JP2011167689A - Solid phosphorus removing agent and waste-water purifying tank equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid phosphorus removing agent wherein the agent is agglomerated from an iron salt or an aluminum salt (both are very water-soluble) which reacts with a phosphate ion to solidify the phosphate ion, and also controlled-releasability (low in water dissolvability) is given to the agglomerated material, and to provide a production method of the solid phosphorus removing agent, a dissolving method of the solid phosphorus removing agent in water, a dissolving apparatus for the solid phosphorus removing agent and a waste-water purifying tank equipped with the dissolving apparatus. <P>SOLUTION: The solid phosphorus removing agent contains the iron salt or the aluminum salt, a binder, and a vegetable oil as a liquid hydrophobic material. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention treats combined wastewater (hereinafter simply referred to as wastewater) such as human wastewater, domestic wastewater, and organic wastewater discharged from small-scale building facilities such as detached houses, apartment houses, and convenience stores. In particular, the present invention relates to a solid phosphorus removing agent formed by molding iron salt or aluminum salt into a lump such as a tablet, and a drainage septic tank provided with the same, which is used in a septic tank that also removes phosphorus.

Wastewater discharged from the above facilities is treated by a wastewater septic tank mainly composed of anaerobic and aerobic biological treatment functions, disinfected, and then discharged. These wastewater septic tanks remove solids and organic matter in the wastewater to reduce (remove) the BOD of the pollution index, and circulate aerobic treated water in the anaerobic and aerobic treatment systems to generate nitrogen. Remove minutes.
However, even if such a treatment is performed, the phosphorus content (phosphate ions) cannot be removed and is released as it is. Therefore, in the drainage septic tank, for the purpose of removing phosphate ions, polyvalent metal ions such as iron, aluminum and calcium are supplied into the wastewater, and the solids are reacted by reacting the polyvalent metal ions with phosphate ions. A reaction agglomeration method is used in which the particles are formed (or formed into particles) and removed by a treatment such as precipitation, flotation or filtration.

And as a method of supplying this polyvalent metal ion into wastewater, for example, a polyvalent metal salt that reacts with phosphate ions and a chlorine-based compound having a disinfecting ability are mixed to form a tablet, and this tablet is subjected to purification treatment. There exists a phosphorus removal disinfection solid agent which makes it contact with the process water which ended, and removes phosphate ion and disinfects the process water (refer to patent documents 1).
Furthermore, since polyvalent metal salts are highly soluble in water, heat them by mixing organic compounds such as higher fatty acids, higher alcohols and paraffins with iron salts, aluminum salts, etc. in order to give them sustained release properties. There are solid denitrification and dephosphorization accelerators that are dissolved and cooled and solidified, and this lump is added to an activated sludge type aeration tank and dissolved (see Patent Document 2).

JP 2000-210676 A JP 2001-269689 A

In an example such as a phosphorus removal sterilizing solid agent, since it contains a sterilizing agent, it needs to be contacted with treated water after the biological treatment is completed, and in an example such as a solid denitrification / dephosphorization accelerator, Since the polyvalent metal salt is solidified with an organic compound that is insoluble in water, it is presumed that polyvalent metal ions corresponding to the reaction amount cannot be eluted, and the required amount is excessive or insufficient.
The present invention solves the above-mentioned problems, agglomerates an iron salt or aluminum salt (both having high water solubility) that reacts with phosphate ions to solidify the phosphate ions, and gradually releases the aggregates. It aims at providing a solid phosphorus removal agent which has the property (water slow solubility), and a waste water septic tank provided with the same.

While the inventors are proceeding with studies aimed at solving the above-mentioned problems, a natural substance-derived polymer substance or a water-soluble polymer substance is added to an iron salt or an aluminum salt for the purpose of binding and pulverized. After mixing, kneading and adding vegetable oil to this, it was found that when it was further hardened like a tablet, it itself was hardly soluble in water and exhibited sustained release properties. The present invention has been found based on these examination results and the like.
The present invention has the following configuration in order to solve the above problems.
(1) The present invention relates to a solid phosphorus removing agent comprising an iron salt or aluminum salt, a binder, and vegetable oil as a liquid hydrophobic substance.
(2) The present invention is characterized in that the vegetable oil described in item (1) is an essential oil.
(3) The present invention is characterized in that the essential oil according to item (2) is pine oil.
(4) In the item (1), the present invention is characterized in that the binder is a polymer substance or derivative substance derived from a natural product, or a water-soluble synthetic polymer substance.
(5) This invention relates to the waste water septic tank provided with the solid phosphorus removal agent in any one of term (1), (2), (3) or (4).

Since the solid phosphorus removing agent of the present invention contains vegetable oil as a liquid hydrophobic substance in addition to the iron salt or aluminum salt and the binder, the sustained release property to water can be further enhanced.
Moreover, since the waste water purification tank of this invention is equipped with said solid phosphorus removal agent, since it can also remove phosphorus other than BOD and nitrogen, highly treated water can be obtained.

