WO1996026161A1

WO1996026161A1 - Catalytic filtering material for water purifier of catalytic oxidation type

Info

Publication number: WO1996026161A1
Application number: PCT/JP1995/001843
Authority: WO
Inventors: Akira Kojima; Norihiko Hirano
Original assignee: Akira Kojima; Norihiko Hirano
Priority date: 1995-02-20
Filing date: 1995-09-18
Publication date: 1996-08-29
Also published as: AU3485295A

Abstract

A catalytic filtering material for a water purifier of catalytic oxidation type, which is excellent in biocompatibility, inexpensive, durable and also excellent in purifying effect. The material comprises biomembrane carriers (10) each prepared by bundling a number of carbon fiber filaments (12) and forming the obtained bundle into such a configuration that each filament (12) is waving like algae in water.

Description

Description Contact oxidizing material in contact oxidation type water purification equipment

The present invention relates to a contact furnace material which is a biofilm carrier used in a method for purifying water from water and sewage, rivers, lakes and marshes using a biofilm (hereinafter referred to as a catalytic oxidation method). Background art

A contact oxidation method that removes BOD and COD-fine organic SS and turbidity components in wastewater by contacting wastewater with the biofilm composed of bacteria, protozoa and metazoans formed on the biofilm carrier. It has been known.

Figure 7 shows an example of a river water purification system using the catalytic oxidation method. The water of the river 1 is sent to the sand basin 3 after the suspended matter is removed by the screen 2, where pebbles and sand are removed, and then sent to the contact oxidation channel 4 by the bomb P. The contact oxidation water channel 4 has a structure in which a number of plastic corrugated plates 5 as biofilm carriers are stacked in parallel with a predetermined gap in a meandering water channel, and a contact material is disposed. When the water flows through the gap between the corrugated sheets 5, 5, the water comes into contact with the biofilm formed on the surface of the corrugated sheets 5 and is purified. The water purified by passing through the contact oxidation channel 4 is discharged to the river 1 from the drain channel 6.

However, as a biofilm carrier constituting the conventional contact base material described above, a synthetic resin that is lightweight and easy to process is widely used, but the synthetic resin has low biocompatibility and biocompatibility, and If these are left in large quantities, they can become industrial waste and cause pollution problems, Is not preferred. Conventional biofilm carriers are corrugated in order to increase the contact surface area, but the surface area of corrugated sheets (the area on which biofilms are formed) is inevitably limited.

Therefore, the inventor paid attention to carbon material, which is a hardly decomposable substance existing in nature. First of all, carbon materials are extremely excellent in biocompatibility and biocompatibility. Secondly, since carbon materials have a brass compress, it is considered to be a very easily established place for microorganisms with mainly negative loads. There are various types of carbon materials such as various graphite materials, glassy carbon materials, carbon black, activated carbon, charcoal, and coke. When using a carbon material, it should be formed into a shape suitable for the application. One of the carbon materials is carbon fiber. Carbon fiber is widely used in the aerospace and aviation industries, sports equipment, etc. because of its excellent specific strength, specific elastic modulus, and chemical resistance. Thirdly, carbon fibers can be formed by combining them with resin and concrete, and of course, carbon fibers alone can be formed into any shape because the carbon fibers themselves are interchangeable, and are durable. Also excellent in nature. Furthermore, when the degree of colonization of microorganisms (biofilm) on the biofilm carrier formed by carbon fiber was examined by experiments, very good results were obtained. Based on these results, the inventors proposed the present invention. That's what it is.

The present invention has been made based on the problems of the prior art and the consideration by the inventor described above, and its object is to have excellent biocompatibility and biocompatibility, to be inexpensive and durable, and to have a purifying action. An object of the present invention is to provide a contact oxidation material in a contact oxidation type water purification apparatus which is excellent in terms of quality. Disclosure of the invention

To achieve the above object, the contact oxidation material in the catalytic oxidation water purifying apparatus according to claim 1, wherein the biofilm carrier is made of carbon fiber. In this way, the carbon fiber constituting the biofilm carrier has high biocompatibility and biocompatibility, and does not go against the natural environment. In addition, carbon fibers are easily charged with a positive charge, and microorganisms that are easily charged with a negative load are easily attached. Therefore, the degree of biofilm fixation on carbon fibers is high.

