JP7293841B2 - Neutralization system for effluent flowing through dialysis effluent flow path - Google Patents

Description

The present invention relates to a neutralization system for effluent flowing through a dialysis effluent flow path.

Japanese Patent No. 4249642 (Patent Document 1) is a prior art document that discloses a waste liquid treatment method for an aqueous system of a dialysis facility. In the waste liquid treatment method for the aqueous system of the dialysis facility described in Patent Document 1, the washing waste liquid is neutralized using the dialysis waste liquid.

Patent No. 4249642

In the case of neutralizing the washing effluent using the dialysis effluent, the pH of the dialysis effluent cannot be adjusted, so the pH of the effluent after the neutralization treatment may not be maintained within the set range. If a neutralizing solution containing components different from the dialysate is separately prepared for neutralizing the washing waste fluid, the structure of the neutralization system becomes complicated.

The present invention has been made in view of the above problems, and is capable of maintaining the pH of the neutralized effluent within a set range with a simple configuration. To provide a neutralization system for

A system for neutralizing effluent flowing through a dialysis effluent channel according to the present invention includes a dialysis effluent channel, a cleaning liquid supply section, a liquid storage section, a stock solution injection section, a mixing section, and a control section. . The dialysate effluent flow path is connected to the dialyzer and carries the effluent. The cleaning liquid supply unit is connected to the dialysate flow path through which the dialysate flows, and supplies the cleaning liquid for cleaning the dialysate flow path. A part of the solute component of the dialysate is dissolved in the liquid storage part, so that the undiluted liquid having a liquid property opposite to that of the washing liquid is stored. The stock solution injection part is connected to the dialysis drainage channel, and injects the stock solution from the storage part into the dialysis drainage channel. The mixing section is positioned downstream of the connecting position with the stock solution injection section in the dialysis drainage flow path, and mixes the washing liquid and the stock solution. The control section is electrically connected to each of the cleaning liquid supply section and the undiluted solution injection section. The control unit determines the concentration and flow rate of the undiluted solution to be injected from the undiluted solution injection unit into the dialysis drainage channel according to the pH and flow rate of the cleansing solution supplied from the cleansing solution supply unit, and controls the flow rate of the cleansing solution from the cleansing solution supply unit. After the supply is started, the undiluted liquid is injected from the undiluted liquid injection unit into the dialysis drainage channel according to the preset neutralization start condition.

In one aspect of the present invention, the cleaning liquid supply section is configured to selectively supply cleaning liquids having different liquid properties. The concentrate injection part is configured to be capable of selectively injecting a first concentrate and a second concentrate having different properties as concentrates into the dialysis drainage channel. The control unit causes the one of the first undiluted solution and the second undiluted solution to be injected from the undiluted fluid injection unit into the dialysis drainage channel, which has a liquid property different from that of the cleaning fluid.

In one aspect of the present invention, a first measuring unit for measuring the pH of the waste fluid is provided at a position upstream of the undiluted solution injection position, which is a connection position with the undiluted solution injection unit in the dialysis drainage flow channel. The control unit receives the measurement result from the first measurement unit.

In one aspect of the present invention, a second measuring section for measuring the pH of the effluent is provided at a position downstream of the mixing section in the dialysis effluent channel. The control unit receives the measurement result from the second measurement unit.

In one aspect of the present invention, the control unit causes the cleaning liquid supplied from the cleaning liquid injection position, which is the connection position with the cleaning liquid supply section in the dialysate flow path, to flow into the dialysate drainage flow after the cleaning liquid supply section starts supplying the cleaning liquid. After the time required for the raw solution to reach the raw solution injection position, which is the connection position with the raw solution injection part in the channel, the raw solution is injected from the raw solution injection part into the dialysis drainage channel.

In one aspect of the present invention, the control unit causes the undiluted solution injection unit to inject the undiluted solution into the dialysis drainage channel from the time when the pH of the effluent measured by the first measurement unit exceeds the first set range.

In one aspect of the present invention, the control unit controls the flow rate of the undiluted solution from the undiluted solution injection unit from the time when the pH of the waste liquid measured by the first measurement unit exceeds the second set range including the first set range. to increase

In one aspect of the present invention, the control unit causes the pH of the drainage measured by the first measurement unit to increase to the second pH from the time when the pH of the drainage measured by the first measurement unit exceeds the second set range. The flow rate of the stock solution from the stock solution injection part is increased in proportion to the value exceeding the set range.

In one aspect of the present invention, the control unit increases the flow rate of the undiluted solution from the undiluted solution injection unit when the pH of the waste liquid measured by the second measurement unit exceeds the third set range.

