JP6523183B2 - Water treatment method, water treatment apparatus and water treatment system - Google Patents

Description

  Embodiments of the present invention relate to a water treatment method, a water treatment apparatus and a water treatment system.

  Recently, with the development of industry and the increase of population, effective use of water resources is required. In order to make effective use of water resources, it is important to purify and reuse various types of drainage such as industrial drainage and domestic drainage. In order to purify the waste water, it is necessary to separate and remove water insolubles and impurities contained in water.

Examples of a method of separating an organic substance contained in water include an oxidation treatment using ozone or the like, and an accelerated oxidation treatment that generates an active species called OH radical. In particular, the accelerated oxidation treatment is used as advanced drainage treatment because organic substances can be decomposed to carbon dioxide by the strong oxidizing power of OH radicals. Examples of the accelerated oxidation treatment include ozone + hydrogen peroxide, ozone + ultraviolet light, ozone + hydrogen peroxide + ultraviolet light, iron ions + hydrogen peroxide (Fenton reaction), ozone + catalyst, ultraviolet light + photocatalyst and the like.
The catalyzed accelerated oxidation process has the advantage of not adding the drug into water, and various studies have been conducted. For example, a water treatment method is known in which manganese dioxide generated by ozone treatment is removed by biofiltration after adding a coagulant containing manganese or a manganese compound to treated water and performing ozone treatment in the presence of manganese ions ing.

  However, in the water treatment method in which the catalyst is added to the water to be treated, it is difficult to control the activity of the catalyst, the activity of the catalyst is lowered, and the removal efficiency of the organic matter may be lowered.

Patent No. 3178975 gazette

  The problem to be solved by the present invention is to provide a water treatment method, a water treatment apparatus and a water treatment system capable of efficiently removing organic substances in water by accelerated oxidation.

A water treatment method according to an embodiment is a water treatment method for removing organic matter in raw water containing organic matter by accelerated oxidation, which comprises the steps of preparing manganese ion-containing treated water, and generating manganese ion-containing treated water It has a step and a step of recovering manganese ions.
In the step of preparing the manganese ion-containing treated water, manganese ions are supplied to the raw water to prepare a manganese ion-containing treated water having a manganese ion concentration of 0.01 mg / L or more and 10 mg / L or less. In the step of generating the manganese ion-containing treated water, X being the pH value of the manganese ion-containing treated water and Y (unit: V) being the oxidation reduction potential value measured using a standard hydrogen electrode as a comparison electrode A pH adjuster and ozone are supplied to the manganese ion-containing treated water such that organic ions in the manganese ion-containing treated water are removed by accelerated oxidation so that the manganese ion-containing treated water satisfies the following formula. To generate
2 ≦ X ≦ 5
0.8 ≦ Y ≦ 1.5-0.08 × X
In the step of recovering manganese ions, manganese ions in the manganese ion-containing treated water are recovered.

The theoretical phase diagram (Eh-pH diagram) which shows the form of manganese in the thermodynamic equilibrium state of manganese aqueous solution. The phase diagram which shows the form of manganese in manganese aqueous solution containing organic substance. The graph which shows a time-dependent change of Eh and ozone concentration when ozone is continuously supplied, maintaining pH at 2 about manganese solution containing an organic matter. The graph which shows a time-dependent change of Eh and ozone concentration when ozone is continuously supplied, maintaining pH at 3.6 about manganese solution containing organic matter. The schematic diagram of the water treatment system which concerns on 1st Embodiment. The schematic diagram of the water treatment system which concerns on 2nd Embodiment. The schematic diagram of the water treatment system which concerns on 3rd Embodiment. 6 is a graph showing the relationship between the manganese ion concentration measured in Example 1 and the decomposition efficiency of an organic substance.

  Hereinafter, a water treatment method, a water treatment apparatus, and a water treatment system of the embodiment will be described with reference to the drawings.

FIG. 1 is a theoretical phase diagram (Eh-pH diagram) showing the form of manganese in the thermodynamic equilibrium state of a manganese aqueous solution (Source of FIG. 1: Geological Survey of Japan Research Material Collection, No. 419, Internet <URL Https://www.gsj.jp/data/openfile/no0419/openfile419j. Pdf>).
In FIG. 1, the horizontal axis represents the pH of the aqueous manganese solution, and the vertical axis represents the redox potential (hereinafter referred to as Eh) of the aqueous manganese solution measured using a standard hydrogen electrode as a comparison electrode. From the theoretical phase diagram of FIG. 1, it can be seen that the manganese ion in the aqueous manganese solution takes various forms depending on pH and Eh.

As a result of repeated investigations focusing on the fact that the form of manganese ion in a manganese aqueous solution depends on pH and Eh, the inventors have found that under certain conditions, as shown by the following reaction formula, It is found that the intermediate [MnO] ²⁺ which has not been formed is thermodynamically generated, and the pH value and Eh value regions optimum for removing organics in water by accelerated oxidation in the presence of manganese ions Was found to exist. It is speculated that this [MnO] ²⁺ particularly has a feature of spontaneously reacting with unsaturated hydrocarbons to promote decomposition.

