JP4839445B2 - Phosphorous collecting material, method for producing the same, and phosphorus collecting method - Google Patents

Description

  The present invention relates to a phosphorus collecting material for collecting phosphorus in water such as rivers, lakes, seawater and drainage. The present invention relates to a phosphorus collection material characterized by being recyclable and reusable and a method for producing the same.

  Phosphorus is an important material as a fertilizer and various industrial raw materials, and has been used and discharged in large quantities for many years. As a result, rivers and oceans are eutrophied and cause environmental problems such as the occurrence of large red tides and destruction of aquatic ecosystems. If left untreated, resources will be depleted in the near future. Definitely a real problem. Therefore, the recovery of phosphorus in wastewater has become an urgent issue, and research and development has been conducted in various fields, but it has not been put into practical use.

  These phosphorus removal technologies under development include a method (HS method or MAP method) that uses a microorganism to collect a relatively high concentration of phosphorus compounds contained in wastewater as phosphoric acid or organic phosphorus compounds. is there. In this method, the phosphorus compound in the wastewater is concentrated and collected in the sludge, but this sludge treatment becomes a new problem. On the other hand, a method for purifying rivers and lakes by collecting phosphorus compounds in rivers and lakes using phosphorus collectors has also been proposed. For example, phosphorus-absorbing substances such as aluminum hydroxide, iron hydroxide, and phosphate ore and zeolite are comprehensively immobilized in a water-soluble polymer gel to form a phosphorus collector, which can be used in rivers and lakes. By simultaneously removing low concentrations of phosphorus and ammonia (see Patent Document 1), and mixing calcium carbonate, which is a phosphorus-collecting component, with bentonite (clay mineral) and a water-soluble polymer compound, and then drying. There is a method for removing water at low concentrations in rivers and lakes (see Patent Document 2). Regarding the collection of low-concentration phosphorus, the purpose is to purify environmental water, and it has not been studied to collect and use phosphorus.

  On the other hand, as described above, phosphorus is an important material for various industrial raw materials, and is also an indispensable material for living organisms. Even though its importance is increasing year by year, Japan is 100% Rely on imports. However, it is estimated that phosphorus reserves in the world will be depleted in decades, and there are concerns about securing resources in Western countries, and the United States has already banned phosphorus exports.

Japanese Patent Laid-Open No. 7-8945 Japanese Patent Laid-Open No. 11-216479

  The above-mentioned methods for removing phosphorus and collecting phosphorus in drains, rivers and lakes are methods for wastewater treatment and purification of rivers and lakes from the viewpoint of environmental issues, not phosphorus collection methods from the viewpoint of resource problems. . Therefore, although purification of treated water can be expected, there is a problem that it is difficult to expect much in terms of recovery of phosphorus resources. That is, even though phosphorus is concentrated in the sludge produced from the wastewater treatment facility, it contains a large amount of metal components other than phosphorus and is inappropriate as a phosphorus resource as an industrial raw material. Therefore, the current situation is that it is incinerated or landfilled. On the other hand, according to Patent Documents 1 and 2, it is disclosed as a method for recovering and utilizing phosphorus that a phosphorus collection material containing a collected phosphorus compound is sprayed on a forest or a field as a fertilizer or a soil improvement material. Clearly, it is not suitable for recovery as an industrial raw material.

  The present invention has been made under such a background, and covers from relatively high concentration phosphorus-containing wastewater in factory wastewater and domestic wastewater to rivers, lakes, and low concentration phosphorus-containing water in seawater. In order to efficiently recover phosphorus in these forms in a reusable form, compounds that react selectively with phosphate group-containing compounds to form precipitates are highly dispersed and insolubilized in polymer compounds at the molecular level. To produce recyclable phosphorus scavengers. Next, the present invention provides a novel phosphorus collecting material that can easily collect the collected phosphorus with high purity, a method for producing the same, and a phosphorus collecting method.

The inventor of the present invention aims to make one or more of a zirconium compound (Zr compound) or a titanium compound (Ti compound) having a phosphorus scavenging function nanocomposite with a polymer compound by a cross-linking reaction so as to be insolubilized. Has succeeded in developing a new phosphorus collector. That is, the present invention dries an aqueous solution comprising at least one water-soluble Zr compound or water-soluble Ti compound and a water-soluble polymer compound having any one of a hydroxyl group, an amino group, and a carboxyl group at room temperature to 250 ° C. - heating, said water-soluble zirconium compound or a zirconium or titanium of the water-soluble titanium compound and said water-soluble polymer compound by direct cross-linking reaction was insolubilized by nanocomposite of those formed by the phosphorus adsorbent. Zr or Ti in the phosphorus collecting material is reacted with a phosphorus compound in water to form a phosphoric acid compound to collect phosphorus, and then it is easily regenerated to its original state by washing with alkali.