In one aspect of the present invention, the control unit sets the pH of the drainage measured by the second measurement unit to the third set range from the time when the pH of the drainage measured by the second measurement unit exceeds the third set range. The flow rate of the stock solution from the stock solution injection part is increased in proportion to the value exceeding the set range.

ADVANTAGE OF THE INVENTION According to this invention, pH of the waste liquid after a neutralization process can be maintained in a setting range with a simple structure.

1 is a system diagram showing the configuration of a system for neutralizing waste fluid flowing through a dialysis waste fluid channel according to Embodiment 1 of the present invention. FIG. FIG. 2 is a block diagram showing the configuration of a control unit included in the system for neutralizing the drainage fluid flowing through the dialysis drainage fluid channel according to the first embodiment of the present invention; FIG. 10 is a system diagram showing the configuration of a system for neutralizing waste fluid flowing through a dialysis waste fluid channel according to Embodiment 2 of the present invention.

Hereinafter, a system for neutralizing waste fluid flowing through a dialysis waste fluid channel according to each embodiment of the present invention will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a system diagram showing the configuration of a system for neutralizing waste fluid flowing through a dialysis waste fluid channel according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing the configuration of a control unit included in the neutralization system for the drainage fluid flowing through the dialysis drainage channel according to the first embodiment of the present invention.

As shown in FIGS. 1 and 2, a system 100 for neutralizing waste fluid flowing through a dialysis waste fluid channel according to Embodiment 1 of the present invention includes a dialysis waste fluid channel 120, a cleaning fluid supply unit 130, and a reservoir. , an undiluted solution injection unit 180 , a mixing unit 123 , and a control unit 10 .

As shown in FIG. 1, the dialysis effluent flow path 120 is connected to the dialyzer 110 through which effluent flows. The waste liquid includes a dialysate waste liquid that is a used dialysate and a washing liquid that is a washing liquid after washing the dialysate flow path 171 .

The cleaning liquid supply unit 130 is connected to the dialysate flow path 171 through which the dialysate flows, and supplies the cleaning liquid for cleaning the dialysate flow path 171 . Specifically, the cleaning liquid supply unit 130 is connected to the cleaning liquid injection position 172 of the dialysate flow path 171 . Note that the cleaning liquid supply unit 130 may be provided in a dialysate preparation device 170 or a dialyzer 110, which will be described later.

In this embodiment, the cleaning liquid supply unit 130 is configured to selectively supply cleaning liquids having different liquid properties. Specifically, the cleaning liquid supply unit 130 is configured to selectively supply cleaning liquids used for acid cleaning and alkaline cleaning. Note that the cleaning liquid supply unit 130 may be configured to be capable of supplying only one of the cleaning liquids used for acid cleaning and alkali cleaning.

The cleaning liquid used for acid cleaning includes, for example, an acetic acid aqueous solution, a peracetic acid aqueous solution, or a citric acid aqueous solution having a concentration of 0.5% or more and 2.0% or less. A cleaning liquid used for alkaline cleaning is, for example, a sodium hypochlorite aqueous solution having a concentration of 100 mg/L or more and 1000 mg/L or less.

The cleaning liquid supply unit 130 incorporates an acid tank for storing the acid cleaning liquid, an alkali tank for storing the alkaline cleaning liquid, and a pump for selectively feeding the cleaning liquid from either the acid tank or the alkaline tank.

A part of the solute component of the dialysate is dissolved in the liquid storage part, so that the undiluted liquid having a liquid property opposite to that of the washing liquid is stored. In this embodiment, a first liquid storage section 141 and a second liquid storage section 151 are provided as liquid storage sections.

As the stock solution, a first stock solution and a second stock solution are generated. The first stock solution is a part of the solute component of the dialysate, for example, a first powder containing at least one of calcium salt, magnesium salt, potassium salt and sodium salt, and glucose is dissolved in water. It is a liquid formulation. The second concentrate is a liquid formulation prepared by dissolving in water a second powder containing at least sodium bicarbonate, which is another part of the solute component of the dialysate. A first liquid is produced in the first powder dissolving device 140 . A second stock solution is produced in the second powder dissolving device 150 .

The first liquid storage part 141 is connected to the first powder dissolving device 140 . The first powder dissolving device 140 incorporates a first tank that stores the first concentrate and a first pump that delivers the first concentrate from the first tank. The first powder dissolving device 140 is configured to be able to generate the first stock solution at a desired concentration.