Mn ²⁺ + O ₃ → [MnO] ²⁺ + O ₂ + H ₂ O
ΔE = −39.6 kcal / mol

The above findings are described with reference to FIGS.
FIG. 2 is a phase diagram showing the form of manganese in an aqueous manganese solution containing an organic substance (measured value). In FIG. 2, the horizontal axis is the pH of the aqueous manganese solution, and the vertical axis is the Eh of the aqueous manganese solution. The pH was adjusted by a pH adjuster, and Eh was adjusted by ozone.
When the pH value (X) of the manganese aqueous solution is 2 ≦ X ≦ 5 and the Eh value (Y) is 0.8 ≦ Y ≦ 1.5-0.08X, that is, the pH value and the Eh value are When it is in the region of (II), the removal efficiency of the organic matter by the accelerated oxidation is high. This is reacted manganese ions in the aqueous solution of manganese is ozone takes [MnO] ²⁺ form, by the [MnO] ²⁺ is to react with the organic material is believed to be due to the removal of organic substances is accelerated .

When the Eh value is higher than the region (II), for example, in the region (I), the form of manganese in water becomes MnO ₄ ⁻ (permanganic acid). Permanganic acid also decomposes an organic substance as an oxidizing agent, but decomposition is faster due to accelerated oxidation when the Eh value is in the range of (II). On the other hand, if the Eh value is lower than the region (II), no accelerated oxidation occurs or it is too late to be used for water treatment.

If the pH value is lower than the region (II), the pH becomes too low, and a large amount of drug is required to adjust the pH, and a material having high acid resistance needs to be used as a component of the device. Not desirable. On the other hand, if the pH value is larger than the region of (II), for example, if it is in the region of (III), manganese is likely to take the form of MnO ₂ (S) and there is no accelerated oxidation at all or It is late and can not be used for water treatment. When an aqueous manganese solution having a pH value and an Eh value in the range of (III) is brought into contact with the manganese compound particles, manganese ions in the aqueous manganese solution are precipitated on the surface of the manganese compound particles and easily adsorbed.

FIG. 3 is a graph showing temporal changes in Eh and ozone concentration of the aqueous manganese solution when ozone is continuously supplied to the aqueous manganese solution containing organic substances while maintaining the pH of the aqueous manganese solution at 2. FIG. 4 is a graph showing temporal changes in Eh and ozone concentration of the manganese aqueous solution when ozone is continuously supplied to the manganese aqueous solution containing an organic substance while maintaining the pH of the manganese aqueous solution at 3.6.
As shown in FIGS. 3 and 4, when ozone is supplied to the manganese aqueous solution, the ozone concentration initially increases with the passage of time, but then decreases. On the other hand, the Eh value rises sharply at the same time when the ozone concentration starts to decrease, and then shows a nearly constant value. The ozone concentration decreases because ozone is consumed by the reaction of manganese ions in the manganese aqueous solution with ozone to generate [MnO] ²⁺ . Therefore, while the ozone concentration decreases and the Eh value shows a constant value, it is considered that the decomposition and removal of the organic substance is progressing by the accelerated oxidation. As time passes further, ozone concentration and Eh value turn to rise. The ozone concentration increases because the removal of the organic matter in the aqueous manganese solution eliminates the need for [MnO] ²⁺ , and the ozone is not consumed and remains in the aqueous manganese solution. The Eh value increases because the form of manganese ions becomes MnO ^{4 − as} the ozone concentration increases.

  The water treatment method of the embodiment based on the above findings has a step of preparing manganese ion-containing treated water, a step of generating manganese ion-containing treated water, and a step of collecting manganese ions.

  The manganese ion-containing treated water has a manganese ion concentration in the range of 0.01 mg / L to 10 mg / L. If the manganese ion concentration is lower than the above range, the substantial catalytic effect may be reduced. On the other hand, if the manganese concentration is higher than the above range, recovery of manganese from water may be difficult.

In the step of preparing the manganese ion-containing treated water, the manganese ion-containing treated water supplies the pH adjuster and ozone to the raw water, and the pH value (X) and the Eh value (Y) of the raw water are as follows. The raw water can be prepared by bringing manganese ions into contact with the raw water by bringing the raw water into contact with the manganese compound particles while adjusting to satisfy the formula. Manganese elutes as MnO ⁴⁻ by adjusting the pH value (X) of the raw water and the Eh value (Y) to satisfy the following equation.
2 ≦ X ≦ 5
1.5-0.08 × X <Y

Examples of the manganese compound constituting the manganese compound particles include manganese oxide (eg, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ ), ferrite containing manganese (eg, manganese ferrite MnFe ₂ O ₄ ), manganese And ore. Moreover, the filtration sand which coated the manganese compound on the surface can also be used as a manganese compound particle. The manganese ion concentration of the manganese ion-containing treated water can be adjusted by adjusting the contact time between the raw water and the manganese compound and the pH and the Eh of the raw water.
In addition, preparation of a manganese ion containing to-be-processed water can also be performed by mixing raw water and manganese aqueous solution.

Further, in the step of recovering manganese ions, manganese ions in the manganese ion-containing treated water are supplied with a pH adjuster and an oxidizing agent such as ozone or hypochlorous acid to the manganese ion-containing treated water to carry out manganese ion-containing treatment The pH value (X) and the Eh value (Y) of water are adjusted so as to satisfy the following equation (that is, within the range of (III) in FIG. 2), It can collect | recover by making a manganese adsorbent particle contact and making a manganese adsorbent particle adsorb | suck a manganese ion.
5 <X ≦ 9
0.6 ≦ Y ≦ 1.5-0.08 × X

  Manganese compound particles and ion exchange resins can be used as the manganese adsorbent particles.