In the cross-linking reaction, a smectite swellable silicate mineral such as montmorillonite or hectorite or a synthetic smectite (smectite swellable layered silicate) is added and mixed, and the cross-linking reaction product is interposed between the layers. It is also possible to crosslink the silicate and further disperse the Ti compound or Zr compound. It is well known that water-soluble polymers such as polyvinyl alcohol (PVA) spread and intercalate between swellable silicate layers.

The water-soluble Zr compound or a water-soluble Ti compound, specifically, zirconyl chloride, zirconyl sulfate, zirconyl nitrate, zirconyl acetate, zirconyl ammonium carbonate, chelate zirconium, amino acid-based, zirconium sol hydroxide, zirconia sol It is preferably selected from one or more of water-soluble Zr compounds or Ti compounds selected from the group consisting of titanium trichloride, titanium tetrachloride, titanium sulfate, titanium oxychloride, titanium lactate, peroxotitanate, chelate titanate, and titania sol Furthermore, specific examples of water-soluble polymer compounds include polyvinyl alcohol, ethylene vinyl alcohol, polyacrylic acid, polyacrylamide, polyallylamine and carboxymethylcellulose, copolymers of these polymers and block polymers. A preferred embodiment is chosen from one or more water soluble polymer compound selected from the group consisting of mer. Furthermore, it is also possible to form a phosphorus scavenger using synthetic resin paper or nonwoven fabric formed from fibers of these water-soluble organic compounds. Incidentally, a polymer compound having a hydroxyl group, an amino group, or a carboxyl group reacts with a Zr compound or a Ti compound, and Zr or Ti crosslinks a side chain of the polymer to construct a three-dimensional structure that is hardly soluble in water. That is well known.

  Further, since this phosphorus collecting material can be regenerated by washing with alkali after collecting phosphorus, it can be used repeatedly, and the phosphate aqueous solution recovered at the time of regeneration is a phosphate containing almost no impurities. Since it is a solution, phosphorus can be easily concentrated and separated.

  According to the present invention, Zr or Ti easily binds to a phosphoric acid group compound, and liberates phosphoric acid easily by alkali washing to form and separate phosphates. It becomes possible to easily recover phosphorus by separating phosphate groups. As a result, an alkaline phosphate aqueous solution separated and recovered from the phosphorus collection material and concentrated to an extremely high concentration from the phosphorus concentration in the original drainage, rivers and lakes can be obtained. It becomes possible and can be reused as phosphorus resources.

The present invention is described in detail below. First, the phosphorus collecting material will be described. As the phosphorus collecting material, Patent Document 1 includes aluminum hydroxide, activated alumina, iron hydroxide, iron powder, Kanuma earth, allophane, bone charcoal, phosphorus ore, and magnesium. , Calcium carbonate is raised. Even if these have a function of collecting phosphorus in water, they cannot be used in the present invention. Three materials are required as a material having a phosphorus collecting function used in the present invention. That is, first a cross-linking reactivity with the polymer compound, a second water-soluble, it is renewability the third. The first function is an indispensable requirement for stably holding a phosphorus scavenging substance chemically bonded to a polymer compound. In physical holding simply by adsorption or the like, Will be released to cause a decrease in the performance of the phosphorus absorbent. The second function is a function necessary for producing a uniform phosphorus collecting material by mixing uniformly with a water-soluble polymer compound in the production of the phosphorus collecting material. The third function is the most important function of the present invention, and is a function necessary for collecting the collected phosphorus and reusing it as a phosphorus resource. Although some of the substances described in Patent Documents 1 and 2 have crosslinkability with a water-soluble polymer, they are all water-insoluble and do not have the second function. These phosphor oxides do not have the third function because they cannot be easily regenerated.

The first to satisfy the third function, this is material selected in consideration of economic efficiency, water-soluble Z r compound and a water-soluble T i compounds used in the present invention. As the phosphorus collecting material used in the present invention selected from such a viewpoint, zirconyl chloride, zirconyl sulfate, zirconyl nitrate, zirconyl acetate, zirconyl ammonium carbonate, chelate-based zirconium, aminocarboxylic acid-based zirconium, zirconium hydroxide sol, water-soluble Zr compounds such as zirconia sol, titanium trichloride, titanium tetrachloride, titanium sulfate, titanium oxy chloride, peroxo titanate, chelate titanates, water-soluble Ti compound such as titania sol and the like.