According to claim 2, in the contact furnace material in the catalytic oxidation water purification apparatus according to claim 1, the biofilm carrier is formed by binding a large number of flexible and flexible carbon fiber filaments, by pressing a crucible, It is made up of a molded product that is formed into a predetermined shape that can be swung under water or delicate and oscillates under water. A flexible and interchangeable carbon arrowhead filament is bound or compressed. The molded body that has been formed into a predetermined shape by being knitted or retained can oscillate underwater like natural seagrass or algae, promoting the activity of the microorganisms that make up the biofilm. Supply essential oxygen.

According to a third aspect of the present invention, in the contact oxidation material in the catalytic oxidation water purifying apparatus a according to the second aspect, the molded body composed of carbon fiber filaments is formed into a strand having both ends bound, For example, braided strands, strands with tufts, strands with tricks, lanterns, brooms, Akita's flexible strands, filters, etc. Under the water, the carbon fiber filaments that make up the molded body oscillate, and the exposed surface area of the carbon male fiber filament is increased. The area on which the biofilm can settle) increases. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram of a biofilm carrier constituting a contact base material according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of various biofilm carriers constituting a contact substrate of the present invention. Fig. 3 shows carbon fiber strands, nylon strings and boletilles. Fig. 4 (a) is a graph showing the change in settled sludge amount between carbon fiber strand and boletylene tape, and (b) is the COD change between carbon arrowhead strand and polyethylene tape. Fig. 5 (c) is a graph showing the change in weight between carbon fiber strands and polyethylene tape, Fig. 5 (a) is a graph showing the change in the amount of settled sludge by carbon fiber strand type, and (b) is a graph showing the change over time. COD time-dependent characteristic diagram of carbon arrow fiber strand by form, (c) is a graph of weight change characteristic of carbon fiber strand by shape, and (a) of Fig. 6 is the change of settled sludge amount by type of carbon fiber strand. Characteristic diagram, (b) COD time-dependent characteristic diagram for each type of carbon fiber, (c) Weight change characteristic diagram for each type of carbon fiber, and Fig. 7 shows the overall configuration of a conventional water oxidation device using the catalytic oxidation method. It is a figure. BEST MODE FOR CARRYING OUT THE INVENTION SS

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a view showing a contact member according to a first embodiment of the present invention.

Reference numeral 10 denotes a carbon male fiber strand in which, for example, a large number (tens of thousands) of carbon male filaments 12 having a diameter of 7 m to 15 im are bundled and both ends are bound. Biofilm carrier. One end of the biofilm carrier 10 is connected and supported by a string-like connecting member 14 such as a rope supported by anchor bolts 13 fixed to the bottom of the contact oxidation water channel 4 as shown in FIG. 7, for example. The other end is connected to and supported by a pipe 17 connected to a float 15 via a string-like connecting member 16 such as a rope, thereby forming a contact layer material having a structure in which biofilm carriers 10 are arranged at predetermined intervals. Have been.

The biofilm carrier 10 is apparently a single bundle in the air due to the viscosity of the binder applied to the surface of each filament 12, but in the sea or water, the filament 1 2 is a spindle type separated from each other, the tide It can rock like seaweed in response to the movement of. For this reason, in water, the contact surface area of the biofilm carrier 10 (carbon fiber filament 12) with the microorganisms is increased, and the microorganisms are accordingly exposed to the biofilm carrier 10 (the carbon woven fabric constituting the biofilm carrier 10). It easily adheres to fiber filaments 1 2) and has a high rate of biofilm settlement and settlement.

As the biofilm carrier, various forms as shown in FIGS. 2 (a) to (g) are conceivable, in addition to the strand-shaped molded article having both ends bound as shown in FIG.

FIG. 2 (a) shows a braided strand formed body in which the carbon fiber filaments 12 are braided into a braid shape, and the filaments 12 are bulged at predetermined intervals in the longitudinal direction.

Fig. 2 (b) shows a tree-like strand formed by dividing the strand into several strands from the strand backbone 12a of the carbon fiber filament 12.

FIG. 2 (C) shows a broom-type strand formed by connecting and integrating a plurality of carbon woven strands 12 b with the strand base 12 a of the carbon fiber filament 12.

FIG. 2 (d) shows a lantern-shaped strand formed by forming a plurality of arc-shaped strands 12 c in the middle of the strand base 12 a of the carbon arrowhead filament 12.

Fig. 2 (e) shows an Akita straight strand-shaped molded product in which carbon fiber strands 12b are connected to and integrated with the strand base 12a of the carbon fiber filament 12 at predetermined intervals in the longitudinal direction. is there.