There is no particular limitation on the type of organic substance in the raw water removed by the water treatment method of the embodiment. As a result of studies by the present inventors, it has been found that the active species [MnO] ²⁺ formed by the reaction of Mn ²⁺ and ozone particularly plays a particularly prominent role in the decomposition of the organic substance having a carbon unsaturated bond. Therefore, the water treatment method of an embodiment is effective in removal of the organic matter which has a carbon unsaturated bond. Examples of the organic substance having a carbon unsaturated bond include a compound having a benzene ring represented by phenol and the like, and a carboxylic acid represented by oxalic acid and the like. Among these organic substances, there are substances that are difficult to be decomposed by oxidative decomposition of only ozone, but in the water treatment method of the embodiment, since the organic substances are decomposed by oxidation promotion using [MnO] ²⁺ as a catalyst, these organic substances It can be removed quickly.

  Next, embodiments of the water treatment method, the water treatment apparatus, and the water treatment system configured based on the above findings will be described in more detail.

First Embodiment
FIG. 5 is a schematic view of the water treatment system according to the first embodiment.
The water treatment system 1 according to the first embodiment shown in FIG. 5 includes a raw water storage tank (not shown), an accelerated oxidation tank 10, a first packed tower (manganese ion supply device) 20a, and a second packed tower (manganese ion recovery device). 20 b and a controller 102.
A raw water storage tank is a tank for storing raw water containing organic matter.

  The first packed column 20a is an apparatus for supplying manganese ions to raw water to prepare manganese ion-containing treated water. The first packed tower 20 a is connected to the raw water storage tank via the pipe 301. The pipe 301 includes a pump 50a, a three-way valve 60a, an ozone supply pipe 40a, and a pH adjuster supply pipe 41a. A pipe 302 branches from the three-way valve 60a, and the pipe 302 is connected to a treatment water tank (not shown). The ozone supply pipe 40a is a pipe for supplying ozone. Ozone is supplied in the form of gas. Although ozone is generated and supplied by an ozone generator (not shown), air or oxygen can be used as the raw material at this time. The pH adjuster supply pipe 41a is a pipe for supplying a pH adjuster such as an acid, an alkali, or a buffer. An example of the acid is sulfuric acid. Sodium hydroxide is mentioned as an example of an alkali. Examples of buffers include phosphate buffers.

  The first packed column 20a is packed with manganese compound particles 201a. The shape of the manganese compound particles 201a is not particularly limited as long as there is no hindrance to water flow, but it is preferable that the particles have an average particle diameter in the range of 0.1 to 5 mm. The water flow direction of the first packed tower 20a is not particularly limited, and may be either upward or downward. Also, the water flow direction may be a lateral direction. The first packed column 20a is provided with a sensor (not shown) for measuring pH and Eh.

  The promotion oxidation tank 10 is a tank which removes the organic substance in the manganese ion containing to-be-processed liquid prepared by the 1st packing tower 20a by promotion oxidation, and produces | generates a manganese ion containing treated water. The promoting oxidation tank 10 is connected to the first packed tower 20 a via a pipe 303. The pipe 303 includes a pump 50c, an oxidant supply pipe 40d, and a pH adjuster supply pipe 41d. The oxidizing agent supply pipe 40d is a pipe for supplying an oxidizing agent such as ozone and hypochlorous acid. The pipe 303 further has a pipe 304 connected via the three-way valves 60b and 60c. The pipe 304 is a bypass when the pump 50c is not used.

In the promoting oxidation tank 10, a stirrer 101 for stirring the manganese ion-containing liquid stored in the promoting oxidation tank 10 is installed. The shape, capacity, material and the like of the promoting oxidation tank 10 can be appropriately determined according to the application of the water treatment system 1 and the like. The promoting oxidation tank 10 is not particularly limited, but is preferably made of vinyl chloride or stainless steel which is resistant to ozone.
Moreover, the sensor 103 which measures pH and Eh of a manganese ion containing to-be-processed water is installed in the promotion oxidation tank 10. As shown in FIG.

  The second packed column 20 b is a manganese ion recovery device that recovers manganese ions from the manganese ion-containing treated water generated in the promoting oxidation tank 10. The second packed column 20 b is connected to the promoting oxidation tank 10 via a pipe 305. The pipe 305 includes a pump 50b, an oxidant supply pipe 40b, and a pH adjuster supply pipe 41b. The pipe 305 further has a pipe 306 connected via the three-way valves 60d and 60e. The pipe 306 is a bypass when the pump 50b is not used.

  The second packed column 20b is packed with manganese adsorbent particles 201b. The shape of the manganese adsorbent particles 201b is not particularly limited as long as there is no hindrance to water flow, but particles having an average particle diameter in the range of 0.1 to 5 mm are preferable. The manganese adsorbent particle 201b may be a particle of a compound different from the manganese compound particle 201a, but is preferably a particle of the same compound. The water flow direction of the second packed tower 20b is not particularly limited, and may be either upward or downward. Also, the water flow direction may be a lateral direction. The second packed column 20b includes a sensor (not shown) that measures pH and Eh.

The second packed tower 20 b is connected to a raw water storage tank (not shown) via a pipe 307. The pipe 307 includes a pump 50 d, a three-way valve 60 f, an ozone supply pipe 40 c, and a pH adjuster supply pipe 41 c. A pipe 308 branches from the three-way valve 60f, and the pipe 308 is connected to a treatment water tank (not shown).
The treated water tank is a tank for temporarily storing treated water after recovering manganese ions from the manganese ion-containing treated water, and thereafter releasing the treated water to the outside.