The second liquid storage part 151 is connected to the second powder dissolving device 150 . The second powder dissolving device 150 incorporates a second tank that stores the second concentrate and a second pump that delivers the second concentrate from the second tank. The second powder dissolving device 150 is configured to be able to generate the second concentrate at a desired concentration.

The first powder dissolving device 140 is connected to the dialysate preparation device 170 via the first on-off valve 182 . The second powder dissolving device 150 is connected to the dialysate preparation device 170 via the second on-off valve 184 . The dialysate preparation device 170 is connected to the reverse osmosis water generator 160 .

In the dialysate preparation device 170, the reverse osmosis water supplied from the reverse osmosis water generator 160, the first undiluted solution supplied from the first powder dissolving device 140, and the second undiluted solution supplied from the second powder dissolving device 150 are mixed to prepare a dialysate. The dialysate preparation device 170 is connected to the dialyzer 110 through a dialysate flow path 171 .

The stock solution injection section 180 is connected to the dialysis drainage channel 120 and injects the stock solution from the storage section into the dialysis drainage channel 120 . Specifically, the undiluted solution injection part 180 includes a third on-off valve 183 provided between the first liquid storage part 141 and the dialysis drainage channel 120, the second liquid storage part 151 and the dialysis drainage channel 120. and a fourth on-off valve 185 provided between and the pump 181 .

Pump 181 is, for example, a gear pump or a metering pump. In the present embodiment, the undiluted solution is injected into the dialysis drainage channel 120 by one pump 181 from each of the first liquid storage section 141 and the second liquid storage section 151. Two pumps may be provided so as to correspond to the two liquid reservoirs 151 on a one-to-one basis.

The first liquid storage part 141 is connected to the dialysis drainage channel 120 via the third on-off valve 183 and the pump 181 . The second liquid storage part 151 is connected to the dialysis drainage channel 120 via the fourth on-off valve 185 and the pump 181 . The stock solution injection part 180 is connected to the stock solution injection position 122 of the dialysis drainage channel 120 . In this manner, the undiluted liquid injection unit 180 is configured to selectively inject the first undiluted liquid and the second undiluted liquid having different properties as the undiluted liquids into the dialysis drainage channel 120 .

The mixing section 123 is located downstream from the raw solution injection position 122, which is the connection position with the raw solution injection section 180, in the dialysis drainage channel 120, and mixes the washing liquid and the raw liquid. In this embodiment, the mixing section 123 is a portion where the dialysis drainage channel 120 is bent in a U shape.

A gas separation section 124 is provided on the downstream side of the mixing section 123 in the dialysis drainage flow path 120 to separate the gas generated by the neutralization reaction of the drainage from the drainage. An exhaust fan 194 for discharging gas is attached to the gas separation section 124 . Instead of the exhaust fan 194, the gas separation section 124 may be provided with a vent that releases gas when the internal pressure of the gas separation section 124 exceeds a threshold value.

A buffer section 125 is provided downstream of the gas separation section 124 in the dialysis drainage channel 120 . Limestone 193 is accommodated in the buffer portion 125 . Limestone 193 reacts with acid to form carbonate, with carbon dioxide to form calcium oxide, and with alkali to form calcium hydroxide.

A mesh 126 for preventing outflow of limestone 193 is arranged at the outlet of the buffer section 125 . The outlet of the buffer section 125 is connected with an eccentric socket that is eccentric upwardly and is configured to allow limestone 193 to be deposited on the bottom of the buffer section 125 . Note that the buffer unit 125 may not necessarily be provided.

The effluent discharged from the end 129 of the dialysis effluent channel 120 is flushed to the sewer. Drainage discharged into the sewage system must meet the discharge standards from the viewpoint of environmental load. In the effluent standard, the pH of the effluent must be, for example, 5.8 or more and 8.6 or less.

In the present embodiment, a first pH sensor, which is a first measurement unit for measuring the pH of the waste fluid, is installed at a position upstream of the undiluted solution injection position 122, which is a connection position with the undiluted solution injection unit 180, in the dialysis drainage channel 120. 191 are provided. First pH sensor 191 measures the pH of the effluent at first measurement location 127 of dialysis effluent channel 120 . Note that the first pH sensor 191 may not be provided when the flow rate of the cleaning fluid during cleaning of the dialysate flow path 171 is constant.

A second pH sensor 192 , which is a second measuring section for measuring the pH of the effluent, is provided at a position downstream of the mixing section 123 in the dialysis effluent flow path 120 . A second pH sensor 192 measures the pH of the effluent at the second measurement location 128 of the dialysis effluent flow path 120 .