The process drawing of an example which shows the manufacturing method of the solid phosphorus removal agent which consists of the iron salt or aluminum salt of this invention, binder, and a liquid hydrophobic substance. It is an example of a solid phosphorus removal agent melt | dissolution apparatus, (a) is a schematic plan view, (b) is AA sectional drawing of (a). It is an example which shows another solid phosphorus removal agent melt | dissolution apparatus, and the sectional drawing. It is an example which shows another solid phosphorus removal agent melt | dissolution apparatus, (a) is a schematic plan view in case a solid phosphorus removal agent is continuously immersed in water, (b) is BB sectional drawing of (a). It is an example which shows another solid phosphorus removal agent melt | dissolution apparatus, (a) is a schematic sectional drawing when a solid phosphorus removal agent is intermittently immersed in water, (b) is the outline when a solid phosphorus removal agent is exposed. Sectional drawing. BRIEF DESCRIPTION OF THE DRAWINGS It is an example which shows the waste water septic tank provided with the solid phosphorus removal agent dissolution apparatus which sprinkles water continuously to the solid phosphorus removal agent of this invention, (a) is a schematic plan view, (b) is CC of (a). The schematic sectional drawing of an arrow surface. BRIEF DESCRIPTION OF THE DRAWINGS It is an example which shows a waste water septic tank provided with the solid phosphorus removal agent melt | dissolution apparatus which continuously immerses the solid phosphorus removal agent of this invention in water, The schematic sectional drawing.

  The feature of the solid phosphorus removing agent described in the present invention is that the dissolution rate is delayed with respect to a substance that forms an insoluble or hardly soluble salt by reacting with phosphate ions in waste water, that is, a sustained release property is imparted. is there. And the main component of the solid phosphorus removal agent consists of a mixed substance containing an iron salt or an aluminum salt, a binder, and an essential oil as a liquid hydrophobic substance. Here, the liquid hydrophobic substance refers to a hydrophobic substance that is in a liquid state at a normal temperature level, and the natural fats and oils refer to vegetable oils and essential oils derived therefrom.

Examples of the iron salt or aluminum salt include iron salts such as ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride and hydrates thereof, aluminum sulfate, potassium aluminum sulfate, and sodium aluminum sulfate. And aluminum salts such as hydrates thereof, and the like. Among these compounds, non-deliquescent ones are preferable. In addition, although calcium salt, magnesium salt, etc. are mentioned, Preferably they are iron salt or aluminum salt.
When an iron salt is used in a wastewater treatment system, iron phosphate generated from phosphate ions and colloidal particles that are present aggregate to form a floc, but the compactness of this floc is good. That is, the suppression effect with respect to the increase in the accumulated sludge capacity becomes remarkable.
When an aluminum salt is used in a wastewater treatment system, aluminum phosphate produced from phosphate ions and colloidal particles that exist are aggregated to form flocs that accumulate, but even in highly reduced atmospheres Aluminum phosphate accumulates in a stable state.

  The binder includes a natural substance-derived polymer substance or derivative substance, and a water-soluble synthetic polymer substance. Polyvinyl alcohol resin which is a polymer having a hydroxy group or a polysaccharide such as starch, dextrin, cellulose, cellobiose, chitins, chitosans, etc. {Polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, polyvinyl acetal, etc.}, cellulose resins {methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose ( HEC), carboxymethylcellulose (CMC), hydroxypropylcellulose (HPC), hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, etc.}, Resin having ether bond {polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG), polyvinyl ether (PVE), etc.}, resin having carbamoyl group {polyacrylamide (PAAM), polyvinylpyrrolidone (PVP), Water-soluble resin such as polyacrylic acid hydrazide}. Since the application target is a wastewater (or sewage) septic tank, it is preferable that N atoms are not included in these substances.

  It is presumed that the above-mentioned binder also plays a role such as shape retention by a binder-like action when the kneaded compound is formed into a predetermined shape, and sustained release for delaying the dissolution rate. The said binder may mix | blend single or multiple types.

  The liquid hydrophobic substance is preferably oils and fats derived from natural products or essential oils thereof, and examples thereof include the following substances. Almond oil, flaxseed oil, avocado oil, sesame oil, olive oil, tung oil, walnut oil, sesame oil, rice bran oil, soybean oil, camellia oil, corn oil, rapeseed oil, palm oil, castor oil, safflower oil, palm oil, peanut Essential oils (aromatic oils) such as vegetable oils such as oil, fennel oil, orange oil, cinnamon oil, perilla oil, jasmine oil, camphor oil, turpentine oil, pine oil, mint oil, cypress oil, lavender oil, lemon oil . The liquid hydrophobic material can be expected to prevent water from entering the molded product. As a result, it has a function of slow release to slow down the dissolution rate and also serves as a lubricant during molding. I guess that.

  In addition to the binder and the liquid hydrophobic substance, fatty acid alkali metal salts, silica-containing substances and the like can be added as fillers. Examples of the fatty acid alkali metal salts include sodium salts and potassium salts such as capric acid, lauric acid, palmitic acid, stearic acid, and oleic acid, and these have a role as a lubricant during molding. Guessed. Examples of the silica-containing material include particulate materials such as fumed silica and amorphous silica, and liquid silica-containing materials such as sodium silicate and colloidal silica. These are presumed to play a role as binders, extenders and the like. It should be noted that liquid substances such as sodium silicate and colloidal silica often have alkalinity, and when mixed with an iron salt or an aluminum salt, some of them may form a metal hydroxide. A particulate material is preferred.

  Each of the components described above has the following blending ratio. When the iron salt (as a hydrate) is 100 parts by weight, the binder is preferably 10 to 30 parts by weight and the liquid hydrophobic substance 5 to 30 parts by weight. When adding a filler, it is preferable to set it as 5-15 weight part. By blending the binder in this range, the sustained release property and shape retention of the solid phosphorus removing agent can be enhanced. Further, by blending the liquid hydrophobic substance in this range, similarly, the sustained release can be improved and the smoothness at the time of molding can be obtained, and the compression of the liquid hydrophobic substance can be prevented particularly in compression molding.