  The controller 102 operates the pumps 50a, 50b, 50c, 50d and the three-way valves 60a, 60b, 60c, 60d, 60e, 60f to carry out the water treatment by the water treatment system 1. In addition, the controller 102 controls the acceleration oxidation tank 10 based on the pH value and the Eh value measured by the sensor 103 of the acceleration oxidation tank 10 and the sensors (not shown) of the first packed column 20a and the second packed column 20b. The feed rates of the pH adjuster and the ozone are adjusted so that the water in the first packed column 20a and the second packed column 20b is maintained at an appropriate pH value and Eh value.

Hereinafter, a water treatment method using the water treatment system 1 will be described.
First, the pump 50 a is operated to feed raw water stored in a raw water storage tank (not shown) into the first packed tower 20 a through the pipe 301. At this time, ozone is supplied from the ozone supply pipe 40a so that the pH value (X) and the Eh value (Y) of the raw water satisfy the above-mentioned equation (that is, within the range of (I) in FIG. 2). The pH adjuster is supplied from the pH adjuster supply pipe 41a. The raw water thus adjusted in pH value (X) and Eh value (Y) is charged into the first packed tower 20a, and the raw water is brought into contact with the manganese compound particles 201a to supply manganese ions to the raw water. A manganese ion containing to-be-processed liquid is prepared by carrying out.

  Next, the three-way valves 60b and 60c are operated, and the manganese ion-containing to-be-treated liquid prepared in the first packed column 20a is introduced into the promoting oxidation tank 10 through the pipe 304.

  Next, while the manganese ion-containing treated water is stirred by the stirrer 101 in the promoting oxidation tank 10, the pH value (X) and the Eh value (Y) of the manganese ion-containing treated water satisfy the above equation (That is, in the region of (II) in FIG. 2), ozone is supplied from the ozone supply pipe 104, and a pH adjuster is supplied from the pH adjuster supply pipe 105. Thus, by adjusting the pH value (X) and the Eh value (Y) of the manganese ion-containing treated water in the promoting oxidation tank 10, the organic matter is removed by the accelerated oxidation, and the manganese ion-containing treated water Generates.

  Next, the pump 50b and the three-way valves 60d and 60e are operated, and the manganese ion-containing treated water generated in the promotion oxidation tank 10 is introduced into the second packed tower 20b through the pipe 305. At this time, the oxidizing agent is used so that the pH value (X) and the Eh value (Y) of the manganese ion-containing treated water satisfy the above equation (that is, within the range of (III) in FIG. 2). Ozone or hypochlorous acid is supplied from the supply pipe 40b, and a pH adjuster is supplied from the pH adjuster supply pipe 41b. The manganese ion-containing treated water whose pH value (X) and Eh value (Y) have been adjusted in this manner is charged into the second packed column 20b to bring the manganese ion-containing treated water into contact with the manganese adsorbent particles 201b. The manganese ion is recovered by adsorbing the manganese ion to the manganese adsorbent particle 201b. The manganese ion-containing treated water may be continuously introduced into the second packed column 20b or may be subjected to accelerated oxidation until the organic matter is sufficiently removed in the accelerated oxidation tank 10. May be

  Next, the three-way valve 60 f is operated, and the treated water from which manganese ions have been collected is introduced into the treated water tank (not shown) through the pipe 308.

  When the above water treatment is performed, the manganese in the manganese compound particles 201a of the first packed column 20a is gradually moved to the manganese adsorbent particles 201b of the second packed column 20b. Therefore, in the water treatment system 1, the treatment can also be performed by flowing the raw water from the second packed tower 20b side. That is, after the water treatment system 1 performs the water treatment for a certain period of time, the raw water stored in the raw water storage tank is charged into the second packed tower 20b, and the manganese adsorbent which adsorbs the raw water and manganese ions The particles 201 b are brought into contact, and manganese ion-containing treated water is prepared by supplying manganese ions to the raw water, and then the manganese ion-containing treated water is introduced into the promoting oxidation tank 10, and the organic substance is produced in the promoting oxidation tank 10. Is removed by accelerated oxidation to form manganese ion-containing treated water, and the manganese ion-containing treated water is introduced into the first packed column 20a to bring the manganese ion-containing treated water into contact with the manganese compound particles 201a to produce manganese. The compound particle 201a is made to be able to adsorb manganese ions. By doing this, since manganese moves from the manganese adsorbent particle 201b to the manganese compound particle 201a, it is possible not only to maintain the balance of manganese in the system, but also to add water from the outside without adding a manganese compound from the outside. Processing can be performed.

Hereinafter, although the same description is omitted, a water treatment method in the case of flowing raw water from the second packed tower 20b side will be described.
First, the pump 50d and the three-way valve 60f are operated to feed raw water stored in a raw water storage tank (not shown) through the pipe 307 into the second packed tower 20b. At this time, the ozone is supplied from the ozone supply pipe 40c so that the pH value (X) and the Eh value (Y) of the raw water satisfy the above equation (that is, within the range of (I) in FIG. 2). The pH regulator is supplied from the pH regulator supply pipe 41c. The raw water whose pH value (X) and Eh value (Y) are adjusted in this manner is charged into the second packed column 20b, and the raw water is brought into contact with the manganese adsorbent particles 201b adsorbing manganese ions. The manganese ion-containing liquid to be treated is prepared by supplying manganese ions to the raw water.