As shown in FIG. 2, the control unit 10 is electrically connected to each of the cleaning liquid supply unit 130 and the undiluted solution injection unit 180 . Control unit 10 is also electrically connected to each of first pH sensor 191 and second pH sensor 192 . The control unit 10 receives the measurement result from the first pH sensor 191 . The control unit 10 receives the measurement result from the second pH sensor 192 . The control unit 10 includes a storage unit 11 and a computing unit 12 .

Hereinafter, the operation of the system 100 for neutralizing the drainage flowing through the dialysis drainage channel 120 according to the first embodiment of the present invention will be described.

After the dialysis treatment by the dialyzer 110 is completed, the cleaning liquid is supplied from the cleaning liquid supply unit 130 to the dialysate flow path 171 . During the dialysis treatment by the dialysis machine 110, each of the first on-off valve 182 and the second on-off valve 184 is open, and each of the third on-off valve 183 and the fourth on-off valve 185 is closed. When cleaning of the dialysate flow path 171 is started, the controller 10 closes each of the first on-off valve 182 and the second on-off valve 184 and opens each of the third on-off valve 183 and the fourth on-off valve 185 .

In the case of acid cleaning, an acetic acid aqueous solution, a peracetic acid aqueous solution, a citric acid aqueous solution, or the like having a concentration of 0.5% or more and 2.0% or less is supplied from the cleaning liquid supply unit 130 as a cleaning liquid. The pH of this acid cleaning liquid is about 2.6 or more and 3.0 or less. The acid cleaning solution reacts with carbonate and the like adhering to the inside of the dialysate flow path 171 and becomes a cleaning waste solution having a pH of about 2.8 or more and 3.2 or less.

In the case of alkali cleaning, a sodium hypochlorite aqueous solution having a concentration of 100 mg/L or more and 1000 mg/L or less is supplied as a cleaning liquid. The pH of this alkaline cleaning liquid is about 9.0 or more and 10.0 or less. The alkaline cleaning liquid reacts with the protein components and silicon-containing components adhering to the inside of the dialysate flow path 171, and becomes a cleaning waste liquid with a pH closer to neutral than before the reaction.

The control unit 10 causes the undiluted solution injection unit 180 to inject the one of the first undiluted solution and the second undiluted solution that has a liquid property different from that of the washing liquid into the dialysis drainage flow path 120 . Specifically, when the acid cleaning solution is supplied from the cleaning solution supply unit 130 , the control unit 10 causes the second solution injection unit 180 to inject the second solution into the dialysis drainage channel 120 . Conversely, when the alkaline cleaning liquid is supplied from the cleaning liquid supply unit 130 , the control unit 10 causes the raw liquid injection unit 180 to inject the first raw liquid into the dialysis drainage channel 120 .

The control unit 10 determines the concentration and flow rate of the undiluted solution injected from the undiluted solution injection unit 180 into the dialysis drainage channel 120 according to the pH and flow rate of the cleaning solution supplied from the cleaning solution supply unit 130 .

The type of cleaning liquid supplied from the cleaning liquid supply section 130 and the pH or concentration of the cleaning liquid are input in advance and stored in the storage section 11 of the control section 10 . Further, the storage unit 11 of the control unit 10 stores the flow rate of the undiluted solution necessary for neutralizing the cleaning liquid based on the type of cleaning liquid supplied from the cleaning liquid supply section 130, the pH or concentration of the cleaning liquid, and the flow rate of the cleaning liquid. An arithmetic expression for calculation is stored. The control unit 10 stores information stored in the storage unit 11, such as the type of cleaning liquid, the pH or concentration of the cleaning liquid, and an arithmetic expression for calculating the flow rate of the undiluted liquid necessary for neutralizing the cleaning liquid. Based on this, the calculation unit 12 calculates the concentration and flow rate of the undiluted solution to be injected from the undiluted solution injection unit 180 into the dialysis drainage channel 120 .

Here, calculations performed by the calculation unit 12 of the control unit 10 are illustrated.
Weak electrolytes such as acetic acid, peracetic acid, and citric acid have different degrees of divergence depending on the pH of the aqueous solution, so the concentration of the stock solution required for neutralization is calculated from the concentration of the weak electrolyte and the divergence constant.

To calculate the pH of the aqueous solution from the concentration of the weak electrolyte, the mol concentration a is calculated from the concentration and molecular weight of the weak electrolyte, and the degree of divergence α = (exp (ln (0.1 )×pKa)/a) ^1/2 . pH=log(1/aα) is calculated from the mol concentration a and the divergence α.

The concentration of a weak acid at a particular pH is calculated by exp(ln(0.1)*pH)*POWER(0.1,(pH-pKa)).