Next, the water-soluble polymer compound will be described. As the polymer compound used in the present invention, the following two functions are required. The first is a water-soluble, second is the cross-linking reactivity with Zr compound or Ti compound. The first function is a function required to produce a uniform phosphorus trapping material uniformly mixed and as described above a water-soluble Zr compound and Ti compound, second feature, phosphorus collecting function This is a function necessary for insolubilizing and stabilizing the Zr compound and Ti compound having bismuth. From such a viewpoint, the water-soluble polymer compound used in the present invention is a water-soluble polymer compound having a hydroxyl group, an amino group or a carboxyl group that causes a crosslinking reaction with Zr or Ti. Specifically, polyvinyl alcohol ( PVA), ethylene vinyl alcohol (EVOH), polyacrylic acid (PAA), polyacrylamide, polyallylamine and carboxymethylcellulose (CMC), copolymers of these polymers and block polymers. Among them, PVA is a preferable material in consideration of crosslinkability and economy.

Next , insolubilization by a crosslinking reaction will be described. When a Zr compound or Ti compound is added as a crosslinking agent to the water-soluble polymer compound and heat treatment is performed, Zr or Ti becomes a crosslinking point and reacts with the alcohol group, amino group or carboxylic acid group of the polymer chain to crosslink. Then, the polymer structure is three-dimensionalized and insolubilized. The insolubilization rate due to the cross-linking reaction varies depending on the ratio of the Zr compound or Ti compound and the water-soluble polymer material, the heating temperature and pH, and the combination of the compounds. That's fine. Generally, it can be insolubilized by drying and heating at room temperature, preferably 50 ° C to 250 ° C, but preferably a temperature range of 100 to 160 ° C is used.

In the present invention, in addition to the water-soluble Zr compound or water-soluble Ti compound and the water-soluble polymer compound, a smectite-based swellable layered silicate is added and mixed, and a phosphorus trap that causes a crosslinking reaction between these three substances. There is also gathering. The smectite-based swellable layered silicate used in the present invention is preferably a natural raw material such as montmorillonite or a clay mineral such as bentonite mainly composed of montmorillonite. These are natural silicate minerals belonging to smectite, but synthetic smectites such as saponite and hectorite can also be used. These three in the case of mixtures, the crosslinked product of the layered silicate -Zr / Ti- polymer compound polycation interlayer zirconium hydroxide and hydroxide of titanium of the smectite swellable layered silicate to penetrate Therefore, after dehydrating, it is heat-treated and solidified and used as a phosphorus scavenger.

In practice, it is necessary to form the phosphorus collecting material into an appropriate shape, but the shape can be freely selected depending on the application. For example, the product subjected to the crosslinking reaction can be used as a film or fiber. An appropriate carrier surface such as a ceramic honeycomb or a metal mesh can be coated and dried or heat-treated, or solidified and then pulverized to form pellets or honeycombs. Furthermore, the paper (synthetic resin sheet) which is molded using a fiber of the polymer compound and using a non-woven fabric, said water solution which or immersed in aqueous solution of the Zr compound and Ti compound, on the surface of the paper or non-woven fabric After applying or spraying, it is also possible to perform the above-mentioned heat treatment to cause a cross-linking reaction to insolubilize it and use it as a phosphorus scavenger.

  Next, examples of the present invention will be described. The present invention is not limited to these examples.

[Manufacture of phosphorus collector]
Zirconyl chloride (ZrOCl ₂ · 8H ₂ O) was used as the water-soluble Zr compound, and PVA (polymerization degree 1700, saponification degree 98%) was used as the water-soluble polymer compound. First, a homogeneous mixture is formed by mixing and stirring 160 ml of 10 wt% PVA aqueous solution with 40 ml of 0.5 mol / l zirconyl chloride aqueous solution, and the volume is reduced to about half in a hot water bath at 50 to 60 ° C. using an evaporator. Until concentrated. A 24-mesh stainless steel wire mesh is dipped in the viscous liquid obtained by this concentration three times to coat the viscous liquid in a film form on the surface of the metal mesh, and this is dried at 50 ° C. After washing with 0.05 mol / l NaOH aqueous solution to remove the chlorine remaining in the dried product, heat treatment is further performed at 150 ° C. for 1 hour to form a film-like phosphorus collector using a stainless steel wire mesh as a carrier. (Mesh film formation sample) was formed. The crosslinking reaction between Zr and PVA proceeds in any of the concentration step at 50 to 60 ° C., the drying step at 50 ° C., and the heat treatment step at 150 ° C.