  Next, the three-way valves 60d and 60e are operated, and the manganese ion-containing to-be-treated liquid prepared in the second packed column 20b is introduced into the promoting oxidation tank 10 through the pipe 306.

  Next, in the accelerated oxidation tank 10, the organic matter is removed by accelerated oxidation to generate manganese ion-containing treated water. The conditions for removing the organic matter by oxidation promotion are the same as those described above.

  Next, the pump 50 c and the three-way valves 60 b and 60 c are operated, and the manganese ion-containing treated water generated in the promotion oxidation tank 10 is introduced into the first packed tower 20 a through the pipe 303. At this time, the oxidizing agent is used so that the pH value (X) and the Eh value (Y) of the manganese ion-containing treated water satisfy the above equation (that is, within the range of (III) in FIG. 2). Ozone or hypochlorous acid is supplied from a supply pipe 40d, and a pH adjuster is supplied from a pH adjuster supply pipe 41d. The manganese ion-containing treated water whose pH value (X) and Eh value (Y) have been adjusted in this manner is introduced into the second packed column 20b to bring the manganese ion-containing treated water into contact with the manganese compound particles 201a. The manganese ion is recovered by adsorbing the manganese ion to the manganese compound particle 201a.

  Next, the three-way valve 60 a is operated, and the treated water from which manganese ions have been collected is introduced into the treated water tank (not shown) through the pipe 302.

  In the water treatment system 1 according to the first embodiment described above, the raw water containing an organic substance is a manganese ion-containing treated water containing a predetermined amount of manganese ion, and the pH value (X) and the Eh value (Y) Since adjustment is made to satisfy a predetermined formula, organic substances in the manganese ion-containing treated water can be efficiently removed by accelerated oxidation. In addition, since raw water can be flowed from either the first packed column 20a side or the second packed column 20b side, water treatment can be continuously performed without adding a manganese compound from the outside.

Second Embodiment
FIG. 6 is a schematic view of a water treatment system according to a second embodiment.
In addition, in the following description, the same number is attached | subjected to the structure similar to the water treatment system 1 of 1st Embodiment, and the overlapping description is abbreviate | omitted.

  In the water treatment system 2 of the second embodiment shown in FIG. 6, a raw water storage tank (not shown) and the promoting oxidation tank 10 are connected via a pipe 309. The pipe 309 comprises a pump 50 e and a manganese solution supply pipe 42. The water treatment system 2 is different from the water treatment system 1 in that a manganese solution is used to supply manganese ions to the raw water. The manganese solution is not particularly limited as long as it contains manganese as an ion. Manganese nitrate solution etc. are mentioned as an example of manganese solution.

The water treatment method using the water treatment system 2 of the second embodiment will be described below.
First, the pump 50 e is operated to feed raw water stored in a raw water storage tank (not shown) into the promoting oxidation tank 10 through the pipe 309. At this time, the manganese solution supplied from the manganese solution supply pipe 42 and the raw water are mixed, and the raw water is introduced into the promoting oxidation tank 10 as a manganese ion-containing liquid to be treated.

  Next, in the promoting oxidation tank 10, the organic matter in the manganese ion-containing treated water is removed by oxidation promotion to generate a manganese ion-containing treated water. The method of removing the organic matter by oxidation promotion can be the same as in the case of the water treatment system 1.

  Next, the pump 50b is operated, and the manganese ion-containing treated water generated in the promoting oxidation tank 10 is introduced into the second packed column 20b through the pipe 305, and the manganese ion-containing treated water and the manganese adsorbent particles 201b are The manganese ion is recovered by adsorbing the manganese ion to the manganese adsorbent particle 201b in contact with the catalyst. In the water treatment system 2, when the water treatment is continued, manganese is accumulated in the manganese adsorbent particles 201b. Therefore, the manganese adsorbent particles 201b need to be replaced after performing a certain treatment.

  The water treatment system 2 of the second embodiment described above uses a manganese solution to supply manganese ions to the raw water, so a fixed amount of manganese ions can be added to the raw water regardless of the water quality (pH, Eh) of the raw water. Can be supplied stably.

Third Embodiment
FIG. 7 is a schematic view of a water treatment system according to a third embodiment.
In addition, in the following description, the same number is attached | subjected to the structure similar to the water treatment system 2 of 2nd Embodiment, and the overlapping description is abbreviate | omitted.

  The water treatment system 3 of the third embodiment shown in FIG. 7 differs from the water treatment system 2 in that the ion exchange resin 202 is filled as manganese adsorbent particles in the second packed column 20b. The second packed column 20b is provided with a regenerated liquid supply pipe 310 for supplying a regenerated liquid of ion exchange resin, and a regenerated liquid discharge pipe 311 for discharging the regenerated liquid from the second packed tower 20b. As the regenerating solution, an acid such as hydrochloric acid can be used.

The water treatment method using the water treatment system 3 of the third embodiment will be described below.
Raw water and a manganese solution are mixed in a pipe 309, and the raw water is introduced into the promoting oxidation tank 10 as a manganese ion-containing liquid to be treated. Next, in the promoting oxidation tank 10, the organic matter in the manganese ion-containing treated water is removed by oxidation promotion to generate a manganese ion-containing treated water. Next, the manganese ion-containing treated water is introduced into the second packed column 20b, and manganese ions in the manganese ion-containing treated water are recovered in the second packed column 20b. These operations can be the same as the water treatment system 2 of the second embodiment.

