagawa Chuo 2-chome 12-1 Chiyoda Kakoh Construction Co., Ltd.

Claims (2)

[Claims] 1. A web comprising a first polyolefin fiber having a high melting point of 50 to 100 denier and a second polyolefin fiber having a low melting point of 3 to 20 denier, and a base layer of ^{20 to} 100 g / m ² . And a non-woven fabric to be bonded by needle punching, the first fibers are bound by melting the second fibers, and the ratio of the first fibers is 30 to 7
A carrier for adhering microorganisms, which is made of a nonwoven fabric in which the proportion of the second fiber is 0% and 70 to 30%. 2. A method for producing a carrier for adhering microorganisms, which comprises the following steps (1) to (3): (1) 30 to 70% of first polyolefin fiber having a high melting point of 50 to 100 denier and second polyolefin fiber 70 having a low melting point of 3 to 20 denier 70 to
Forming a web with 30%. (2) A step of laminating the obtained web and a nonwoven fabric serving as a base layer of ²⁰ to 100 g / m ² and adhering them by needle punching. (3) A step of heating the obtained bonded nonwoven fabric at a temperature lower than the melting temperature of the first fibers and higher than the melting temperature of the second fibers to melt the second fibers and bind the first fibers.