Fig. 2 (f) shows the arrangement of the cord-like connecting members 22 such as lobes at predetermined intervals, and twisting the carbon woven strands 12b to connect them so as to form a strand culling between the lobes. It is integrated. Reference numeral 24 indicates a connecting portion. Fig. 2 (g) shows a net-shaped strand formed by braiding carbon fiber strands 12b in a turtle-shape.

Other examples of the carbon arrowhead filament shaped body include a felt formed by compressing a strand into a felt, a strand wound into a coil, a twisted thread, a plain weave or a satin. Fiber-shaped molded articles woven in various forms such as weaving are conceivable.

As a biofilm carrier, a carbon male fiber filament 12 which is a component of the biofilm carrier can be separated in the sea or water, and a carbon arrowhead filament 12 which is a biofilm carrier can be used. The molded body is not limited to the above-mentioned molded body as long as the molded body has a large contact surface area with the microorganism.

Fig. 3 shows braided carbon fiber strands (hereinafter referred to as braids) and carbon fiber strands (Fig. 1), as shown in Fig. 1. Type strand), X-like carbon fiber (hereafter referred to as “filt”), nylon string and polyethylene tape are each suspended in an aquarium containing artificial sewage, and COD (chemical oxygen demand) in artificial sewage is suspended. 6 is a table showing the results of examining the change characteristics of the amount.

The braids, oscillating linear strands, flutes, nylon strings, and polyethylene tape, all of which were the same weight (18.9 g), oscillated in water as shown in Fig. 1. The upper and lower ends were fixed so that they could be used.

Artificial sewage in a clear water tank is prepared by dissolving reagents (dalcos, ammonium sulfate, dipotassium phosphate, sodium chloride, magnesium sulfate, chlorine chloride, etc.) in one liter of water and then discharging BOD 5 100 ppm of human sewage was prepared, and 10 times the volume of pond water was added to this artificial sewage, and water with a total volume of about 80 liters was used. Each of the above-mentioned test materials (braid, oscillating straight type strand, filter, nylon string and polyethylene tape) is suspended in a water tank, and while being aired, the test materials are finely irradiated for about one week in the sun. An experiment to establish the organism was performed. The change in COD in the artificial sewage was measured by potassium permanganate titration.

Figure 3 (a) shows the results of the first experiment (after 3 days), and Figure 3 (b) shows the results of the second experiment (after 1 day). According to the first experiment (Fig. 3 (a)), there is little difference in the COD value in any of the samples, but the second experiment (Fig. 3 (b)) For example, there is a large difference in COD value due to the difference in test materials. That is, the COD value is most remarkably reduced when a carbon male fiber material having a large surface area (felt) is used.

Fig. 4 shows the results obtained by aerating a PAN-based carbon male fiber strand (12 K oscillating linear strand) as a test material and a tape-shaped polyethylene as a comparative material in activated sludge. Fig. 4 (a) shows the amount of sludge when settled for 30 minutes after standing for 1 day. Fig. 4 (b) shows the change over time of COD, and Fig. 4 (c) shows the change of the weight of the sample.

The oscillating linear carbon arrowhead strand formed body is composed of five carbon strands (12K) bundled together (12Kx5 = 60K), and the upper and lower ends are bound and integrated, respectively. A molded body as shown in the figure was used. The length of the carbon fiber strand was 30 cm, and the total weight of the five carbon fiber strand compacts bundled was about 0.3 g. Five sets of the carbon fiber strand compact were prepared, and the weight was measured for each set.

Approximately 500 ml of activated sludge was added to each of the two 5-liter air collection bottles, and the total volume was reduced to approximately 3 liters with water. The contents of the air collection bottle were stirred well, allowed to settle naturally for 30 minutes, and the amount of sludge deposited was measured (the amount of settled sludge after 0 minutes). Next, five sets of carbon fiber strand molded bodies whose weights were measured were suspended in an air-collecting bottle containing activated sludge and aerated. BOD is 1 0 0 About 5% of the total volume of artificial sewage adjusted to 0 ppm was added as microbial nutrients. The liquid in the air-gathering bottle stirred by aeration was collected, the sludge was settled for 30 minutes, and then the COD of the supernatant was measured by the permanganate-powered rheometry. On the other hand, 5 sets of polyethylene tape (radiation 5 cm) adjusted to a weight in the range of 0.3 g to 0.4 g were subjected to the same treatment as above, and both were left for 1 day in the sun while aerated. .