  Further, when the aluminum salt (as a hydrate) is 100 parts by weight, the binder is preferably 3 to 15 parts by weight and the liquid hydrophobic substance 3 to 15 parts by weight. When adding a filler, it is preferable to set it as 1-5 weight part. By blending the binder in this range, the sustained release property and shape retention of the solid phosphorus removing agent can be enhanced. Further, by blending the liquid hydrophobic substance in this range, similarly, the sustained release can be improved and the smoothness at the time of molding can be obtained, and the compression of the liquid hydrophobic substance can be prevented particularly in compression molding.

Next, the manufacturing method of the solid phosphorus removal agent of this invention is demonstrated.
FIG. 1 is an exemplary process chart showing a method for producing a solid phosphorus removing agent comprising an iron salt or aluminum salt, a binder, and a liquid hydrophobic substance (or agent) according to the present invention. First, an iron salt or aluminum salt powder (including a hydrate) powder and a binder powder are introduced into a mixer and mixed. At this time, when both or one of them is a granular material, it is preferable to pulverize or pulverize the powder beforehand. As the mixer, a fixed mixer in which the container itself is fixed, a rotary mixer in which the container rotates, or the like can be used. Next, a step of introducing the mixture and the liquid hydrophobic substance into a kneading machine and kneading is performed. At this time, it is preferable to blend the liquid hydrophobic substance so that the kneaded compound does not enter an excessively melted state and has a hardness equal to or higher than a dough (dough-bread dough) state. In many cases, the fixed mixer has a kneading function, so that a liquid hydrophobic substance can be added to the mixture and kneaded.

  Next, a step of forming the kneaded compound into a predetermined shape is performed. Depending on the desired shape, the dough state of the kneaded compound, etc., the molding machine is properly used. For this molding, an extrusion (kneading) molding machine, an extrusion granulator, a compression molding machine, a tableting molding machine or the like is used. .

  Although the main purpose has been described for each of the basic steps in FIG. 1 so far, a series of a plurality of steps can be performed by one or two machines. For example, in kneading molding, powder raw materials (iron salt or aluminum salt, binder) are supplied to a mixer such as a V-type mixer or a ribbon mixer and sufficiently mixed. This mixture is transferred to a kneader such as a continuous kneader or an extruder, and a liquid raw material (liquid hydrophobic substance) is also introduced and kneaded, and the kneaded mixture is extruded. Subsequently, the extruded product is obtained by cutting.

Next, the method for dissolving the solid phosphorus removing agent of the present invention will be described.
In this method, water is continuously or intermittently sprinkled on the solid phosphorus removing agent and dissolved. Water is preferably sprayed like a shower falling from a punching plate, and is preferably sprayed over substantially the entire surface of the solid phosphorus removing agent in plan view. By carrying out like this, the whole solid phosphorus removal agent can be melt | dissolved stably. Here, the solid phosphorus removing agent is preferably composed of a mixed material of the iron salt or aluminum salt, a binder, and a liquid hydrophobic substance. If the relationship between the amount of water sprayed and the amount of the solid phosphorus removing agent dissolved is known in advance, the amount of iron salt or aluminum salt dissolved can be made substantially constant according to the amount of water sprayed. Water to be sprinkled may be tap water or treated water. For example, when watering tap water, a solution of iron salt or aluminum salt may be obtained in advance by watering, and this may be added to the water to be treated at a predetermined site. Since each ion of the dissolved iron salt or aluminum salt reacts with the existing phosphate ions, the treated water that has been sprinkled and passed may be transferred to a predetermined site.

Next, the dissolution apparatus for the solid phosphorus removing agent of the present invention will be described.
FIG. 2 shows an example of the solid phosphorus removing agent dissolving apparatus of the present invention, where (a) is a schematic plan view and (b) is a cross-sectional view taken along line AA of (a). The solid phosphorus remover dissolving apparatus 1 includes a support member 3 that supports the solid phosphorus remover 2, a storage container 4 that engages the support member 3 inside, a water sprinkling member 5 that sprinkles toward the solid phosphorus remover 2 from above, Is made up of. Further, the support member 3 is provided at a position where part or all of the solid phosphorus removing agent 2 is not submerged by the sprinkled water. From the water sprinkling member 5, water sprinkling is carried out continuously or intermittently, the solid phosphorus removing agent 2 is allowed to pass while being partially dissolved, and is discharged from the storage container 4.

  In FIG. 2, the solid phosphorus removing agent 2 has a cylindrical shape, but is not limited thereto. Further, a plurality of solid phosphorus removing agents 2 may be stacked or planarly arranged. Here, the solid phosphorus removing agent is preferably composed of a mixed material of the iron salt or aluminum salt, a binder, and a liquid hydrophobic substance. The solid phosphorus removing agent dissolving apparatus 1 and the water sprinkling member 5 are circular in plan view, but may be square. The bottom of the storage container 4 is open. Although the water sprinkling member 5 shows the case where it is supported by the water supply pipe, it may be supported by being engaged with a part of the solid phosphorus removing agent dissolving apparatus 1. Moreover, although the water sprinkling member 5 is accommodated in the solid phosphorus remover dissolving apparatus 1, it may be disposed above the solid phosphorus remover dissolving apparatus 1. Moreover, the water discharge part of the water sprinkling member 5 may have any shape such as a mesh plate shape, a punching plate shape, a slit plate shape, or the like, but is a shape that sprays water on substantially the entire surface (plan view) of the solid phosphorus removing agent 2. Or the structure is preferable. Although the support member 3 is stretched across the entire surface in the horizontal direction to the solid phosphorus remover dissolving apparatus 1, it may be partially stretched so that the solid phosphorus remover 2 does not fall. Moreover, although the supporting member 3 has shown the mesh shape, while supporting the solid phosphorus removal agent 2, it should just be a thing of the shape which the water to be sprinkled easily passes or falls.

