KR100284912B1 - High hygroscopic nonwoven fabric and method for manufacturing the same - Google Patents

Abstract

The present invention discloses a nonwoven fabric capable of efficiently removing sludge in wastewater and a method of manufacturing the same. When the sludge is compressed to remove the wastewater contained in the sludge, the wastewater is laminated on the first nonwoven member and the upper surface of the first nonwoven member, which serves as a filter that passes the wastewater but does not pass the sludge. Passing the wastewater that passed through the first nonwoven fabric, the structural reinforcing member for increasing the strength of the nonwoven fabric and laminated on the upper surface of the structural reinforcing member, the sludge is compressed to remove the wastewater contained in the sludge The wastewater treatment nonwoven fabric according to the present invention includes a second nonwoven fabric member which serves as a filter that passes the wastewater that passes through the structural reinforcing member but does not allow the sludge to pass through. In the process of dewatering a sludge, the sludge treatment rate, the water content of the sludge after dewatering, The sludge dewatering efficiency is superior when evaluating the residual amount of sludge contained in the wastewater after the collected sludge dewatering.

Description

High hygroscopic nonwoven fabric and method for manufacturing the same

The present invention relates to a nonwoven fabric for wastewater treatment and a method for manufacturing the same, and more particularly, to a nonwoven fabric and a method for producing the sludge in the wastewater.

Recently, due to environmental problems, attention has been focused around the world for wastewater treatment, and much research has been made on the development of more efficient wastewater treatment systems and wastewater treatment fabrics used therein. There are various types of sludge contained in the wastewater. For example, in the case of dyeing plant wastewater, coagulations such as dyes, mordants, various processing agents, and scavengers, in the case of paper mill wastewater, coagulation of pulp and various processing agents, and food residues in food factory wastewater, etc. Exists in the form of.

Wastewater treatment first begins with the process of removing sludge. However, in order to send the sludge removed from the wastewater to a waste treatment plant for disposal, it is preferable to reduce the amount of wastewater contained in the sludge, that is, the moisture content, as much as possible in terms of logistics cost or handling. As such, wastewater treatment systems used to remove wastewater from sludge are classified into two types, batch and continuous. The batch type is a method of removing wastewater remaining in the sludge by inserting a certain amount of sludge between two pieces of waste water treatment fabric and compressing it, which has the advantage of lowering the water content of the removed sludge, but has a low sludge treatment rate. On the other hand, the continuous type is a method to remove the wastewater contained in the sludge by supplying the sludge continuously while feeding the sludge between two sets of conveyor belts which are continuously attached to the wastewater treatment fabric and are continuously rotated. Sludge treatment speed is fast as ~ 15m / min, but the water content of the treated sludge is high, and there is a disadvantage in that it is necessary to repeat the treatment in order to remove the sludge.

On the other hand, as a fabric for wastewater treatment used in a wastewater treatment system, whether batch or continuous, a fine mesh-like woven fabric is conventionally used. This mesh woven fabric is woven using high-strength polyester monofilaments of about 2,000 to 3,000 denier, which is about the thickness of a fishing line. However, when the mesh type woven fabric is used for the process of compressing and removing wastewater from the sludge, the fabric does not discharge the wastewater effectively, so that the treated sludge has a high moisture content, and small sludge is filtered out through the mesh with the wastewater. There is a problem that passes through as it is.

Therefore, even if the sludge is dewatered using the conventional wastewater treatment mesh woven fabric, the water content of the treated sludge is high, so that the logistics cost for transporting the sludge is not only increased, but excessive sludge is added to the wastewater removed from the sludge. Since it is included, there is a problem that the sludge removal process must be further passed before the wastewater is discharged.

Therefore, the technical problem to be achieved by the present invention is to improve the dewatering of the wastewater from the sludge in order to solve the above problems and to improve the wastewater of the improved form that can reduce the amount of residual sludge contained in the wastewater removed from the sludge It is to provide a nonwoven fabric for treatment.

Another technical problem to be achieved by the present invention is to provide a method for producing such a nonwoven fabric.

1 schematically shows a wastewater treatment system used to remove moisture from sludge.