  In the water treatment system 3 of the third embodiment, manganese ions in the manganese ion-containing treated water are recovered by being adsorbed to the ion exchange resin 202. It is necessary to recover the manganese ion from the ion exchange resin 202 to regenerate the adsorption capacity after performing a certain treatment so that the manganese ion adsorption capacity of the ion exchange resin 202 does not decrease. Therefore, it is necessary to periodically charge the second packed column 20b with the regenerating solution from the regenerating solution supply pipe 310 and take out the regenerating solution from which the manganese ions are recovered from the ion exchange resin 202 from the regenerating solution discharge pipe 311. .

  According to the water treatment system 3 of the third embodiment described above, since the ion exchange resin is used as the manganese adsorbent particles, manganese ion can be used over a long period of time by repeatedly regenerating and using this ion exchange resin. It can be recovered stably.

  According to at least one embodiment described above, manganese ions are supplied to raw water containing organic matter to prepare manganese ion-containing treated water having a manganese ion concentration of 0.01 mg / L to 10 mg / L. And X, which is the pH value of the manganese ion-containing treated water, and Y (unit: V), which is the redox potential value measured using a standard hydrogen electrode as a comparison electrode, satisfy a predetermined equation As described above, a step of supplying a pH adjuster and ozone to the manganese ion-containing treated water to remove organic substances in the manganese ion-containing treated water by accelerated oxidation to generate a manganese ion-containing treated water; By removing and having manganese ions in the ion-containing treated water, organic matter in the water is efficiently removed by accelerated oxidation. It is possible.

Hereinafter, embodiments will be described in detail using examples.
Example 1
The water treatment system 2 according to the second embodiment shown in FIG. 6 was used to examine the manganese ion concentration in the accelerated oxidation tank 10 and the catalytic effect on the accelerated oxidation.
Raw water containing phenol at a concentration of 100 mg / l was charged into the raw water storage tank. Next, the pump 50 e was operated to feed the raw water stored in the raw water storage tank into the promoting oxidation tank 10 through the pipe 309. At this time, an aqueous solution of manganese nitrate is supplied to the raw water from the manganese solution supply pipe 42, the aqueous solution of manganese nitrate and the raw water are mixed, and the raw water is treated with manganese ions containing 0.001 to 10 mg / l of manganese ion It was a liquid.
Phosphoric acid and potassium dihydrogen phosphate are supplied as a pH adjuster from the pH adjuster supply pipe 105 while stirring the manganese ion-containing liquid to be treated in the promoting oxidation tank 10 using the stirrer 101 to obtain manganese. The pH value (X) of the ion-containing liquid to be treated was adjusted to be in the range of 3.2 to 3.5. Further, an ozone containing gas having an ozone concentration of 200 g / m ³ was supplied from the ozone supply pipe 104 to adjust the Eh value (Y) of the manganese ion containing liquid to be 1.0 to 1.1 V. In addition, the Eh value of the manganese ion containing to-be-processed liquid was computed using the following conversion formula from the oxidation reduction potential measured using the silver chloride electrode as a comparison electrode.

(Conversion equation)
Eh = E _{Ag / AgCl} + {206-0.7 (t-25)} / 1000
Eh: Redox potential (V) when using a standard hydrogen electrode as a reference electrode
E _{Ag / AgCl} : Redox potential (V) when using a silver chloride electrode as a reference electrode
t: Temperature [° C]

The manganese ion-containing liquid to be treated was treated for 60 minutes in the promoting oxidation tank 10 to produce a manganese ion-containing liquid to be treated.
Next, the pump 50b and the three-way valves 60d and 60e were operated to charge the manganese ion-containing treatment liquid in the accelerated oxidation tank 10 into the second packed column 20b. In the second packed column 20b, filtration sand in which manganese dioxide was coated on the surface with an average particle diameter of about 1 mm was packed as manganese adsorbent particles 201b. At this time, hypochlorous acid is introduced from the oxidizing agent supply pipe 40b, and sodium hydroxide is added to the manganese ion-containing treatment liquid from the pH adjuster supply pipe 41b, and the pH value (X) of the manganese ion-containing treatment liquid is obtained. 7.2, Eh value (Y) was adjusted to 0.8V.

  The treated water taken out of the second packed column 20 b through the pipe 307 had a manganese ion concentration of 0.1 mg / l or less.

(Evaluation)
The catalytic effect on accelerated oxidation was evaluated from the organic matter decomposition rate calculated from the following equation using TOC (Total Organic Carbon: total organic carbon). The TOC was measured using a Shimadzu TOC TOC meter TOC-L.
Organic matter decomposition rate (%) = (TOC of raw water-TOC of treated water) / TOC of raw water × 100

  The relationship between the manganese ion concentration of the manganese ion-containing treated water in the accelerated oxidation tank 10 and the organic substance decomposition rate is shown in FIG. From the graph in FIG. 8, the organic substance removal rate was about 60% when the manganese ion concentration was 0.001 mg / l, but the organic matter decomposition rate was in the range of 0.01 to 10 mg / l. It exceeded 80%, and it turned out that the catalytic effect of manganese ion becomes high. In particular, when the manganese ion concentration was in the range of 0.05 to 0.2 mg / l, the organic substance removal rate exceeded 95%, and it was found that the catalytic effect of the manganese ion was very high.

Comparative Example 1
The phenol decomposition test was carried out under the same conditions as the manganese ion concentration of 2 mg / l in Example 1 except that the pH value (X) of the manganese ion-containing treated water in the accelerated oxidation tank 10 was changed to 7, 60 minutes The organic matter decomposition rate after that was 55%, and there was almost no catalytic effect of manganese ion.