  FIG. 3 is an example of another solid phosphorus removing agent dissolving apparatus, and shows a cross-sectional view thereof. A bottom plate is arranged at the bottom of the storage container 4 and a water collecting part 6 is provided. In this case, the passing water sprayed from the water sprinkling member 5 and in contact with the solid phosphorus removing agent 2 is collected by the water collecting section 6 at the bottom and transferred to another part (not shown). The bottom plate provided with the water collecting portion 6 may have an inclination like an inverted conical shape having the water collecting portion 6 as a vertex. Furthermore, the water collecting part 6 may not be at the center of the bottom plate but may be at the bottom of the side wall of the storage container 4.

  The method for dissolving another solid phosphorus removing agent in the present invention will be described. This is a method of dissolving a solid phosphorus removing agent by immersing it continuously or intermittently in water. The intermittent dipping means, for example, that a solid phosphorus removing agent is put in a container, water is supplied so that the solid phosphorus removing agent is immersed, and the water is removed so that the solid phosphorus removing agent is exposed after a predetermined time. Is discharged after a predetermined time has passed and water is supplied again. By doing so, the solid phosphorus removing agent can be dissolved stably. In addition, the immersion or exposure of the solid phosphorus removing agent may be the whole or a part of the solid phosphorus removing agent, but is preferably the whole. Here, the solid phosphorus removing agent is preferably composed of a mixed material of the iron salt or aluminum salt, a binder, and a liquid hydrophobic substance. If the relationship between the amount of water supplied and immersed and the amount of the solid phosphorus removing agent dissolved is known in advance, the amount of iron salt or aluminum salt dissolved can be made substantially constant. The supplied water may be tap water or treated water. For example, when supplying tap water, a solution of iron salt or aluminum salt may be obtained in advance by dipping, and this may be added to the water to be treated at a predetermined site. Since each ion of the dissolved iron salt or aluminum salt reacts with the existing phosphate ion, the discharged water to be treated may be transferred to a predetermined site.

Next, another solid phosphorus remover dissolving apparatus in the present invention will be described.
FIG. 4 is an example of another solid phosphorus removing agent dissolving apparatus in the present invention, (a) is a schematic plan view when the solid phosphorus removing agent is continuously immersed in water, and (b) is B in (a). It is -B sectional drawing. The solid phosphorus remover dissolving apparatus 1 is composed of a storage container 4 for storing the solid phosphorus remover 2, a water supply unit 7 for supplying and discharging water to the storage container 4, and a drainage unit 8. And the water supply / drainage mechanism is provided in the water supply part 7 and the waste_water | drain part 8 so that the solid phosphorus removal agent 2 may be immersed in water continuously. That is, while supplying water from the water supply part 7, the drainage part 8 is provided in the position where the solid phosphorus removal agent 2 is immersed. Here, the solid phosphorus removing agent is preferably composed of a mixed material of the iron salt or aluminum salt, a binder, and a liquid hydrophobic substance.
As shown in FIG. 4, when supplying water, the shielding plate 10 may be erected so that the water supplied from the water supply unit 7 does not directly collide with the solid phosphorus removing agent 2. 3 may be stretched in the lateral direction, and the solid phosphorus removing agent 2 may be placed thereon so as to be directed upward from below the support member 3.

  Moreover, in FIG. 4, although the solid phosphorus removal agent 2 has shown the column-shaped shape, it is not limited to this. Further, a plurality of solid phosphorus removing agents 2 may be stacked or planarly arranged. The solid phosphorus removing agent dissolving apparatus 1 is circular in plan view, but may be square. Although the support member 3 is stretched across the entire surface in the horizontal direction to the solid phosphorus remover dissolving apparatus 1, it may be partially stretched so that the solid phosphorus remover 2 does not fall. Moreover, although the supporting member 3 has shown the mesh shape, while supporting the solid phosphorus removal agent 2, what is necessary is just a thing of the shape through which water passes easily. The storage container 4 may be provided with means for stirring water.

FIG. 5 shows an example of a solid phosphorus removing agent dissolving apparatus when the solid phosphorus removing agent is intermittently immersed in water.
(A) is a schematic sectional drawing of the state in which the solid phosphorus removing agent is immersed in water, (b) is a schematic sectional view of the state in which the solid phosphorus removing agent is exposed. In the relationship between the water supply unit 7 and the drainage unit 8, the drainage unit 8 is provided with a siphon tube 11 so that water can be discharged by a siphon phenomenon. That is, when water is supplied from the water supply unit 7, the inside of the storage container 4 and the inside of the siphon tube 11 are filled, and the solid phosphorus removing agent 2 is immersed. When the water level further rises and reaches the upper part of the siphon tube 11, the siphon works at once and the water in the storage container 4 is discharged. Thereby, the solid phosphorus removing agent 2 is exposed. By repeating this, the solid phosphorus removing agent 2 is intermittently immersed in water. The means for intermittent immersion is not limited to a siphon tube, and an electromagnetic valve or the like can also be used.
Further, as shown in FIG. 5, when supplying water, the shielding plate 10 may be erected so that the water supplied from the water supply unit 7 does not directly collide with the solid phosphorus removing agent 2. 3 may be stretched in the lateral direction, and the solid phosphorus removing agent 2 may be placed thereon so as to be directed upward from below the support member 3.