[Collection of phosphorus using high-concentration phosphoric acid solution and regeneration of phosphorus collection material]
The phosphorus-collecting material produced in Example 1 was immersed in an aqueous solution of 0.1 mol / l phosphoric acid (H ₃ PO ₄ ) for 1 hour, washed thoroughly with water and adhered to remove the aqueous phosphoric acid solution. After that, the phosphoric acid collected by dipping in 0.05 mol / l NaOH aqueous solution was eluted from the phosphorus collection material, and the phosphorus collection material was regenerated. The amount of phosphorus collected was determined by ICP analysis of the phosphoric acid concentration of the NaOH aqueous solution. The regenerated phosphorus collection material was again immersed in the phosphoric acid aqueous solution for 1 hour, and the elution of the phosphoric acid collected in the above-described procedure, the regeneration of the phosphorus collection material, and the measurement of the amount of phosphorus collection were repeated. FIG. 1 shows the relationship between the number of repetitions and the amount of phosphorus collected. The phosphorus collection and elution mechanism is based on the fact that zirconium hydroxide in the phosphorus collection material reacts with phosphoric acid to produce a zirconium phosphate [Zr (HPO ₄ ) ₂ ] -like amorphous compound. By collecting the phosphoric acid in the phosphoric acid aqueous solution and immersing it in the NaOH aqueous solution, the phosphate group is eluted as sodium phosphate [Na ₃ PO ₄ or Na ₂ HPO ₄ ], and the Zr group is the original It is thought that it is regenerated to zirconium hydroxide.

  As is clear from FIG. 1, the initial amount of phosphoric acid collected is 1.6 milliequivalents (meq / g) or more per gram of the Zr-PVA composite dry film used for film formation. The collected amount of 1.3 meq / g was maintained even after repeated use. After that, it was confirmed that the collected amount of phosphorus was retained even after repeated use for 20 times, and was a phosphorus collecting material that was sufficiently practical.

[Collection of phosphorus using low-concentration phosphoric acid solution]
The phosphorus collection material manufactured in Example 1 was immersed in aqueous solutions having various phosphoric acid concentrations, and the amount of phosphoric acid collected was measured by the same method as in Example 2. The results are shown in Table 1.

  As is apparent from Table 1, it can be seen that phosphoric acid can be recovered from a phosphoric acid solution having a low concentration of 1 ppm. Moreover, although the same test was conducted using artificial seawater, there was almost no change in the amount collected even when repeatedly used, and the possibility of phosphorus recovery from seawater was also confirmed.

[Manufacture of phosphorus scavengers using smectite swellable silicate minerals ]
As a smectite-based swellable layered silicate, water and acetone (water: acetone = 2: 1) are added to and mixed uniformly with Na-type montmorillonite (ion exchange capacity CEC = 100 meq / 100 g), and 1 wt% of Na-type montmorillonite is dispersed. The liquid (Na-Mont dispersion) was prepared. A 10 wt.% PVA aqueous solution prepared separately was added to this dispersion in an amount of PVA / Mont = 0.5 by weight, and an excess of 0.1 mol / l zirconyl chloride aqueous solution was added and stirred. By mixing, montmorillonite, a cross-linked body of Zr and PVA (Mont-Zr-PVA) was synthesized between montmorillonite layers. The resulting suspension was washed with acetone and the solid content (Mont-Zr-PVA) was separated and recovered with a centrifuge, and the obtained solid content was insolubilized by heating at 120 ° C. for 1 hour. A phosphorus scavenger was produced.

[Collection and recycling of phosphorus by Mont-Zr-PVA]
A 0.1 mol / l orthophosphoric acid aqueous solution was prepared, and the powdered phosphorus-collecting material produced in Example 4 was added thereto and stirred for several hours to collect phosphorus, followed by centrifugation. After collecting the phosphorus collection material and thoroughly washing with water, 0.05 mol / l NaOH aqueous solution is added and stirred to regenerate the phosphorus collection material and elution into the solution of phosphoric acid (recovery of phosphoric acid) ) Tested. The amount of phosphoric acid eluted in the solution was measured by ICP to measure the amount of phosphorus collected. Moreover, the same test was repeated several times using the regenerated phosphorus collection material. The result is shown in FIG.

  As is apparent from FIG. 2, the phosphorus trapping material of the present invention has a substantially constant amount of phosphorus trapped, despite being regenerated six times, as indicated by the line (b) in FIG. Show. From this, it can be seen that the phosphorus collection material according to the present invention can be regenerated and used repeatedly. Incidentally, the data shown in the line (a) in the figure is the phosphorus collection by the Mont-Zr cross-linked product produced by synthesizing the cross-linked product of Mont-Zr without adding PVA in Example 4 by the same method. This is a test example using a material, and the first time shows a high phosphorus collection amount, but the second and third times and the phosphorus collection amount gradually decrease, indicating that recycling is impossible.