After one day of release, the amount of sludge deposited by natural sedimentation for 30 minutes was measured. In addition, the supernatant was collected and the COD was measured. In addition, each sample was taken out, its weight was measured, and the increase in weight was defined as the biofilm fixation S, and the degree of biofilm fixation in each sample was examined.

In Fig. 4 (a), the amount of settled sludge is not changed at all in the case of polyethylene tape, while the amount of settled sludge is changed in the case of the oscillating straight di-type carbon woven fiber strand. It is extremely fading. This is due to the fixing biofilm carbon縑維, said carbon繳維strand, 84 9 cm ³ phases question sludge, i.e., the microorganism has been fixed. According to visual observation, a large spherical mass adheres to the carbon fiber strand molded body, whereas almost no adherence is observed to the polyethylene tape. From this, it can be said that the biofilm fixation to carbon moth is significantly higher than the biofilm fixation to polyethylene tape.

Fig. 4 (c) also shows the change in the total weight of the carbon arrowhead fiber strand compact including the deposits on the polyethylene arrowhead compact and the polyethylene tape, and there was a very large difference between the two. That is, in the case of the former, after one day, there was a weight increase of 9.20 g to 31.lg (average 16.32 g) (weight 增 due to attached matter). On the other hand, the weight of the latter (increase in weight due to extraneous matter) was 0.1 g or less.

Next, the effect of the shape of the carbon fiber strand molded body on the biofilm fixation degree is described. And conducted a similar experiment.

The carbon fiber strand compacts used in the experiment were the chochin type shown in Fig. 2 (d), the broom type shown in Fig. 2 (c), and the Akita Kanto type shown in Fig. 2 (e). A mold was used. A polyethylene tape was weighed the same as the carbon fiber strand molded body, and used as a comparative sample. Approximately 500 ml of activated sludge was added to each of the four 5-liter air collection bottles, and the total volume was adjusted to approximately 4 liters with water. The contents of each air collection bottle were stirred well, allowed to settle naturally for 30 minutes, and the amount of sludge deposited was measured (the amount of settled sludge after 0 minutes).

Each of the weight-measured samples is suspended in a separate air-collection bottle containing activated sludge, and oxygen is sent by aeration, and artificial sewage adjusted to a COD of 1000 ppm is used as microbial nutrients. About 5% of the total volume was added. The liquid in the air-gathering bottle that had been stirred with warm air was collected, and the sludge was settled for 30 minutes, and then the COD of the supernatant was measured by a permanganate-powered rheometry. Polyethylene tape was treated in the same manner as above, and both were aerated for 1 day in the sun.

Figure 5 (a) is shows the settling sludge volume, sedimentation sludge amount after 1 day, since in the case of using the carbon O維strand is 74 2 to 8 84 cm ^3, carbon O維strand the, so that the sludge 24 7 to 4 07 cm ³ is attached. On the other hand, in the case of polyethylene tape, the amount of attached sludge is only 8 cm ^3, which is about 130 to 1 Z50 in the case of carbon fiber strand. Regarding the effect of carbon fiber strand morphology on the amount of deposit, “Akita-no-Kato” had the largest effect (large amount of sludge attached).

Fig. 5 (b) shows the measurement results of COD. In any case, what is the COD value in one day? ~ 11 ppm, and no remarkable difference was found due to the difference in the type of the test material and the morphology of the carbon fiber strand. Fig. 5 (c) shows the sludge deposit attached to the carbon male fiber strand and polyethylene tape, and a marked difference was observed depending on the type and form of the test material. In other words, while carbon fiber strands increased by 22 to 38 g, polyethylene tape increased by only about 9 g. It was 2.7 to 4.2 times that of tape. Regarding the effect of the carbon fiber strand morphology on the amount deposited, the “broom type” was the largest. This result was consistent with the COD reduction in Fig. 5 (b). It is not inconsistent with the results of the settled sludge amount in Fig. 5 (a).

Next, the effect of the type of carbon fiber and the shape of the strand on biofilm settlement was examined.