  In FIG. 5, the solid phosphorus removing agent 2 has a cylindrical shape, but is not limited thereto. Further, a plurality of solid phosphorus removing agents 2 may be stacked or planarly arranged. The solid phosphorus removing agent dissolving apparatus 1 is circular in plan view, but may be square. Although the support member 3 is stretched across the entire surface in the horizontal direction to the solid phosphorus remover dissolving apparatus 1, it may be partially stretched so that the solid phosphorus remover 2 does not fall. Moreover, although the supporting member 3 has shown the mesh shape, while supporting the solid phosphorus removal agent 2, what is necessary is just a thing of the shape through which water passes easily. The storage container 4 may be provided with means for stirring water.

Next, a drainage septic tank equipped with the solid phosphorus removing agent dissolving apparatus of the present invention will be described.
FIG. 6: is an example of the waste water septic tank provided with the solid phosphorus removal agent melt | dissolution apparatus which sprinkles water continuously, (a) is a schematic plan view, (b) is the schematic of CC plane of (a). A cross-sectional view is shown. The waste water purification tank 15 incorporates an anaerobic treatment tank (a first anaerobic treatment tank 16 and a second anaerobic treatment tank 17) and an aerobic treatment tank 18, and a solid phosphorus removing agent in the space inside the inside thereof. A melting apparatus 1 is provided. FIG. 6 shows a waste water purification tank in which the anaerobic treatment tank and the aerobic treatment tank 18 are integrated, but the anaerobic treatment tank and the aerobic treatment tank 18 are incorporated as a system. There may be.

  In FIG. 6, the solid phosphorus removing agent dissolving apparatus 1 is provided at the end of the circulating water channel 21 that returns the advection water after passing through the aerobic treatment tank 18 to the first anaerobic treatment tank 16, and is connected to the water spray member 5. Yes. The solid phosphorus removing agent dissolving apparatus 1 may be provided in the upper part of the second anaerobic treatment tank 17 or the upper part of the aerobic treatment tank 18 in the circulation channel 21. Further, it may be provided near the outlet portion of the transfer pump 31 (upper part of the aerobic treatment tank 18), and the outlet and the water sprinkling member 5 may be connected. If the solid phosphorus removal agent 2 is divalent like ferrous sulfate, it will be oxidized to trivalent and easily react with phosphate ions if it has dissolved oxygen or is subjected to a high oxidation-reduction potential. It is. In addition, although the solid phosphorus removing agent dissolution apparatus 1 is provided in an above-described site | part, it is preferable to provide below the manhole 36 of the waste water purification tank 15 in view of the replenishment property of the solid phosphorus removing agent 2.

  In FIG. 6, advection water is returned to the anaerobic treatment tank from the settling tank 19 (or treated water tank) after passing through the aerobic treatment tank 18, and a return pump 22 is used for this return means. The circulating water pumped up by the return pump 22 flows down the circulating water passage 21 connected at the upper part thereof and enters the water sprinkling member 5 of the solid phosphorus removing agent dissolving apparatus 1. The circulating water sprayed by the water sprinkling member 5 comes into contact with the solid phosphorus removing agent 2 and dissolves the solid phosphorus removing agent 2, while the first anaerobic state from the water collecting part 6 of the storage container 4 of the solid phosphorus removing agent dissolving apparatus 1. It enters the inflow baffle 25 provided in the upper part of the processing tank 16.

  Circulating water that has entered the first anaerobic treatment tank 16 from the inflow baffle 25 is mixed with the in-bath water, but phosphate ions contained in the circulating water react with dissolved iron ions or aluminum ions to become insoluble or difficult. A soluble phosphate is formed. And it is separated and accumulated by adhering to suspended matter (SS) in the water in the tank and agglomerating or adhering to sludge. At this time, the circulating water may be returned to the second anaerobic treatment tank 17. As the circulating water after leaving the aerobic treatment tank 18, the water in the settling tank 19 (or the treated water tank) is pumped up, but it is drawn up from the bottom of the aerobic treatment tank 18. May be.

  In the case of a wastewater septic tank equipped with a solid phosphorus removing agent dissolving device that intermittently sprinkles water, a bypass that does not connect to the solid phosphorus removing agent dissolving device is provided in the circulation channel 21, and the flow path is switched by a switching valve, or a return pump 22 Can be intermittently sprayed (not shown).

  Here, the waste water purification tank 15 will be described in more detail. The anaerobic treatment tank is composed of a first anaerobic treatment tank 16 and a second anaerobic treatment tank 17, and the first anaerobic treatment tank 16 has an inlet 26. Is provided. Further, a box-shaped inflow baffle 25 having upper and lower openings is provided below the inflow port 26, and an advection pipe 27 (or an advection port) is provided on the partition wall opposite to the inflow port 26. . The first anaerobic treatment tank 16 precipitates and separates solid matter that tends to settle in the inflowing sewage, and concentrates and stores it at the bottom of the tank. At this time, a part of the sludge stored at the bottom of the tank becomes scum by an anaerobic biological reaction, rises and is stored at the top of the tank. Moreover, in the filter bed 28, an anaerobic biological reaction is advanced. At the same time, the circulating water flowing from the circulating water channel 21 is also mixed, and the generated phosphate particles are separated and accumulated together with sludge and SS.