Example 2
Using the water treatment system 1 of the first embodiment shown in FIG. 5, raw water containing phenol at a concentration of 100 mg / l was treated. The first packed tower 20a and the second packed tower 20b were each packed with filtration sand in which manganese dioxide was coated on the surface having an average particle diameter of about 1 mm used in Example 1.
Raw water with a pH value (X) adjusted to 3.0 to 3.6 and an Eh value (Y) adjusted to 1.2 to 1.3 is supplied to the first packed column 20a, and manganese ion-containing treated water Was prepared. The manganese ion-containing treated water obtained had a manganese ion concentration of 0.5 to 2 mg / l.
The Eh value (Y) of the manganese ion-containing treated water was adjusted to 1.0 to 1.1 in the accelerated oxidation tank 10, and the organic substance removal rate after 60 minutes was 80% or more.

[Example 3]
A test was conducted in the same manner as in Example 2 except that manganese ferrite having an average particle diameter of about 500 μm was used as the manganese compound particle 201 a. As a result, manganese ion containing 0.01 to 0.19 mg / l of manganese ion was contained. Water to be treated was obtained. When the Eh value (Y) of the manganese ion-containing treated water was adjusted to 1.0 to 1.1 V in the promoting oxidation tank 10, the organic substance removal rate after 60 minutes was 80% or more .

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

1, 2, 3 Water treatment system 10 Accelerated oxidation tank 20a First packed column (manganese ion supply device) 20b Second packed column (manganese ion recovery device) 40a 40c Ozone supply pipe 40b, 40d: oxidant supply pipe, 41a, 41b, 41c, 41d ... pH adjuster supply pipe, 50a, 50b, 50c, 50d ... pump, 60a, 60b, 60c, 60d, 60e, 60f, three-way valve, 103 ... Sensor, 201a ... manganese compound particle, 201b ... manganese adsorbent particle, 301, 302, 303, 304, 305, 306, 307, 308, 309 ... piping, 310 ... regenerating liquid supply pipe, 311 ... regenerating liquid discharge pipe

Claims (8)