  The formation of a cross-linked body between the layers of the montmorillonite (Mont) and the collection of phosphoric acid will be described. Mont has a lattice constant a × b of 5.21 Å × 9.12 Å, and α-phosphate Zr has a lattice constant of 5.30 Å × 9.08 っ て, both having a layered structure. The lattice constant and atomic arrangement are very similar. Accordingly, it is possible to insert a phosphoric acid Zr layer between the layers of the Mont and alternately stack and combine them to crosslink. As shown in the X-ray diffraction pattern diagram of FIG. 3, the bottom spacing of Na-Mont is 12.5 mm (see (a) in the figure), but the bottom spacing is increased to about 22 mm by this zirconium hydroxide bridge. (See (b) in the figure). When orthophosphoric acid is added to this, the distance between the bottom surfaces becomes 19.4 mm (see (c) in the figure), and it can be seen that phosphoric acid is reacted with the Zr-Mont cross-linked product. The diffraction peak at d = 7.6Å is considered to be due to α-phosphate Zr produced outside the crystal of the crosslinked product. Moreover, since the interval between the bottom surfaces has returned to 12.6 mm by repetitive washing with water (see (d) in the figure), Zr between the layers is eluted together with Zr phosphate, and the Zr-Mont cross-linked product is washed with water. On the other hand, since it is unstable, it turns out that it is not suitable for a reproduction use. This coincides with the test result shown by the line (a) in FIG.

  On the other hand, in the case where PVA is added to Mont, as shown in the X-ray diffraction pattern diagram of FIG. In the case where a cross-linked product of Mont-Zr-PVA was formed by adding an aqueous solution of zirconyl chloride to this, the bottom surface spacing was almost unchanged at 24.9 mm (see (b) in the figure), but the crystallinity was improved. It was. Even if this Mont-Zr-PVA cross-linked product is repeatedly washed with water, there is almost no change in the distance between the bottom surfaces, and the fact that it can be recycled is consistent with the test results shown in the line (b) in FIG. Yes.

[Phosphorus collection and repeated regeneration test of collected material]
A phosphorus collecting material was produced in the same manner as in Example 1, and phosphorus collection from the phosphoric acid solution and a regeneration test of the phosphorus collecting material were repeated. In a 0.1 mol / l phosphoric acid (H ₃ PO ₄ ) aqueous solution, a phosphorus collection material (mesh film formation sample) produced by the same method as in Example 1 was immersed at room temperature for 2 hours. After removing the excess phosphoric acid aqueous solution attached and removing it, the phosphoric acid adsorbed by dipping in 0.05 mol / l NaOH aqueous solution is eluted from the collection material, and the amount of phosphorus eluted in the NaOH aqueous solution Was measured by ICP analysis. The phosphorus collecting material regenerated by releasing phosphorus was immersed again in the phosphoric acid aqueous solution for 2 hours, and the above operation was repeated, and 30 repetitive regeneration tests were performed. The result is shown in FIG. As is clear from the figure, Example 2 was well reproduced, and it was found that it had the ability to withstand repeated reproduction tests up to 30 times. In the repeated test, the phosphorus collection capacity (phosphorus adsorption amount) after the 20th time is 0.95 meq / g, which is substantially constant.

[Production and regeneration test of phosphorus collector using titanium compound]
14.3 g of titanium tetraisopropoxide (Ti (OC ₃ H ₇ ) ₄ ) was added to 240 ml of 1 mol / l hydrochloric acid solution (HCl / Ti = 5 in molar ratio) and stirred at room temperature for several hours. Titanium isopropoxide initially produced a gel-like white precipitate by hydrolysis. However, when stirring was continued, the solution was peptized with hydrochloric acid to obtain a transparent solution. A titanium isopropoxide hydrochloric acid solution was added to and mixed with an aqueous solution containing 5 wt% of PVA (polymerization degree 2000, saponification degree 98%). At this time, the mixing amount was adjusted so that the Ti / PVA weight ratio was 0.3 (30 wt%). The obtained mixed solution was formed into a film using a 24 mesh stainless steel wire mesh in the same manner as in Example 1, dried at 50 ° C., washed with 0.05 mol / l NaOH aqueous solution, and then dried at 100 ° C. using a dryer. Dry for 30 minutes followed by 1 hour at 120 ° C. Similarly, a sample in which the titanium content (Ti / PVA) was adjusted to 10 wt% was synthesized. Samples containing 30 and 10 wt% Ti are labeled Ti (30) -PVA and Ti (10) -PVA, respectively.