<Explanation of symbols for main parts of the drawings>

1: sludge distribution port 3: upper belt

5: lower belt 7: first compression cylinder

9: second compression cylinder 11: series of cylinders

13: hydraulic cylinder

In order to achieve the above technical problem, the present invention provides a nonwoven fabric for wastewater treatment, wherein the nonwoven fabric is a filter that passes through the wastewater but does not pass the sludge when the sludge is removed to remove the wastewater contained in the sludge. A first nonwoven member acting; A structural reinforcing member laminated on an upper surface of the first nonwoven member and configured to pass wastewater that has passed through the first nonwoven fabric and to increase strength of the nonwoven fabric; And laminated on the upper surface of the structural reinforcing member, and when the sludge is removed to remove the wastewater contained in the sludge, the structural reinforcing member serves as a filter that passes the wastewater but does not pass the sludge. It provides a nonwoven fabric for wastewater treatment, comprising a nonwoven fabric member.

In the nonwoven fabric for wastewater treatment according to the present invention, the first and second nonwoven members are made of melamine-formaldehyde resin, urea-formaldehyde resin, phenol-formaldehyde resin, melamine-phenol-formaldehyde resin, and aniline-formaldehyde. The surface may be applied by one or more resins selected from the group consisting of resins.

In order to achieve the above another technical problem, the present invention comprises the steps of: (a) carding a collection of short fibers to form the first and second nonwoven members in the form of a web (web); (b) laminating and preneedling in order in the order of the first nonwoven member, the structural reinforcing member, and the second nonwoven member by inserting a structural reinforcing member between the first and second nonwoven members. step; And (c) needling the laminate to adhere the first and second nonwoven members and the structural reinforcement member to each other and to compact the structure of the first and second nonwoven members and the structural reinforcement member. It provides a method for producing a nonwoven fabric for wastewater treatment, comprising the step of.

In the nonwoven fabric for wastewater treatment according to the present invention, after the step (c), the surfaces of the first and the second nonwoven members are made of melamine-formaldehyde resin, urea-formaldehyde resin, phenol-formaldehyde resin, melamine-phenol-form The method may further include applying to any one or more resins selected from the group consisting of aldehyde resins, and aniline-formaldehyde resins.

In the nonwoven fabric for wastewater treatment and a method for manufacturing the same according to the present invention, the structural reinforcing member is preferably a woven fabric in a mesh shape at intervals of 1 to 5 mm.

In the wastewater treatment nonwoven fabric according to the present invention and a method of manufacturing the same, the structural reinforcing member is selected from the group consisting of polyethylene terephthalate filament yarn, nylon 6 filament yarn, nylon 66 filament yarn, polypropylene filament yarn, and wool staple yarn It is preferable that it is a woven fabric which consists of filament yarn or staple yarn which has the fineness of 2,000-3,000 denier above.

In the wastewater treatment nonwoven fabric according to the present invention and a method of manufacturing the same, the first and second nonwoven fabrics are composed of polyethylene terephthalate short fibers, nylon 6 short fibers, nylon 66 short fibers, polypropylene short fibers, and wool short fibers. At least one short fiber selected from the group is preferably composed of short fibers having a fineness of 5 to 20 denier and a length of 3 to 4 inches.

Next, the method for producing a nonwoven fabric for wastewater treatment according to the present invention will be described in more detail.

First, the aggregate of short fibers is carded to produce a web. The short fibers are composed of polyethylene terephthalate short fibers, nylon 6 short fibers, nylon 66 short fibers, polypropylene short fibers, or wool, and among them, the wool short fibers are the most preferred among them to effectively remove moisture from the sludge. Do. On the other hand, it is preferable to have the fineness of 5-20 denier of the said short fiber. If the fineness is less than 5 denier, there is a problem that the pores become smaller and the restoring force is lowered, and if the fineness exceeds 20 denier, the pores become too large and there is a problem that the sludge is not filtered much.

Subsequently, the structural reinforcement member is sandwiched between the two nonwoven fabrics, and preneeled at a low speed so that the nonwoven fabric and the structural reinforcement member are coupled to each other. In the pre-needling process, a needle of a needling machine penetrates the nonwoven fabric and the structural reinforcing member to entangle the short fibers of the nonwoven fabric with each other, thereby joining the two nonwoven fabrics and the structural reinforcing members stacked therebetween. . Here, the case where one structural reinforcing member is laminated between two nonwoven fabrics has been described. However, when one structural reinforcing member is laminated between four nonwoven fabrics of two upper and lower sheets, or two structural reinforcing materials are arranged between three nonwoven fabrics. The combination is not particularly limited as long as the upper and lower surfaces of the nonwoven fabric for wastewater treatment are composed of nonwoven fabrics, such as when two members are laminated.