Since the neutralization reaction is not related to the degree of divergence but depends on the hydrogen ion concentration [H ⁺ ], the alkali equivalent required for neutralization is calculated from the acid equivalent of the cleaning solution minus the desired acid equivalent of the cleaning wastewater after neutralization. can be calculated.

In the following, the case of neutralizing 20 L of acetic acid aqueous solution with a concentration of 1% W/V using sodium hydrogen carbonate with a concentration of 7% W/V will be described in detail.

Acetic acid (CH ₃ COOH) dissociates into H ⁺ and CH ₃ COO ^- in an aqueous solution, and is an acidic weak electrolyte with a dissociation constant (pKa) of 4.76. The molecular weight of acetic acid is about 60. Therefore, the molar concentration of an acetic acid aqueous solution with a concentration of 1% W/V is 0.167 (=10 g/60 g) mol/L.

Sodium bicarbonate (NaHCO ₃ ) dissociates into Na ⁺ and HCO ₃ ^- in an aqueous solution. Sodium bicarbonate is ambidextrous and is a basic weak electrolyte with an acid-side dissociation constant (pKa) of 6.35 and an alkali-side dissociation constant (pKb) of 10.33. The molecular weight of sodium bicarbonate is about 84. The molar concentration of sodium hydrogen carbonate aqueous solution with a concentration of 7% W/V is 0.833 (=70 g/84 g) mol/L.

The neutralization reaction formula of sodium bicarbonate (NaHCO ₃ ) and acetic acid (CH ₃ COOH) is as follows.
_NaHCO3 + _CH3COOH → _CH3COONa + _CO2 + _H2O
Carbon dioxide (CO ₂ ) generated by neutralization is released as carbon dioxide gas, but part of it dissolves in water and becomes H ₂ CO ₃ (H ⁺ +HCO ₃ ⁻ ), and the aqueous solution after neutralization has a density of 1 atm. , in an atmosphere of 25° C., it exhibits a weak acidity of around pH 5.6.

The molarity of the aqueous acetic acid solution with a concentration of 1% W/V is 0.167 mol/L, and since both acetate ions and hydrogen ions are monovalent, the normality of the aqueous acetic acid solution is 0.167 (mol/L)×2. (Eq)=0.333 (Eq/L).

The molarity of the aqueous sodium hydrogen carbonate solution with a concentration of 7% W/V is 0.833 mol/L, and since both Na ⁺ and HCO ₃ ^- are monovalent, the normality of the aqueous sodium hydrogen carbonate solution is 0.833 (mol /L)×2(Eq)=1.67(Eq/L).

The Eq of 20 L of acetic acid is 20 (L) x 0.333 (Eq/L) = 6.67 (Eq). The amount of sodium bicarbonate required for neutralization is 6.67 (Eq)/1.67 (Eq/L) = 4.0 (L).

When acetic acid and sodium bicarbonate are mixed and neutralized, carbon dioxide is produced. Therefore, the dissolved carbon dioxide in the aqueous solution inclines the pH of the aqueous solution to the acidic side, which requires correction.

A volume of 20 L of aqueous acetic acid at a concentration of 1% W/V is neutralized with a volume of 4.0 L of sodium bicarbonate at a concentration of 7% W/V to produce 24.0 L of aqueous solution with a pH of 5.6. be done. The aqueous solution is neutralized by adding sodium bicarbonate at a concentration of 7% W/V until the pH is close to 7.

Since the hydrogen ion concentration of an aqueous solution of pH 5.6 is 2.516×10 ⁻⁶ mol/L, there are 6.0×10 ⁻⁵ mol of hydrogen ions in 24 L of aqueous solution. Therefore, neutralization with 6.0×10 ⁻⁵ mol equivalents of sodium hydrogen carbonate is sufficient, but it is necessary to correct the divergence.

Since the alkaline-side dissociation constant (pKb) of sodium bicarbonate is 10.33, the dissociation degree at around pH 7-8 is about 0.54. Then 6.0×10 ⁻⁵ ÷0.54=1.12×10 ⁻⁴ mol of sodium bicarbonate is required.

Since the molar concentration of the sodium bicarbonate aqueous solution with a concentration of 7% W/V is 0.833 mol/L, 1.12×10 ⁻⁴ (mol)÷0.833 (mol/L)=0.13 (mL ) need to be corrected.

If the pH after neutralization is other than 7, the added aqueous sodium hydrogen carbonate solution will increase the amount of solvent, so correction by increasing the amount of solvent will be necessary. 20 L of an aqueous acetic acid solution (pKa=4.76) at pH 3.0 is neutralized to near pH 5.0 with sodium bicarbonate (pKa=6.31) at a concentration of 7% W/V.