The carbon fiber is a PAN-based carbon fiber strand (12K, Toray, T-300 with the applied sizing agent removed) and a pitch-based carbon fiber strand (twisted two fibers) ) Were used. If a sizing agent layer is formed on the surface of the carbon fiber, the rate of attachment of microorganisms to the carbon fiber is poor, so if the sizing agent is applied to the carbon fiber strand, remove the sizing agent in advance. It is necessary to keep it. In addition, the form of carbon moth fiber was “oscillating direct di type” shown in Fig. 1 and “broom type J” shown in Fig. 2 (c). In the former case, the length was 45 cm ( Five carbon moth strands weighing about 0.3 g) were bundled and used. In the latter “broom type”, five 12K strands 30 cm long were bundled and weighed about 1.6 g. And Fig. 6 (a) shows the change in the amount of settled sludge after one day. In the case of the PAN-based carbon arrowhead strand, the "oscillating straight type" is more stable than the "broom type". There are many. Fig. 6 (b) shows the change in the amount of COD. The PAN type is larger than the pitch type, and moreover, the "panning type j"

The "broom type" was larger. Fig. 6 (c) shows the change in weight of the carbon fiber strand after one day. The effect of the PAN system was larger than that of the pitch system (sludge adhesion amount, that is, the degree of biofilm fixation). In the case of the PAN system, there is a case where the weight increase is only 1.5 g, but this is the case where the test material is twisted and is out of the data. In addition, PAN-based carbon fiber has a larger amount of sludge attached (biofilm fixation degree) than pitch-based carbon fiber, but this is not a difference between the types of carbon fibers that are bitic or PAN-based. In contrast, PNA-based carbon arrowhead fibers are in the form of strands, whereas pitch-based carbon fibers are in the form of twisted yarns, and this twisted yarn shape reduces the contact surface area of carbon fibers and reduces the amount of attached sludge. This is probably the reason for this.

From the experimental results shown in FIGS. 3 to 6 above, carbon fiber adheres a larger amount of microorganisms in a short time than nylon polyethylene, that is, has a very high degree of biofilm settlement. It can be said that.

In addition, it can be said that the higher the surface area of the fiber weave filaments, the higher the degree of biofilm settlement.

In the above-described embodiment, only the PAN-based carbon fiber and the pitch-based carbon fiber were mentioned. However, the carbon fiber also includes phenol-based carbon fiber and cellulose-based carbon fiber. However, by forming them into a predetermined form, the present invention can be similarly applied to an activated carbon fiber having a large number of micropores formed on the surface. Further, the contact material in the first embodiment is merely an embodiment of the present invention, and the biofilm carrier 10 can be always kept at a constant water depth position by using a weight instead of the anchor bolt 13. It goes without saying that various structures can be considered depending on the specification of the arrangement of the biofilm carrier 10, such as a structure. Industrial applicability As is apparent from the above description, according to the contact material in the catalytic oxidation water purification apparatus according to claim 1, the biofilm carrier has high biocompatibility and biocompatibility and may become industrial waste. Since it is made of carbon fiber without carbon, it matches the natural environment.

In addition, since carbon fibers are easily charged with brass, they are easily charged with negative charges, and are very easily attached to microorganisms. Therefore, the degree of fixation of the biofilm to the biofilm carrier composed of carbon fibers is high. That is why the water purification effect is excellent.

In addition, since carbon fiber is inexpensive, it is possible to provide an inexpensive water purification apparatus having an excellent water purification action.

According to the second aspect, the molded body formed into a predetermined shape by bundling, compressing, knitting, or maintaining a flexible and flexible carbon fibrous filament is similar to natural seaweed or algae under water. Oscillation provides positive supply of oxygen to the microorganisms that make up the biofilm, promoting the degree of biofilm fixation and promoting the deterioration of water quality.

According to the third aspect of the present invention, under water, the carbon fiber filaments constituting the molded body oscillate, and the exposed surface area of the filament (interview on which the biofilm can settle) increases, so that the degree of fixation of the biofilm is increased. Water purification is improved.

Claims

The scope of the claims

1. A contact oxidation material in a contact oxidation type water purification device, wherein the biofilm carrier is composed of carbon fiber.

2. The biofilm carrier is formed by bundling, compressing, knitting or weaving a large number of flexible and flexible carbon fiber filaments into a predetermined shape that can swing underwater. The contact material in the catalytic oxidation water purifier according to claim 1, characterized in that the contact material is constituted by a molded body formed.

3. The molded body composed of the carbon arrowhead filaments has a strand shape, a net shape, a braided shape, a braided strand shape, a technical strand shape, a lantern type strand shape having both ends bound together. Claims characterized in that the carbon fiber filament is formed into a predetermined shape, such as a broom-shaped strand, an Akita canned strand, an X-fold, etc., in which the exposed surface area of the carbon fiber filament under water is large. 2. The contact material in the contact oxidation water purification device according to 2.