JP2009269014A - Method for treating drainage including dialysis treatment drainage produced via dialysis treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for treating drainage including dialysis treatment drainage capable of treating with more downsized installations. <P>SOLUTION: The method for treating drainage including dialysis treatment drainage produced via dialysis treatment includes a first stage in which the pH of the drainage is measured as a water quality indication of the drainage and the drainage is treated through neutralizing treatment followed by membrane-separation treatment and activated sludge treatment when the pH is 6 or below, and a second stage, when the pH is over 6, in which an electric conductivity and a chlorine concentration are measured as water quality indications of the drainage, and when the electric conductivity is 10 mS or over and the chlorine concentration is 10 mg/L or below, the drainage undergoes neutralizing treatment followed by membrane-separation treatment and activated sludge treatment, and when the electric conductivity is below 10 mS or the chlorine concentration is over 10 mg/L, the drainage undergoes the neutralizing treatment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for treating waste water including dialysis waste water generated by dialysis treatment in a medical institution.

As shown in Table 1 below, wastewater containing dialysate generated by dialysis treatment in medical institutions was washed with wastewater when the dialyzer was washed with water, hypochlorite aqueous solution, in addition to the dialysate. Waste water when washed with acetic acid aqueous solution. For this reason, wastewater containing dialysate has a high BOD of 1,000 mg / L or more and cannot be directly discharged into sewage or rivers, and must be treated with a wastewater treatment facility such as a neutralization treatment or a septic tank.

  In addition, since wastewaters having different water qualities are sequentially discharged, there is a problem that the storage tank volume must be increased in order to equalize the water quality, or the aeration tank must be enlarged in order to perform BOD treatment on all wastewater.

Since the amount of effluent containing dialysate per patient can be as much as 1 m ³ / day, the treatment amount per medical institution is large, and in order to treat all effluents, the treatment level is lowered or treated. There was no choice but to introduce a large wastewater treatment facility.
JP-A-4-341394 JP 7-299490 A Japanese Patent No. 3083991

  This invention makes it a subject to provide the processing method of the waste_water | drain including the dialysis waste_water | drain produced by the dialysis treatment which can raise a BOD removal rate with a more compact installation.

The present invention provides the following inventions as means for solving the problems.
1. A method for treating wastewater including dialysis wastewater generated by dialysis treatment,
While monitoring the water quality of the wastewater with 1 or 2 or more indicators, depending on the water quality, processing is performed by applying one treatment selected from neutralization treatment, activated sludge treatment and membrane separation treatment, or 2 Alternatively, a wastewater treatment method in which the treatment methods 3 are applied in combination.
2. The wastewater treatment method according to claim 1, wherein the water quality monitoring index is selected from pH, electrical conductivity, and chlorine concentration.
3. There are four types of drainage: dialysis drainage generated by treating a patient with a dialysis machine, water that washed the dialysis machine, hypochlorite aqueous solution that washed the dialysis machine, and acetic acid aqueous solution that washed the dialysis machine. The processing method of the waste_water | drain of Claim 1 or 2 which contains.
4). A method for treating wastewater including dialysis wastewater generated by dialysis treatment,
Measure pH, electrical conductivity and chlorine concentration as water quality indicators of the waste water,
When the pH is 6 or less, after neutralization treatment, perform activated sludge treatment and / or membrane separation treatment,
When the pH exceeds 6, when the electrical conductivity is 10 mS or more and the chlorine concentration is 10 mg / L or less, the neutralization treatment is performed, and then the activated sludge treatment and / or the membrane separation treatment is performed. A method for treating wastewater, wherein neutralization is performed when the degree is less than 10 mS or the chlorine concentration exceeds 10 mg / L.
5. In the processing method of the waste_water | drain including the dialysis waste_water | drain produced by the dialysis treatment of any one of Claims 1-4,
Only a part of the total amount of wastewater to be treated is subjected to neutralization and one treatment selected from activated sludge treatment and membrane separation treatment, and the remaining amount of wastewater is subjected only to neutralization, and then separately. A wastewater treatment method that mixes treated water.

  If the wastewater treatment method of the present invention is applied, it is possible to exhibit high treatment capacity with a facility that is smaller than the conventional one, and to expect a reduction in operating cost.

  With reference to FIG. 1, a method for treating waste water including dialysis waste water generated by dialysis treatment of the present invention will be described. FIG. 1 is a diagram showing a processing flow of the processing method.

  The composition (type and proportion of components) of wastewater containing dialysis wastewater generated by dialysis treatment (hereinafter simply referred to as “drainage”) varies slightly depending on the medical institution. Usually, it has a composition as shown in Table 1.

  Drainage is sent from a drainage source (a pipe through which drainage flows or a tank that primarily stores the drainage) to each processing unit via a drainage supply line. In the previous stage, the water quality monitoring unit 1 performs a predetermined index. To monitor.

  The predetermined index is preferably one, two, or three selected from pH, electrical conductivity, and chlorine concentration in consideration of the composition of waste water, and preferably all three are used as monitoring indices.

  First, with the open / close valve 21 closed, the water quality monitoring unit 1 measures the pH, electrical conductivity, and chlorine concentration of the waste water that passes through the drain line 11a, and performs processing according to each index.

<When pH of waste water is 6 or less>
As apparent from the wastewater composition shown in Table 1, since the concentration of acetic acid-containing wastewater is high when the pH is 6 or less, the neutralization treatment and the treatment by the activated sludge treatment section and / or the membrane separation treatment section are performed. Required.

  For this reason, when the pH of the wastewater is 6 or less, the solution is sent to the neutralization processing unit 2 for neutralization with the open / close valve 21 opened.