In this case, since all sodium bicarbonate is consumed by the neutralization reaction, it is unnecessary to consider the degree of divergence. The molar concentration of the pH 3.0 aqueous acetic acid solution is 57.545 mmol/L, and the molar concentration of the pH 5.0 aqueous acetic acid solution is 0.00575 mmol/L.

The difference between these molar concentrations is 57.545 (mmol/L)-0.00575 (mmol/L)≈57.539 (mmol/L). The molarity of sodium bicarbonate at a concentration of 7% W/V is 833.23 mmol/L.

Therefore, the required amount X of the aqueous sodium bicarbonate solution satisfies the following equation.
57.539 (mmol/L) x 20 (L) - 833.23 (mmol/L) x X (L) ≈ 0.00575 (mmol/L) x (20 + X) (L)
From the above equation, X≈1.381L. Therefore, in order to neutralize to around pH 5.0, 1.381 L of sodium bicarbonate aqueous solution is required for correction.

Information on the concentration and required amount of the concentrate calculated by the calculation unit 12 as described above is sent to the concentrate injection unit 180 . Based on the information, the concentration of the first concentrate in first reservoir 141, the concentration of the second concentrate in second reservoir 151, and the output of pump 181 are adjusted.

After the supply of the cleaning liquid from the cleaning liquid supply section 130 is started, the control section 10 causes the undiluted liquid injection section 180 to inject the undiluted liquid into the dialysis drainage channel 120 according to the preset neutralization start condition.

When injecting the undiluted solution from the undiluted solution injection unit 180 into the dialysis drainage channel 120, the control unit 10 closes the first on-off valve 182 and the second on-off valve 184, and closes the third on-off valve 183 and the fourth on-off valve. Each of the on-off valves 185 is opened, and the pump 181 is operated.

In the present embodiment, after starting the supply of the cleaning liquid from the cleaning liquid supply section 130, the control section 10 causes the cleaning liquid supplied from the cleaning liquid injection position 172, which is the connection position with the cleaning liquid supply section 130 in the dialysate flow path 171, to be dialyzed. The raw solution is injected from the raw solution injection unit 180 into the dialysis drainage flow channel 120 after the time required for the raw solution to reach the raw solution injection position 122, which is the connection position with the raw solution injection unit 180 in the drainage flow channel 120. In this case, the neutralization start condition is that the acid cleaning liquid has flowed to the stock solution injection position 122 . In this manner, the undiluted solution injection unit 180 may start operating around the time when the cleaning waste liquid reaches the undiluted solution injection position 122 with a delay from the start of operation of the cleaning liquid supply unit 130 .

As a result, the raw liquid is supplied from the raw liquid injection unit 180 before the washing liquid reaches the raw liquid injection position 122, so that the liquid property of the washing liquid can be suppressed from inclining toward the liquid property of the raw liquid.

Also, other neutralization start conditions may be set. In this case, the control unit 10 causes the undiluted solution injection unit 180 to inject the undiluted solution into the dialysis drainage channel 120 from the time when the pH of the washing drainage measured by the first pH sensor 191 exceeds the first set range. The first set range is, for example, the permissible range of the emission standard, which is pH 6.0 or more and 8.4 or less. That is, the neutralization start condition is that the pH of the cleaning waste liquid measured by the first pH sensor 191 exceeds the first set range. This allows neutralization to begin as soon as neutralization is required to meet emission standards.

Further, the control unit 10 increases the flow rate of the undiluted solution from the undiluted solution injection unit 180 from the time when the pH of the cleaning waste liquid measured by the first pH sensor 191 exceeds the second set range including the first set range. may The second set range is, for example, a previously assumed range of the pH of the cleaning waste liquid, which is pH 5.8 or more and 8.6 or less. By increasing the output of the pump 181, the flow rate of the concentrate from the concentrate injection section 180 can be increased. As a result, the stock solution can be injected from the stock solution injection section 180 in response to an increase in the amount of the stock solution required for neutralization.

As described above, by making the upper and lower limits of the second set range wider than the first set range by about 0.2, the concentration of the cleaning waste liquid and the measurement accuracy of the pH sensor vary. , the control unit 10 can be prevented from overreacting. That is, it is possible to suppress excessive output fluctuation of the pump 181 by the control unit 10 .