  A phosphoric acid collection test was performed on a Ti-PVA sample formed on a stainless steel mesh. In the test, a phosphoric acid solution having a phosphorus concentration of 300 ppm was used, and after immersion for 5 hours, the amount collected was measured from the change in concentration of the solution. Thereafter, the sample was washed thoroughly with water, the mesh sample was immersed in 0.05 mol / l NaOH aqueous solution for 3 hours, and the amount of desorption was measured from the amount of phosphoric acid eluted in the solution. IPC was used to measure the phosphoric acid concentration. Repeated tests are good, and phosphorus collection (adsorption) and desorption amount correspond well. FIG. 6 shows the measurement results of the amount of collected phosphorus determined from the amount of phosphorus desorbed in up to 5 repetition tests. This result shows that Ti-PVA can be repeatedly used for the adsorption and desorption of phosphorus, similarly to the Zr-containing sample. It was found that Ti (30) -PVA with a large Ti content has a phosphorus collection capacity (adsorption amount) three times or more larger than Ti (10) -PVA with a small content.

[Manufacture of phosphorus collecting material using PVA paper]
PVA paper made of PVA short fibers (commercially available PVA paper that has been partially formalized) is cut into approximately 3 cm squares, and this is cut into 0.05 mol / l ZrOCl _2. It was immersed in an 8H ₂ O aqueous solution, heated at about 80 ° C. for 1 hour, dried at 50 ° C., and washed with a 0.05 mol / l NaOH aqueous solution. Then, heat processing were performed at 120 degreeC for 1 hour, and the Zr-PVA composite was produced. In this synthesis, the PVA paper partially swells but does not dissolve and retains the paper shape. The Zr content was adjusted such that the Zr / PVA weight ratio was about 0.1 by adjusting the amount of ZrOCl ₂ .8H ₂ O immersion. The adsorption / desorption test of phosphoric acid was performed using the obtained Zr-PVA paper. Zr-PVA paper was immersed in a phosphoric acid aqueous solution containing 300 ppm of phosphorus for 12 hours for phosphorus adsorption, washed with water, and immersed in a 0.05 mol / l NaOH aqueous solution to desorb phosphorus. The amount of phosphorus absorbed and desorbed was measured using ICP and ion chromatograph.
The results are shown in FIG. By adsorption / desorption tests up to 5 times, the adsorption capacity is about 0.38 meq / g, which is lower than the mesh sample made by dissolving PVA, but has good repeatability, and PVA paper Even when used, it was found that a reusable phosphorus collecting material with good performance can be produced.

[Adsorption / desorption test of phosphorous acid]
Using a Zr-PVA mesh sample produced in the same manner as in Example 1, an adsorption / desorption test of phosphorous acid was performed. For comparison, an adsorption / desorption test of phosphoric acid was performed using the mesh sample prepared at the same time. The results are shown in FIG.
The phosphorus concentration of the solution is about 3,000 ppm for both phosphoric acid and phosphorous acid. As is apparent from FIG. 8, it was found that phosphoric acid and phosphorous acid showed similar adsorption / desorption capacity and could be used repeatedly.

[Phosphorus collection test from artificial seawater]
Using a Zr-PVA mesh sample produced by the same method as in Example 1, a phosphorus adsorption test in seawater was performed. Artificial seawater (3.4% salinity, breakdown of salinity: NaCl 77.9%, MgCl ₂ 9.6%, MgSO ₄ 6.1%, CaSO ₄ 4.0%, KCl 2.1%) was prepared and phosphoric acid Was diluted with artificial seawater to prepare artificial seawater containing phosphorus at a concentration of 10 to 3,000 ppm, and a phosphorus collection test was conducted. The results are shown in Table 2. As shown in Table 2, it was found that the amount of phosphorus trapped in seawater was hardly affected by the coexisting ions.

[Organic phosphorus collection test]
Using a Zr-PVA mesh sample produced by the same method as in Example 1, a collection test for organic phosphorus (phosphate ester) was performed. Table 3 shows the types of organic phosphorus, the concentration of phosphorus in the aqueous solution, the treatment time (immersion time), and the adsorption amount (collected amount). The phosphorus adsorption amount was measured by ICP. It has also been shown that it has an adsorption capacity for organophosphorus and is an effective collector for organophosphorus. As a result, it is understood that this is a promising phosphorus scavenger for surfactants, flame retardants, and biologically derived organic phosphorus.