A water treatment method for removing organic matter in raw water containing organic matter by accelerated oxidation, comprising:
Supplying manganese ions to the raw water to prepare manganese ion-containing treated water having a manganese ion concentration of 0.01 mg / L or more and 10 mg / L or less;
The above X is a pH value of the manganese ion-containing treated water, and Y (unit: V) a redox potential value measured using a standard hydrogen electrode as a comparison electrode satisfies the following equation. Supplying a pH adjuster and ozone to the manganese ion-containing treated water to remove the organic matter in the manganese ion-containing treated water by accelerated oxidation to generate a manganese ion-containing treated water;
2 ≦ X ≦ 5
0.8 ≦ Y ≦ 1.5-0.08 × X
Recovering manganese ions in the manganese ion-containing treated water;
Water treatment method having. In the step of preparing the manganese ion-containing treated water, a pH adjuster and ozone are supplied to the raw water, and X which is the pH value of the raw water and the redox potential measured using a standard hydrogen electrode as a comparison electrode The method is performed by adjusting the value Y (unit: V) to satisfy the following formula, bringing the raw water into contact with the manganese compound particles, and supplying manganese ions to the raw water. Water treatment method described.
2 ≦ X ≦ 5
1.5-0.08 × X <Y In the step of recovering manganese ions in the manganese ion-containing treated water, a pH adjuster and ozone or hypochlorous acid are supplied to the manganese ion-containing treated water to obtain a pH value of the manganese ion-containing treated water X And the redox potential value Y (unit: V) measured using a standard hydrogen electrode as a reference electrode so as to satisfy the following equation, the manganese ion-containing treated water and manganese adsorbent particles The water treatment method according to claim 1, wherein the manganese adsorbent particles are made to adsorb manganese ions by bringing the manganese adsorbent particles into contact with each other.
5 <X ≦ 9
0.6 ≦ Y ≦ 1.5-0.08 × X In the step of preparing the manganese ion-containing treated water, the raw water is introduced into the first packed tower using the first packed tower filled with manganese compound particles, and the raw water and the manganese compound particles are mixed. The step of contacting is performed by supplying manganese ions to the raw water, and the step of recovering manganese ions in the manganese ion-containing treated water is performed using the second packed tower filled with manganese adsorbent particles, the manganese ions Containing treated water is introduced into the second packing tower, the treated water containing manganese ions is brought into contact with the manganese adsorbent particles, and manganese ions are adsorbed to the manganese adsorbent particles,
Thereafter, in the step of preparing the manganese ion-containing treated water, the raw water is introduced into the second packed tower, and the raw water is brought into contact with the manganese adsorbent particles having the manganese ion adsorbed thereon, to obtain the raw water The step of collecting manganese ions in the manganese ion-containing treated water is carried out by supplying manganese ions to the first, and the manganese ion-containing treated water is introduced into the first packed column to carry out the step The water treatment method according to claim 1, which is performed by bringing compound particles into contact with each other to cause the manganese compound particles to adsorb manganese ions. A water treatment apparatus for removing organic matter in raw water containing organic matter by accelerated oxidation, comprising:
Raw water storage tank which stores raw water containing organic matter,
A manganese ion supply device for supplying manganese ions to the raw water to prepare a manganese ion-containing treated water having a manganese ion concentration in the range of 0.01 mg / L to 10 mg / L ;
The above X is a pH value of the manganese ion-containing treated water, and Y (unit: V) a redox potential value measured using a standard hydrogen electrode as a comparison electrode satisfies the following equation. An accelerating oxidation tank for supplying manganese ion-containing treated water with a pH adjuster and ozone to remove the organic matter in the manganese ion-containing treated water by accelerated oxidation to generate manganese ion-containing treated water;
2 ≦ X ≦ 5
0.8 ≦ Y ≦ 1.5-0.08 × X
And a manganese ion recovery device for recovering manganese ions from the manganese ion-containing treated water. A water treatment system for removing organic matter in raw water containing organic matter by accelerated oxidation, comprising:
Raw water storage tank which stores raw water containing organic matter,
A manganese ion supply device for supplying manganese ions to the raw water to prepare a manganese ion-containing treated water having a manganese ion concentration in the range of 0.01 mg / L to 10 mg / L ;
The above X is a pH value of the manganese ion-containing treated water, and Y (unit: V) a redox potential value measured using a standard hydrogen electrode as a comparison electrode satisfies the following equation. An accelerating oxidation tank for supplying manganese ion-containing treated water with a pH adjuster and ozone to remove the organic matter in the manganese ion-containing treated water by accelerated oxidation to generate manganese ion-containing treated water;
2 ≦ X ≦ 5
0.8 ≦ Y ≦ 1.5-0.08 × X
A manganese ion recovery device for recovering manganese ions from the manganese ion-containing treated water;
And a controller.
Wherein the control device, the said raw water reserved in the raw water storage tank was charged into the manganese ion supply device, manganese ion-containing water to be treated by supplying the manganese ions in the raw water in the manganese ion supply device was prepared and then the manganese ion-containing water to be treated was put into the accelerated oxidation vessel, to produce a manganese-ion containing treatment water was removed by advanced oxidation of said organic material in said advanced oxidation tank, and then the manganese ions A water treatment system in which contained treated water is introduced into the manganese ion recovery device, and manganese ions are recovered by the manganese ion recovery device. The manganese ion supply device is a first packed tower filled with manganese compound particles,
The manganese ion recovery device is a second packed tower filled with manganese adsorbent particles, wherein
The control device, by introducing the raw water that is stored in the raw water storage tank to the first packed column, wherein contacting the raw water and the manganese compound particles, by supplying manganese ions in the raw water preparing a manganese ion-containing water to be treated, then generate the manganese ion-containing water to be treated was put into the accelerated oxidation vessel, the manganese ion containing process water is removed by promoting oxidation of the organic material in the accelerated oxidation vessel And then the manganese ion-containing treated water is introduced into the second packed column to bring the manganese ion-containing treated particle into contact with the manganese ion-containing treated water to cause the manganese adsorbent particles to adsorb manganese ions. Recover manganese ions by
Then, by introducing the raw water that is stored in the raw water storage tank in the second packed column, wherein contacting the raw water with the manganese adsorbent particles manganese ions are adsorbed, the manganese ions in the raw water manganese ion-containing water to be treated was prepared by feeding, then put the manganese ion-containing water to be treated to the advanced oxidation tank, removed to contain manganese ions by promoting oxidation of the organic material in the accelerated oxidation vessel Treated water is generated, and the manganese ion-containing treated water is introduced into the first packed column to bring the manganese ion-containing treated water into contact with the manganese compound particles to cause the manganese compound particles to adsorb manganese ions. The water treatment system according to claim 6, wherein manganese ions are recovered thereby. A water treatment system for removing organic matter in raw water containing organic matter by accelerated oxidation, comprising:
Raw water storage tank which stores raw water containing organic matter,
A manganese ion supply device for supplying manganese ions to the raw water to prepare manganese ion-containing treated water;
An accelerated oxidation tank for removing the organic matter in the manganese ion-containing treated water by accelerated oxidation to generate treated water containing manganese ions;
A manganese ion recovery device for recovering manganese ions from the manganese ion-containing treated water;
And a controller.
The manganese ion supply device is a first packed tower filled with manganese compound particles,
The manganese ion recovery device is a second packed tower filled with manganese adsorbent particles, wherein
The control device inputs the raw water stored in the raw water storage tank into the first packed tower, brings the raw water into contact with the manganese compound particles, and supplies manganese ions to the raw water. A manganese ion-containing treated water is prepared, and then the manganese ion-containing treated water is introduced into the accelerated oxidation tank, and the organic matter is removed by accelerated oxidation in the promoted oxidation tank to produce a manganese ion-containing treated water And then the manganese ion-containing treated water is introduced into the second packed column to bring the manganese ion-containing treated particle into contact with the manganese ion-containing treated water to cause the manganese adsorbent particles to adsorb manganese ions. Recover manganese ions by
Thereafter, the raw water stored in the raw water storage tank is charged into the second packed tower, and the raw water is brought into contact with the manganese adsorbent particles having the manganese ion adsorbed thereon, so that manganese ions are added to the raw water. The manganese ion-containing treated water is prepared by supplying, and then the manganese ion-containing treated water is introduced into the accelerated oxidation tank, and the organic matter is removed by accelerated oxidation in the accelerated oxidation tank to contain manganese ions. Treated water is generated, and the manganese ion-containing treated water is introduced into the first packed column to bring the manganese ion-containing treated water into contact with the manganese compound particles to cause the manganese compound particles to adsorb manganese ions. Water treatment system to recover manganese ions by

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