Furthermore, the control unit 10 determines that the pH of the drainage measured by the first pH sensor 191 exceeds the second set range from the time when the pH of the drainage measured by the first pH sensor 191 exceeds the second set range. The flow rate of the undiluted solution from the undiluted solution injection part 180 may be increased in proportion to the value. As a result, it is possible to stably neutralize the washing waste liquid.

Further, the control section 10 may increase the flow rate of the undiluted liquid from the undiluted liquid injection section 180 from the time when the pH of the waste liquid measured by the second pH sensor 192 exceeds the third set range. The third set range is, for example, the permissible range of the emission standard, which is pH 6.0 or more and 8.4 or less. As a result, the pH value of the cleaning waste liquid discharged into the sewage system can be prevented from being excessively inclined to the acidic side.

Furthermore, the control unit 10 determines that the pH of the drainage measured by the second pH sensor 192 exceeds the third set range from the time when the pH of the drainage measured by the second pH sensor 192 exceeds the third set range. The flow rate of the undiluted solution from the undiluted solution injection part 180 may be increased in proportion to the value. As a result, the pH value of the cleaning wastewater discharged into the sewage system can be fed back to increase the amount of the undiluted solution injected from the undiluted solution injection part 180 .

The control by the control unit 10 described above may be appropriately combined within a combinable range.

In the neutralization system 100 for the effluent flowing through the dialysis effluent flow path according to the first embodiment of the present invention, the cleaning effluent is neutralized using the undiluted solution. The pH of the effluent can be maintained within a set range.

Further, by neutralizing with the second stock solution during acid cleaning and neutralizing with the first stock solution during alkali cleaning, it is possible to neutralize the cleaning waste liquids from both the acid cleaning and the alkali cleaning.

(Embodiment 2)
A system for neutralizing waste fluid flowing through a dialysis waste fluid channel according to Embodiment 2 of the present invention will be described below. In the system for neutralizing the effluent flowing through the dialysis effluent channel according to the second embodiment of the present invention, the first powder dissolving device 140 and the second powder dissolving device 150 constitute the undiluted solution injection part, and 1 measuring unit is not provided, the neutralization system 100 for the effluent flowing through the dialysis waste fluid flow path according to the first embodiment of the present invention is different. Configurations that are similar to the neutralization system 100 for waste fluid flowing through the system will not be described again.

FIG. 3 is a system diagram showing the configuration of a system for neutralizing waste fluid flowing through a dialysis waste fluid channel according to Embodiment 2 of the present invention. In addition, in FIG. 3, only the portion connected to the dialysis drainage channel 120 is illustrated.

As shown in FIG. 3, in the neutralization system 200 for the effluent flowing through the dialysis effluent channel according to the second embodiment of the present invention, the dialysis effluent channel 120 is provided with a mixing section 223 and a buffer section 225. ing. Each of the mixing section 223 and the buffer section 225 is composed of a tank connected to the dialysis drainage channel 120 .

In this embodiment, the first tank built in the first powder dissolving device 140 is used as the first liquid storage section. A second tank built in the second powder dissolving device 150 is used as the second liquid storage part.

The stock solution injection part 180 uses a first pump built in the first powder dissolving device 140 and a second pump built in the second powder dissolving device 150 . In this embodiment, the first pH sensor 191 is not provided.

In the neutralization system 200 for the effluent flowing through the dialysis effluent channel according to the second embodiment of the present invention, the cleaning effluent is neutralized using the undiluted solution. The pH of the effluent can be maintained within a set range. Further, by neutralizing with the second stock solution during acid cleaning and neutralizing with the first stock solution during alkali cleaning, it is possible to neutralize the cleaning waste liquids from both the acid cleaning and the alkali cleaning.

It should be noted that the above-described embodiment disclosed this time is an example in all respects and does not serve as a basis for restrictive interpretation. Therefore, the technical scope of the present invention is not to be interpreted only by the above-described embodiments, but is defined based on the claims. In addition, all changes within the meaning and range of equivalents to the scope of claims are included.

10 control unit, 11 storage unit, 12 calculation unit, 100,200 neutralization system, 110 dialysis device, 120 dialysis drainage flow path, 122 stock solution injection position, 123,223 mixing unit, 124 gas separation unit, 125,225 buffer Section 126 Mesh 127 First measurement position 128 Second measurement position 129 End 130 Cleaning liquid supply section 140 First powder dissolving device 141 First liquid storage section 150 Second powder dissolving device 151 Second storage Liquid part 160 Reverse osmosis water generator 170 Dialysate preparation device 171 Dialysate flow path 172 Washing fluid injection position 180 Stock solution injection part 181 Pump 182 First on-off valve 183 Third on-off valve 184 Second On-off valve, 185 fourth on-off valve, 191 first pH sensor, 192 second pH sensor, 193 limestone, 194 exhaust fan.