  The second anaerobic treatment tank 17 has a processing function similar to that of the first anaerobic treatment tank 16, and stores sludge at the top of the tank by scumming, an anaerobic biological reaction at the filter bed 29, and the bottom of the tank. Store sedimented sludge. In addition, the remaining phosphate particles are separated and accumulated together with the sludge. An advection pipe 30 is provided on the partition wall on the aerobic treatment tank 18 side, and a transfer pump 31 is attached in the advection pipe 30. In the above anaerobic treatment tanks (first anaerobic treatment tank 16 and second anaerobic treatment tank 17), most of the nitrogen content contained in the water to be treated is converted to ammonia nitrogen as the organic matter is decomposed. Note that the filter bed 28 and the filter bed 29 may not be necessary, and can be removed in that case.

  In each upper part of the first anaerobic treatment tank 16 and the second anaerobic treatment tank 17, the liquid level is the highest water level (HWL) in order to reduce the fluctuation of the inflowing wastewater and transfer it to the next tank. And a flow rate adjusting unit 32 that can vary between the lowest water level (LWL). In this case, the water level in the first anaerobic treatment tank 16 and the second anaerobic treatment tank 17 depends on whether the inflow amount of the waste water is larger or smaller than the liquid feed amount of the transfer pump 31. W. L and H.H. W. It fluctuates between L. The waste water purification tank 15 is provided with a flow rate adjusting unit 32 to average the amount of inflow of waste water, and anaerobic treatment tanks (first anaerobic treatment tank 16, second anaerobic treatment tank 17), aerobic treatment tank 18 and the like. Each function of each tank is exhibited well. In this embodiment, the transfer pump 31 is an air lift pump that uses air supplied from the blower 24, but an intermittent metering pump that pumps air into a sealed container, an electric submersible pump, or the like can also be used.

  The aerobic treatment tank 18 has an aeration tube 33 for aeration arranged at the bottom, and ejects air supplied from the blower 24. The aerobic treatment tank 18 forms a bed filled with a microorganism adhesion material (also referred to as a carrier, a microorganism carrier, a contact material, or a contact filter material). Here, the bed filled with the microorganism adhesion material is a fluidized bed that flows together with the liquid by the air ejected from the microorganism adhesion material, a fixed bed in which only the liquid moves, or a combination of both the fluidized bed and the fixed bed. Also good. The aerobic treatment tank 18 performs aeration so that the microorganism-adhering material (with microorganisms attached) and the liquid are sufficiently mixed, or the microorganism-adhering material and the liquid are in positive contact with each other. Organic matter is oxidized and decomposed, ammonia nitrogen is nitrified (nitrite ion, nitrate ion), and phosphorus content becomes phosphate ion.

  The shape of the microorganism-adhering material can be various, such as plate-like, net-plate-like, loofah-like, porous, cylindrical, rod-like, skeletal spherical, string-like, and granular, irregular lump, cube, fiber lump, etc. What was processed into the shape can be used. Of these microorganism-adhering materials, those having a shape that is relatively small and easy to flow are preferably used for the fluidized bed, and those having a shape that is difficult to block and fix by the adhering microorganisms or particles are used for the fixed bed. Preferably used. The material of the microbial adhesion material is made of synthetic resin such as vinylidene chloride, polyvinyl formal, polyurethane, melamine resin, inorganic processed material such as ceramics and silica sand, fossil processed material such as anthracite, activated carbon, etc. Any one having one or more, a polyolefin resin such as polyethylene and polypropylene, polystyrene, and the like having a specific gravity of about 1 or 1 or less can be used.

  At the bottom of the aerobic treatment tank 18, there is an opening (advection port) 34 that communicates with the settling tank 19 (or the treated water tank). The settling tank 19 is provided with a return pump 22 that pumps up a part of the aerobic treated water treated in the aerobic treatment tank 18 as circulating water. The return pump 22 is connected to the circulating water channel 21 at the upper part thereof. By providing the return pump 22, in addition to removing phosphate ions, the circulating water is returned by the return pump 22, so that the suspended SS or sediment in the aerobic treatment tank 18 or the settling tank 19 is present. If sludge can be extracted, or if there is nitrite nitrogen or nitrate nitrogen, nitrogen can be removed by biological action in the first anaerobic treatment tank 16 and the second anaerobic treatment tank 17. The return of the circulating water from the return pump 22 may be continuous or intermittent. In the present embodiment, the return pump 22 is an air lift pump that supplies air from the blower 24. However, an intermittent metering pump, an electric pump, or the like that pumps air into a sealed container can also be used.

  Above the settling tank 19, there is a disinfection tank 20 that disinfects and discharges treated water from which phosphate ions, nitrogen, and organic substances have been removed. The disinfection tank 20 faces a discharge port 35.

  Next, an operation method of the drainage septic tank 15 will be described. The inflow wastewater enters the first anaerobic treatment tank 16 from the inlet 26 as indicated by solid line arrows in FIG. 5, where solid-liquid separation and anaerobic biological treatment are performed. The advection liquid that has passed here enters the second anaerobic treatment tank 17, and further undergoes solid-liquid separation and anaerobic biological treatment. Further, in the flow rate adjustment unit 32, the wastewater is transferred to the next aerobic treatment tank 18 by the transfer pump 31 while absorbing and mitigating fluctuations in the amount of wastewater flowing into the first anaerobic treatment tank 16 and the second anaerobic treatment tank 17. Transport quantitatively.