  The above explanation is an example using zirconyl chloride and titanium tetraisopropoxide as the water-soluble Zr compound and water-soluble Ti compound, but the present invention is not limited to this, and as described above, other water-soluble A water-soluble Zr compound or a water-soluble Ti compound can be used. Similarly, a PVA test example is shown as a water-soluble polymer compound, but the present invention is not limited to this, and as described above, other water-soluble polymers that cause a crosslinking reaction with Zr or Ti. The use of compounds is also possible. In short, any combination of Zr or Ti having phosphorus collection ability and phosphorus detachment ability by alkali washing and a polymer compound that causes a crosslinking reaction may be used, and the combination is not particularly limited. .

  Moreover, since the phosphoric acid aqueous solution obtained by removing phosphoric acid by alkali washing is an alkaline phosphate aqueous solution containing almost no impurities, it can be easily recovered as a phosphorus compound in an industrially usable form. This makes it possible to easily establish a recycling system by collecting phosphorus resources that rely on 100% import. In this sense, the present invention can be said to be an extremely useful invention in terms of Japan's resource strategy.

  The present invention can produce a phosphorus scavenger at a low cost and easily using a water-soluble Zr compound or a water-soluble Ti compound and a water-soluble polymer compound as raw materials, and is not disposable as in the prior art. Since it is a recyclable phosphorus trapping material, the phosphate produced in the regeneration process can be used effectively as a new phosphorus resource, so it can recover phosphorus from wastewater, recover phosphorus from rivers and lakes, Furthermore, it can be used for phosphorus recovery from the ocean. Therefore, it is an invention that contributes to the solution of the phosphorus resource problem in Japan, as well as conventional environmental problems and ecosystem conservation problems, so its social impact is significant and is expected to be used in various fields. Is done.

It is a graph which shows one example of the relationship between the frequency | count of recycling of the Zr-PVA type | system | group phosphorus collection material which concerns on this invention, and phosphoric acid collection amount. It is a graph which shows one example of the relationship between the frequency | count of recycling of the montmorillonite-Zr-PVA type | system | group phosphorus collection material which concerns on this invention, and the montmorillonite-Zr type phosphorus collection material as a comparative example, and a phosphoric acid collection amount. It is a X-ray-diffraction pattern figure of a montmorillonite and a montmorillonite-Zr type crosslinked body. It is a X-ray-diffraction pattern figure of a montmorillonite-PVA system and a montmorillonite-Zr-PVA system. It is a graph of the other Example of the relationship between the frequency | count of recycling of the Zr-PVA type | system | group phosphorus collection material based on this invention, and phosphoric acid collection amount. It is a graph of the Example which shows one example of the relationship between the frequency | count of reproduction | regeneration of the Ti-PVA type | system | group phosphorus collection material which concerns on this invention, and phosphoric acid collection amount. It is a graph which shows one example of the relationship between the frequency | count of recycling of the phosphorus collection material using the PVA paper which concerns on this invention, and a phosphoric acid collection amount. It is a graph which shows one example of the relationship between the collection amount of phosphorous acid and phosphoric acid by the Zr-PVA type phosphorus collection material which concerns on this invention, and the frequency | count of recycling of a phosphorus collection material.

Claims (15)