The structural reinforcing member is a woven fabric in a mesh shape at intervals of 1 to 5 mm, and serves to extend the service life of the nonwoven fabric for wastewater treatment according to the present invention. In addition, if the mesh spacing is less than 1mm, there is a problem that the amount of dehydration from the sludge is small, if it exceeds 5mm there is a problem in filtering the fine sludge.

The structural reinforcing member is a woven fabric using polyethylene terephthalate filament yarn, nylon 6 filament yarn, nylon 66 filament yarn, polypropylene filament yarn, or wool staple yarn having a fineness of 2,000 to 3,000 denier. If the fineness of the filament yarn constituting the structural reinforcing member is less than 2,000 denier, there is a problem that the tensile property is lowered, and if it exceeds 3,000 denier, there is a problem in dewatering the sludge.

Subsequently, by further needling the resultant at high speed, the short fibers of the nonwoven fabric are more entangled with each other, thereby firmly bonding the nonwoven fabric and the structural reinforcing member to each other and making the structure of the nonwoven fabric and the structural reinforcing member compact. Overall, the volume of the nonwoven fabric for wastewater treatment according to the present invention is reduced. This completes the wastewater treatment nonwoven fabric according to the invention in the form of a felt fabric. However, in order to remove the fine sludge stuck to the nonwoven fabric after the wastewater treatment, the surface of the nonwoven fabric may be melamine-formaldehyde resin, urea-formaldehyde resin, phenol-formaldehyde resin, melamine-phenol-formaldehyde resin, or aniline-formaldehyde resin. It is preferable to apply | coat with a etc. However, in this case, if the coating amount of the resin is excessive, there is a problem that the waste water does not pass because the pores of the nonwoven fabric is blocked, so the coating amount of the resin should be adjusted so as not to be excessive. The density of the wastewater treatment nonwoven fabric thus prepared is typically 2,000-2,500 g / m ² when the thickness of the nonwoven fabric is 6 mm.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the following Examples.

First, the operation mechanism of the wastewater treatment system used to test the performance of the wastewater treatment nonwoven fabric will be described with reference to FIG.

1 schematically shows a wastewater treatment system used to remove moisture from sludge.

Referring to Figure 1, the sludge is continuously introduced into the wastewater treatment system through the sludge distribution port (1). After the sludge is placed on the upper belt 3, the sludge is conveyed along the upper belt 3 in the direction of the arrow, and after being stacked with the lower belt 5, the sludge is introduced into the first compression cylinder 7. The sludge is compressed while passing through the first compression cylinder 7 and the second compression cylinder 9 and a series of cylinders 11 therebetween to remove the waste water contained therein. At this time, the surface of the upper belt (3) and the lower belt (5) is covered with a non-woven fabric for wastewater treatment or a conventional mesh type woven fabric according to the present invention to be tested. Therefore, the wastewater treatment fabric mounted on the upper belt and the lower belt should preferably have the property of passing the wastewater well but of the sludge. At this time, the pressure applied to the sludge is adjusted by increasing or decreasing the pressure of the hydraulic cylinder 13 to increase or decrease the tension applied to the lower belt.

Meanwhile, the wastewater removed between the first and second compression cylinders 7 and 9 and in other parts is collected and discharged together. In addition, the sludge that has passed through the second compression cylinder is recovered and disposed of, and the sludge at this time is in a state suitable for transporting to a waste disposal plant in the state where a large part of the wastewater contained therein is removed.

In the wastewater treatment system, the upper and lower belts 3 and 5 continuously repeat the operation of pressing and removing wastewater from the sludge while moving in the direction of the arrow.

Next, in the Example and the comparative example of this invention, the performance evaluation method about the nonwoven fabric for wastewater treatment is demonstrated.

(1) moisture content

Dyeing plant wastewater, leather factory wastewater, paper mill wastewater, while changing the wastewater treatment fabric mounted on the upper belt and the lower belt of the wastewater treatment machine (manufactured by Bow Co., Ltd.) of FIG. 1 into a nonwoven fabric manufactured according to the following example. After dewatering the sludge collected from domestic wastewater, the water content of the sludge was measured according to the oven method described in KS K0220 as follows.

In other words, after taking five sludge 500g test pieces after dehydration treatment, and put them in the oven adjusted to 105 ~ 110 ℃ to compare the weight change of sludge after 24 hours. Next, the moisture content was calculated for the five test pieces according to the following equation, and the values thereof were averaged and shown in Table 1.