  The advection water flowing into the aerobic treatment tank 18 is subjected to aerobic biodegradation by the air discharged from the aeration tube 33 and the microorganism adhesion material. A part of the decomposed organic matter in the sewage adheres to the microorganism-adhering material while being converted into microorganisms, and a part of the organic matter floats in the liquid and exists as SS. The advection water that has exited the aerobic treatment tank 18 enters the precipitation tank 19 from the lower opening 34. Here, a part of the advection water is transferred to the solid phosphorus removing agent dissolving apparatus 1 through the circulating water channel 21 continuously or intermittently by the return pump 22 as circulating water. The circulating water dissolves the solid phosphorus removing agent 2 and enters the first anaerobic treatment tank 16, and the phosphate ion is accumulated as a hardly soluble or insoluble salt. The remaining advection water enters the disinfection tank 20 from the overflow port at the top of the settling tank 19. The disinfected advection water (treated water) is discharged from the discharge port 35 to the outside of the system.

Next, a drainage septic tank provided with another solid phosphorus removing agent dissolving apparatus of the present invention will be described.
FIG. 7 is an example of a drainage septic tank provided with a solid phosphorus removing agent dissolving device for continuously immersing the solid phosphorus removing agent in water, and shows a schematic cross-sectional view thereof. The plan view is similar to FIG. The drainage purification tank 15 incorporates an anaerobic treatment tank (a first anaerobic treatment tank 16 and a second anaerobic treatment tank 17) and an aerobic treatment tank 18, and integrates these tanks. In the space, a solid phosphorus removing agent dissolving apparatus 1 is provided.

  In FIG. 7, the solid phosphorus removing agent dissolving apparatus 1 is provided at the end of the circulation water channel 21 for returning the advection water after passing through the aerobic treatment tank 18 to the first anaerobic treatment tank 16. Since the structure and structure of the waste water septic tank are the same as those in FIG. 6, the different parts will be described. The circulating water pumped up by the return pump 22 flows down the circulating water passage 21 connected at the upper part thereof and enters the water supply unit 7 of the solid phosphorus removing agent dissolving apparatus 1. Here, the circulating water enters the inflow baffle 25 provided in the upper part of the first anaerobic treatment tank 16 from the drainage part 8 while immersing the solid phosphorus removing agent 2 and simultaneously dissolving the solid phosphorus removing agent 2. .

  In the case of a wastewater septic tank equipped with a solid phosphorus removing agent dissolving device that intermittently immerses the solid phosphorus removing agent in water, intermittent immersion is achieved by providing means such as a siphon tube 11 in the drainage section 8 ( (Not shown). The configuration, structure, and operation method of the drainage septic tank 15 are the same as those in FIG.

Hereinafter, the present invention will be described specifically by way of examples.
(Examples 1-7)
A solid phosphorus removing agent was produced according to the production method shown in FIG. Ferrous sulfate heptahydrate (Kanto Chemical Co., Inc., reagent grade 1) was used as the iron salt. Examples of binders include dextrin (Kanto Chemical Co., Ltd., reagent grade 1), polyethylene oxide (Sumitomo Seika Co., Ltd., PEO-8Z), polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd., NM-14), and polyvinyl acetal (Sekisui Chemical Co., Ltd.). KS-10), fumed silica (Tokuyama QS-09, MT-10) and sodium laurate (Kanto Chemical Co., Ltd., reagent grade 1) were used as fillers. Moreover, pine oil (Sanei Chemical Co., Ltd.) was used for the liquid hydrophobic substance. The components and blending ratios of Examples 1 to 7 are shown in Table 1 (1).

(mixture)
Ferrous sulfate heptahydrate previously ground in a mortar was transferred to a homogenizer and mixed with a binder or further filler. When there were a plurality of types of binders, one type was mixed for a predetermined time for each addition and sequentially added.
(Kneading)
A liquid hydrophobic substance was put into the mixture and kneaded for a predetermined time. In addition, since the homogenizer was used, all of the kneaded compounds were in the form of lumps (flakes) having a hardness higher than the dough state.
(Molding)
The kneaded mixture was taken out and about 5 g was compressed with a hand press type tablet molding machine at a cylinder pressure of 30 MPa to obtain a cylindrical tablet having a diameter of 20 mm and a height of 11 mm, that is, a solid phosphorus removing agent.

(Comparative Example 1)
A tablet composed of ferrous sulfate heptahydrate (same as in the example) and dextrin as a binder (same as in the example) is referred to as comparative example 1, and the blending ratio is shown in Table 1 (1).
(mixture)
Ferrous sulfate heptahydrate previously ground in a mortar was transferred to a homogenizer, and dextrin was added to this and mixed.
(Molding)
5 g of this mixed powder was compression molded at a cylinder pressure of 40 MPa using a hand press type tablet molding machine to obtain a cylindrical tablet having a diameter of 20 mm and a height of 11 mm.