A phosphorus collecting material for collecting phosphorus compounds in water,
An aqueous solution comprising one or more of a water-soluble zirconium compound or a water-soluble titanium compound and a water-soluble polymer compound having any one of a hydroxyl group, an amino group, and a carboxyl group is dried and heated from room temperature to 250 ° C. A recyclable phosphorus scavenger, characterized in that zirconium or titanium in a water-soluble zirconium compound or water-soluble titanium compound and the water-soluble polymer compound are insolubilized by direct crosslinking reaction.   One or more of the water-soluble zirconium compound or water-soluble titanium compound and the water-soluble polymer compound are interposed between smectite-based swellable layered silicates, and a kind of the water-soluble zirconium compound or water-soluble titanium compound. The recyclable phosphorus trapping material according to claim 1, wherein the water-soluble polymer compound and the smectite-based swellable layered silicate are insolubilized by a crosslinking reaction.   The recyclable phosphorus collector according to claim 2, wherein the smectite-based swellable layered silicate is a natural silicate mineral or synthetic smectite belonging to a smectite such as montmorillonite or hectorite.   The water-soluble zirconium compound or water-soluble titanium compound is zirconyl chloride, zirconyl sulfate, zirconyl nitrate, zirconyl acetate, zirconyl ammonium carbonate, chelate-based zirconium, aminocarboxylic acid-based zirconium, zirconium hydroxide sol, zirconia sol, titanium trichloride, 4. The water-soluble zirconium compound or titanium compound selected from the group consisting of titanium tetrachloride, titanium sulfate, titanium oxychloride, titanium lactate, peroxotitanate, chelate titanate, and titania sol. 5. Recyclable phosphorus collector as described in 1.   The water-soluble polymer compound is one of water-soluble polymer compounds selected from the group consisting of polyvinyl alcohol, ethylene vinyl alcohol, polyacrylic acid, polyacrylamide, polyallylamine and carboxymethylcellulose, copolymers of these polymers, and block polymers. The recyclable phosphorus collecting material according to any one of claims 1 to 4, which is a seed or more.   The recyclable phosphorus trap according to claim 5, wherein the water-soluble polymer compound is a polymer paper or a nonwoven fabric formed by using a fiber comprising at least one polymer compound according to claim 5. Gathering. A method for producing a recyclable phosphorus collector that collects phosphorus compounds in water,
An aqueous solution comprising one or more of a water-soluble zirconium compound or a water-soluble titanium compound and a water-soluble polymer compound having any one of a hydroxyl group, an amino group, and a carboxyl group is dried and heated from room temperature to 250 ° C. A method for producing a recyclable phosphorus scavenger, characterized in that zirconium or titanium in a water-soluble zirconium compound or water-soluble titanium compound and the water-soluble polymer compound are insolubilized by direct crosslinking reaction.   8. The smectite-based swellable layered silicate is added when insolubilizing one or more of the water-soluble zirconium compound or water-soluble titanium compound and a water-soluble polymer compound by a crosslinking reaction. A method for producing a recyclable phosphorus collector.   The method for producing a recyclable phosphorus scavenger according to claim 8, wherein the smectite-based swellable layered silicate is a natural silicate mineral or synthetic smectite belonging to a smectite such as montmorillonite or hectorite.   The water-soluble zirconium compound or water-soluble titanium compound is zirconyl chloride, zirconyl sulfate, zirconyl nitrate, zirconyl acetate, zirconyl ammonium carbonate, chelate-based zirconium, aminocarboxylic acid-based zirconium, zirconium hydroxide sol, zirconia sol, titanium trichloride, The water-soluble zirconium compound or titanium compound selected from the group consisting of titanium tetrachloride, titanium sulfate, titanium oxychloride, titanium lactate, peroxotitanate, chelate titanate, and titania sol. A method for producing a recyclable phosphorus collector as described in 1.   The water-soluble polymer compound is one of water-soluble polymer compounds selected from the group consisting of polyvinyl alcohol, ethylene vinyl alcohol, polyacrylic acid, polyacrylamide, polyallylamine and carboxymethylcellulose, copolymers of these polymers, and block polymers. It is a seed | species or more, The manufacturing method of the recyclable phosphorus trapping material in any one of Claims 7 thru | or 10. One or more water-soluble zirconium compounds or water-soluble titanium compounds according to claim 9 are dissolved in one or more solutions of the water-soluble polymer compound according to claim 11, which are dissolved at 100 ° C to 160 ° C. The method for producing a recyclable phosphorus collecting material according to claim 10 or 11, wherein a heat treatment is performed at 0 ° C to cause a direct crosslinking reaction to insolubilize.   The water-soluble polymer compound solution obtained by dissolving the water-soluble polymer compound in a solvent mainly composed of water and at least one of alcohols, glycols, acetone, and formamide is used. A method for producing a recyclable phosphorus collector as described in 1. Whether paper or nonwoven fabric formed from one or more fibers of the water-soluble polymer compound according to claim 11 is immersed in one or more aqueous solutions of the water-soluble zirconium compound or water-soluble titanium compound according to claim 10. Or after spraying or applying the aqueous solution of the water-soluble zirconium compound or titanium compound to the surface of the paper or nonwoven fabric of the water-soluble polymer compound, the paper or nonwoven fabric of the polymer compound is heated at 100 ° C. to 160 ° C. A method for producing a recyclable phosphorus trapping material, characterized in that a cross-linking reaction is directly caused to insolubilize. A phosphorus collection method for collecting phosphorus compounds in water,
The phosphorus collection material according to claim 1 is brought into contact with an aqueous solution containing a phosphate group compound to collect phosphorus by the phosphorus collection material, and then the phosphorus collection material. A phosphorus collecting method, wherein the phosphorus collected by removing the material by alkali cleaning is removed and regenerated and used repeatedly.

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