Moisture Content = [(O-D) / D] × 100

O: weight of initial test piece

D: Weight of test piece after drying for 24 hours

(2) sludge treatment speed

The sludge treatment rate is a measure of the amount of dyeing wastewater introduced per unit time, and the unit is calculated in ton / hour or ℓ / min. Alternatively, the sludge treatment rate can be simply measured as the revolution speed of the compression roller. In this case, the following equation is used.

revolution / min × πD

Here, D represents the diameter of the compression roller.

(3) Residual sludge contained in wastewater dewatered from wastewater treatment system

The amount of residual sludge contained in the wastewater collected and collected together at the bottom of the wastewater treatment device of FIG. 1 for the production of the test piece for measuring the moisture content of (1) was measured as follows.

That is, five specimens of 1 L were collected from the collected wastewater and then filtered using a funnel and a suction flask. The remaining sludge remaining on the filter paper was collected and placed in an oven controlled at 105 to 110 ° C., and after 24 hours, the weight of the remaining sludge was measured for the five test pieces. Next, the value was averaged and shown in Table 2.

Example 1

An aggregate of 18 denier polyethylene terephthalate short fibers was put in a 72-inch N 700 carding machine of Daewon Machinery, and carded to produce a nonwoven fabric having a thickness of 0.4 cm. Subsequently, between the two nonwoven fabrics, 1,500 denier PET multifilament yarns were used to insert a woven fabric to form a mesh of 3 mm intervals, and then preneeled with an F 400 pre-needling machine manufactured by a weaving machine. Join the fibers to some extent. Subsequently, a combination of nonwoven / net-shaped woven / nonwoven fabrics loosely attached to each other by pre-needling by needleing at a speed of 500 strokes / minute using 3500 needles / 0.35m ² needle board in Dilo's OR35 needling machine Were strongly attached to each other and the structure of the nonwoven fabric / mesh eye cloth / nonwoven fabric was made compact. Subsequently, a coating liquid prepared by dissolving 200 g of melamine-formaldehyde resin (THM-80, manufactured by Taehwa Industry Co., Ltd.) in 800 g of water was applied to the upper and lower surfaces of the nonwoven fabric so that the coating density of the resin was 50 to 200 g / m ² , and dried. To prepare a non-woven fabric for wastewater treatment 6mm thick.

Example 2

A nonwoven fabric for wastewater treatment was prepared in the same manner as in Example 1 except that 5 denier wool short fibers were used.

Example 3

A nonwoven fabric for wastewater treatment was prepared in the same manner as in Example 1 except that 10 denier polypropylene short fibers were used.

Example 4

A nonwoven fabric for wastewater treatment was prepared in the same manner as in Example 1 except that 20 denier nylon 6 short fibers were used.

Comparative example

Comparative tests were carried out using a conventional SCANDIA FELT AB, a Swedish company HoGSJO GUSUM, as a conventional mesh woven fabric. The mesh-shaped woven fabric is a woven fabric consisting of a warp yarn of about 434 deniers (inclined density of 33 pieces / cm) and a weft yarn of about 7130 deniers (weft density of 8 / cm).

Dyeing Plant Wastewater (%) Leather Factory Wastewater (%) Paper Mill Wastewater (%) Domestic wastewater (%) Example 1 74.2 60.1 68.6 70.3 Example 2 73.0 59.2 67.0 68.8 Example 3 76.1 61.9 69.5 71.1 Example 4 73.8 60.3 67.9 70.1 Comparative example 87.0 68.5 79.3 82.9

Referring to Table 1, the moisture content of the sludge dewatered using the nonwoven fabric for wastewater treatment of Examples 1 to 4 in all kinds of wastewater was the water content of the sludge dehydrated using the conventional mesh woven fabric according to the comparative example. It can be seen that the reduction is about 10 percentage points. Therefore, it can be seen that when the nonwoven fabric for wastewater treatment of Examples 1 to 4 is used, the sludge can be separated from the wastewater more efficiently than in the case of using the conventional mesh type woven fabric of the comparative example.

Processing speed (m / min) Residual sludge amount (g / ℓ) Example 1 13.5 4.7 Example 4 13.5 4.3 Comparative example 12.8 25.1

Referring to Table 2, the treatment speed of the process of dewatering sludge using the wastewater treatment nonwoven fabrics of Examples 1 and 4 was 13.5 m / min, which was 12.8 m / min when using a conventional mesh-shaped woven fabric. It turns out that it rose slightly more. On the other hand, after dewatering the sludge and looking at the amount of remaining sludge contained in the waste water collected by collecting together from the bottom of the wastewater treatment machine, 4.7g / ℓ and 4.3g / when using the nonwoven fabric for wastewater treatment of Examples 1 and 4 It can be seen that, as ℓ, it was drastically lowered than 25.1 g / L when the conventional mesh woven fabric of the comparative example was used. Therefore, it is understood that the use of the wastewater treatment nonwoven fabrics of Examples 1 and 4 can effectively prevent the remaining sludge from escaping into the wastewater when compressing the sludge placed between the upper belt and the lower belt for dewatering the sludge. Can be.