Claims (10)

a dialysis drainage channel connected to the dialysis machine and through which the drainage flows;
a cleaning liquid supply unit connected to a dialysate flow path through which a dialysate flows and supplying a cleaning liquid for cleaning the dialysate flow path;
a liquid storage part for storing a stock solution having a liquid property opposite to that of the washing solution due to the dissolution of a part of the solute component of the dialysate ;
a stock solution injection unit connected to the dialysis drainage channel and injecting the stock solution from the liquid storage unit into the dialysis drainage channel;
a mixing unit located downstream of a connection position with the undiluted solution injection unit in the dialysis drainage channel and mixing the washing liquid and the undiluted solution;
a control unit electrically connected to each of the cleaning liquid supply unit and the undiluted solution injection unit;
The control unit determines the concentration and flow rate of the undiluted solution injected from the undiluted solution injection unit into the dialysis drainage channel according to the pH and flow rate of the cleaning liquid supplied from the cleaning liquid supply unit, and After the supply of the cleaning liquid from the cleaning liquid supply section is started, the raw liquid injection section injects the raw liquid into the dialysis drainage flow path according to preset neutralization start conditions. Neutralization system for waste fluid flowing through. The cleaning liquid supply unit is configured to be able to selectively supply cleaning liquids having different liquid properties,
The undiluted solution injection unit is configured to selectively inject a first undiluted solution and a second undiluted solution having different properties as the undiluted liquid into the dialysis drainage channel,
2. The dialysis system according to claim 1, wherein the controller injects one of the first undiluted solution and the second undiluted solution, which has a liquid property different from that of the cleaning liquid, from the undiluted solution injection unit into the dialysis drainage channel. Neutralization system for waste fluid flowing through the waste fluid channel. A first measuring unit for measuring the pH of the waste fluid is provided at a position upstream from a raw solution injection position that is a connection position with the raw solution injection unit in the dialysis waste fluid channel,
3. The system for neutralizing waste fluid flowing through the dialysis waste fluid flow path according to claim 1, wherein said control unit receives measurement results from said first measurement unit. A second measuring unit for measuring the pH of the effluent is provided at a position downstream of the mixing unit in the dialysis effluent channel,
The system for neutralizing waste fluid flowing through the dialysis waste fluid flow path according to any one of claims 1 to 3, wherein the control unit receives measurement results from the second measurement unit. After starting the supply of the cleaning liquid from the cleaning liquid supply section, the control section causes the cleaning liquid supplied from the cleaning liquid injection position, which is a connection position with the cleaning liquid supply section in the dialysate flow path, to flow into the dialysis drainage flow path. 1 to 3, wherein the undiluted solution is injected from the undiluted solution injection unit into the dialysis drainage channel after the time required for the undiluted solution to flow to the undiluted solution injection position, which is the connection position with the undiluted solution injection unit in the above, has elapsed. 5. A system for neutralizing wastewater flowing through the dialysis wastewater flow path according to any one of Claims 4 to 5. The control unit causes the undiluted solution injection unit to inject the undiluted solution into the dialysis effluent channel from the time when the pH of the effluent measured by the first measurement unit exceeds a first set range. 4. A neutralization system for the effluent flowing through the dialysis effluent flow path according to 3. The control unit increases the flow rate of the undiluted solution from the undiluted solution injection unit when the pH of the waste liquid measured by the first measurement unit exceeds a second set range including the first set range. 7. The system for neutralizing effluent flowing through the dialysis effluent flow path of claim 6. The control unit adjusts the pH of the drainage measured by the first measurement unit to the second setting range from the time when the pH of the drainage measured by the first measurement unit exceeds the second setting range. 8. The system for neutralizing effluent flowing through a dialysis effluent flow path according to claim 7, wherein the flow rate of said stock solution from said stock solution inlet is increased in proportion to an out-of-range value. 5. The control unit according to claim 4, wherein the control unit increases the flow rate of the undiluted solution from the undiluted solution injection unit when the pH of the waste liquid measured by the second measurement unit exceeds a third set range. A neutralization system for the effluent flowing through the dialysis effluent flow path. The control unit adjusts the pH of the waste liquid measured by the second measurement unit to the third setting range from the time when the pH of the waste liquid measured by the second measurement unit exceeds the third setting range. 10. The system for neutralizing effluent flowing through the dialysis effluent flow path of claim 9, wherein the flow rate of the stock solution from the stock solution inlet is increased in proportion to the out-of-range value.

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