(Solubility test)
A dissolution test was conducted as a sustained release evaluation. The tablets prepared in Examples 1 to 7 and Comparative Example 1 were placed in a vinyl chloride tray having a width of 23 mm and a length of 60 mm for each test, and 10 ml / min of tap water from the upstream side of the tray was 10 by a metering pump. Feed continuously for minutes. At this time, a height of about 2 mm from the lower end of the tablet was in contact with tap water. After contact with the tablet, the container received the total amount of effluent flowing from the tray. And the iron ion density | concentration melt | dissolved in effluent water was measured, and the melt | dissolution amount of the tablet was computed from the content rate of the iron content in a tablet. The dissolution test results of the tablet are shown in Table 1 (2). In addition, a digital simple water quality meter (Kyoritsu Riken, Inc., Λ-8000 type) was used for the measurement of the iron ion concentration.

  From Table 1, when the dissolution rate ratio of the tablet (VS Comparative Example 1 ratio) is seen, Examples 1 to 7 show values of 1/10 or less of Comparative Example 1, respectively. That is, the solid phosphorus removing agent comprising ferrous sulfate heptahydrate, a binder, and a liquid hydrophobic substance has a remarkable sustained release property.

(Examples 8 to 11)
A solid phosphorus removing agent was produced according to the production method shown in FIG. As the aluminum salt, potassium aluminum sulfate dodecahydrate (hereinafter, abbreviated as “Kari Alum”) (Kanto Chemical Co., Ltd., reagent grade 1) was used. Ethyl cellulose (Nisshin Kasei Co., Ltd. Etcel STD-4) was used as the binder, and pine oil (Sanei Chemical Co., Ltd.) was used as the liquid hydrophobic substance. The components and blending ratios of Examples 8 to 11 are shown in Table 2 (1).

(mixture)
Potash alum previously ground in a mortar was transferred to a homogenizer, and ethyl cellulose was added thereto and mixed.
(Kneading)
The mixture was transferred to a mortar, pine oil was added thereto, and kneaded for a predetermined time. The kneaded compound was wet and granular.
(Molding)
Using 5 g of each of the kneaded compounds, compression molding was performed at a cylinder pressure of 25 MPa with a hand press type tablet molding machine to obtain a cylindrical tablet having a diameter of 20 mm and a height of 11 mm, that is, a solid phosphorus removing agent.

(Comparative Examples 2 to 4)
Tablets consisting only of potassium alum and ethyl cellulose, potassium alum and pine oil, and potassium alum are referred to as Comparative Examples 2, 3, and 4, and the blending ratio is shown in Table 2 (1).

(mixture)
In the case of potash alum and ethyl cellulose, potash alum previously ground in a mortar was transferred to a homogenizer, and ethyl cellulose was added to this and mixed. The mixture was powdery.
(Kneading)
In the case of potash alum and pine oil, the potash alum was first put in a mortar and pulverized, then the pine oil was put into this and kneaded for a predetermined time. The kneaded compound was wet and granular.
(Molding)
About 5 g of each of the mixture, the kneaded mixture and the pulverized potash alum were compression-molded at a cylinder pressure of 25 MPa by a hand press type tablet press, and a cylindrical tablet having a diameter of 20 mm and a height of 10 mm, ie, removal of solid phosphorus An agent was obtained.

(Solubility test)
A dissolution test was conducted as a sustained release evaluation. The test equipment described above was used. From the upstream side of the tray, 10 ml / min of tap water was continuously supplied for 15 minutes by a metering pump. At this time, a height of about 1 mm from the lower end of the tablet was in contact with tap water. After contact with the tablet, the container received the total amount of effluent flowing from the tray. And the sulfate ion density | concentration melt | dissolved in the outflow water was measured, and the melt | dissolution amount of the tablet was computed from the content rate of the sulfuric-acid content in a tablet. The dissolution test results of the tablet are shown in Table 2 (2). In addition, a digital simple water quality meter (Kyoritsu Riken, Inc., Λ-8000 type) was used for measurement of sulfate ion concentration.

  From Table 2, when the dissolution rate ratio of the tablet (VS comparison example 4 ratio) is seen, in comparison with the comparison example 4, each of the examples 8 to 11 shows a value of about 1/4 or less. That is, the solid phosphorus removing agent composed of potash alum, binder and liquid hydrophobic substance has a remarkable sustained release property.

  1: Solid phosphorus remover dissolving device, 2: Solid phosphorus remover, 3: Support member, 4: Storage container, 5: Sprinkling member, 6: Water collecting part, 7: Water supply part, 8: Drainage part, 10: Shielding Plate, 11: Siphon tube, 15: Waste water purification tank, 16: First anaerobic tank, 17: Second anaerobic tank, 18: Aerobic tank, 19: Settling tank, 20: Disinfection tank, 21: Circulation Water channel, 22: return pump, 24: blower, 25: inflow baffle, 26: inlet, 27: advection pipe, 28: filter bed, 29: filter bed, 30: advection pipe, 31: transfer pump, 32: flow rate adjustment Part, 33: diffuser, 34: opening, 35: outlet, 36: manhole cover.

Claims (5)

  A solid phosphorus removing agent comprising an iron salt or aluminum salt, a binder, and vegetable oil as a liquid hydrophobic substance.   The solid phosphorus removing agent according to claim 1, wherein the vegetable oil is an essential oil derived therefrom.   The solid phosphorus removing agent according to claim 2, wherein the essential oil is pine oil. 2. The solid phosphorus removing agent according to claim 1, wherein the binder is a polymer substance or derivative substance derived from a natural product, or a water-soluble synthetic polymer substance.   A drainage septic tank comprising the solid phosphorus removing agent according to any one of claims 1, 2, 3, and 4.

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