As described above, the nonwoven fabric for wastewater treatment according to the present invention includes the sludge treatment rate, the water content of the sludge after dewatering, and the residual water contained in the wastewater collected after sludge dewatering in the process of dewatering sludge collected from various factory wastewater. When evaluating the amount of sludge, sludge dewatering efficiency is excellent.

Claims (10)

In the nonwoven fabric for wastewater treatment, the nonwoven fabric is A first nonwoven member serving as a filter which passes the waste water but does not pass the waste water when the sludge is compressed to remove the waste water contained in the sludge; A structural reinforcing member laminated on an upper surface of the first nonwoven member and configured to pass wastewater that has passed through the first nonwoven fabric and to increase strength of the nonwoven fabric; And Stacked on the upper surface of the structural reinforcing member, when the sludge is removed to remove the waste water contained in the sludge, the waste water passing through the structural reinforcing member passes through the role of the filter does not pass the sludge A nonwoven fabric for wastewater treatment comprising a second nonwoven fabric member. The method of claim 1, wherein the first and second nonwoven members are from a group consisting of melamine-formaldehyde resin, urea-formaldehyde resin, phenol-formaldehyde resin melamine-phenol-formaldehyde resin, and aniline-formaldehyde resin. A nonwoven fabric for wastewater treatment, wherein the surface is coated with at least one selected resin. The nonwoven fabric for treating wastewater according to claim 1, wherein the structural reinforcing member is a woven fabric which is woven in a mesh shape at intervals of 1 to 5 mm. The method of claim 1, wherein the structural reinforcing member is at least one selected from the group consisting of polyethylene terephthalate filament yarn, nylon 6 filament yarn, nylon 66 filament yarn, polypropylene filament yarn, and wool staple yarn, the fineness of 2,000 ~ 3,000 denier A nonwoven fabric for wastewater treatment, characterized in that it is a woven fabric made of filament yarn or staple yarn. The method of claim 1, wherein the first and the second nonwoven fabric is one or more short fibers selected from the group consisting of polyethylene terephthalate short fibers, nylon 6 short fibers, nylon 66 short fibers, polypropylene short fibers, and wool short fibers. Nonwoven fabric for wastewater treatment, characterized in that the nonwoven fabric consisting of short fibers having a fineness of ~ 20 denier. (a) carding a collection of short fibers to form first and second nonwoven members in the form of a web; (b) laminating and preneedling in order in the order of the first nonwoven member, the structural reinforcing member, and the second nonwoven member by inserting a structural reinforcing member between the first and second nonwoven members. step; And (c) needling the laminate to attach the first and second nonwoven members and the structural reinforcement member to each other and to compact the structure of the first and second nonwoven members and the structural reinforcement member. Method for producing a nonwoven fabric for wastewater treatment, comprising a. The method of claim 6, wherein after the step (c), the surfaces of the first and second nonwoven members are separated into melamine-formaldehyde resin, urea-formaldehyde resin, phenol-formaldehyde resin, melamine-phenol-formaldehyde resin, and aniline. -A method of producing a nonwoven fabric for wastewater treatment, further comprising the step of applying with at least one resin selected from the group consisting of formaldehyde resins. The method of claim 6, wherein the structural reinforcing member is a woven fabric woven in a mesh shape at intervals of 1 to 5 mm. The method of claim 6, wherein the structural reinforcing member is at least one selected from the group consisting of polyethylene terephthalate filament yarn, nylon 6 filament yarn, nylon 66 filament yarn, polypropylene filament yarn, and wool staple yarn, the fineness of 2,000 ~ 3,000 denier A nonwoven fabric for wastewater treatment, characterized in that it is a woven fabric made of filament yarn or staple yarn. The method of claim 6, wherein the first and the second nonwoven fabric is one or more short fibers selected from the group consisting of polyethylene terephthalate short fibers, nylon 6 short fibers, nylon 66 short fibers, polypropylene short fibers, and wool short fibers. Method for producing a non-woven fabric for wastewater treatment, characterized in that the nonwoven fabric consisting of short fibers having a fineness of ~ 20 denier.