  The wastewater after the neutralization treatment is sent to the activated sludge treatment section and / or the membrane separation processing section 3 from the liquid feed line 12 with the on-off valve 23 closed and the on-off valve 24 opened. Thereafter, the water is discharged from the discharge line 13a into a sewer or a river (when the legal discharge standard is satisfied).

  The activated sludge treatment unit 3 includes an activated sludge tank and an air diffuser, and the membrane separation unit 3 uses a treatment device using various known separation membranes such as a hollow fiber membrane, a tubular membrane, and a flat membrane. The activated sludge treatment and the membrane separation treatment may be performed in one tank. Examples of the activated sludge treatment unit and / or the membrane separation treatment unit 3 are described in, for example, JP-A-11-156360, JP-A-8-299979, JP-A-9-294996, and JP-A-2006-167550. Can be used.

  Either one of the membrane separation processing unit 3 and the activated sludge processing unit 3 may be used, or both of them may be used together, and both the membrane separation processing and the activated sludge treatment can be performed in one tank. It may be a thing.

<When pH of drainage exceeds 6>
(1) When the electrical conductivity of the wastewater is 10 mS or more and the chlorine concentration is 10 mg / L or less As is clear from the wastewater composition shown in Table 1,
When the pH exceeds 6, the proportion of acetic acid-containing wastewater is small,
When the electrical conductivity is 10 mS or more (that is, the amount of ions such as sodium ions and potassium ions or the salt concentration is large and the BOD is high), the ratio of dialysate drainage is large,
When the chlorine concentration is 10 mg / L or less, the ratio of sodium hypochlorite-containing wastewater is small.

  Therefore, the opening / closing valve 21 is opened and neutralized, and then sent from the liquid feed line 12 to the activated sludge treatment section and / or the membrane separation treatment 3 to be processed. Thereafter, the water is discharged from the discharge line 13a into a sewer or a river (when the legal discharge standard is satisfied).

(2) When the electrical conductivity of the wastewater is less than 10 mS or the chlorine concentration exceeds 10 mg / L As is clear from the wastewater composition shown in Table 1,
When the pH exceeds 6, the proportion of acetic acid-containing wastewater is small,
When the electrical conductivity is less than 10 mS (ie, the amount of ions such as sodium ions and potassium ions or the salt concentration is small and the BOD is low), the ratio of the dialysate drainage is small, the ratio of the water washing drainage is large,
When the chlorine concentration exceeds 10 mg / L, the proportion of waste water containing sodium hypochlorite is large.

  Therefore, the on-off valve 21 is opened, and the solution is fed to the neutralization processing unit 2 for neutralization. Thereafter, with the open / close valve 24 closed and the open / close valve 23 opened, the water is discharged from the discharge lines 13b and 13a to the sewer or river (when the legal discharge standard is satisfied).

  As a wastewater treatment method of the present invention, when treating wastewater containing dialysis wastewater generated by dialysis treatment by the above-described method, neutralization treatment and activated sludge are performed on a part of the total amount of wastewater to be treated. It is also possible to apply a method in which one treatment selected from the treatment and the membrane separation treatment is performed, only the neutralization treatment is performed on the remaining amount of waste water, and then separately treated treatment water is mixed.

  In areas where sewerage has not been developed and is released into rivers, BOD, etc. must be reduced sufficiently. However, in an area where sewerage is provided and wastewater is treated at the sewage treatment plant, the BOD flowing to the sewer may be 650 mg / L or less.

  For this reason, only one part of the total amount of wastewater to be treated is neutralized, and one treatment selected from activated sludge treatment and membrane separation treatment is performed to lower the BOD and obtain treated water (this treated water). Is called “completely treated water”).

  Then, only the neutralization process is performed on the remaining amount of waste water, and the BOD is obtained as it is (this treated water is referred to as “partially treated water”).

  Thereafter, the completely treated water and the partially treated water are mixed to obtain treated water having a pH near neutral and BOD satisfying the discharge standard to the sewer. The ratio of wastewater to be treated with respect to the total amount of wastewater for obtaining completely treated water can be selected in such a range that BOD satisfies the discharge standard for sewerage, but it is about 50% capacity. A method for processing a corresponding amount can be applied.

  After obtaining such completely treated water and partially treated water, by applying the method of mixing, the equipment required for activated sludge treatment and membrane separation treatment can be reduced in size, and the amount of energy required for treatment is further reduced. In addition, it does not adversely affect the environment.

Example 1
According to the processing flow shown in FIG. 1, the waste water shown in Table 1 was processed according to the procedure shown in FIG. Details of each processing unit are as follows. The total amount of wastewater to be treated was 30 m ³ .

[Water quality monitoring unit 1]
The following three types of water quality measuring instruments of inline type were installed before and after the treatment equipment to monitor the water quality.
pH measurement: Measured using a pH sensor IS-I type (manufactured by Iwaki).
Measurement of electrical conductivity: It was measured using a conductivity sensor CS150TC-Y type (manufactured by Iwaki).
Measurement of chlorine concentration: Measured using a residual free chlorine meter FCL-80 type (manufactured by Tokemi).

[Neutralization section 2]
The waste water storage part (volume 6 m ³ ) was divided into three, and the pH sensor IS-I type (manufactured by Iwaki) and the acid / alkali charging part were installed in the second tank.

[Activated sludge treatment section and membrane separation section 3]
A tank having a volume of 12 m ³ was prepared as an activated sludge treatment section and a membrane separation section. The tank is provided with a liquid inlet and a liquid outlet, and the inside is filled with activated sludge liquid. A diffuser is installed at the bottom downstream of the tank, and an immersion type membrane separator (membrane area 140 m ³ ) is installed downstream of the tank. The liquid flowing in from the liquid inlet was treated with activated sludge and then suction filtered using a membrane separator (flux 0.3 m / day, constant flow rate) to obtain a treated liquid. In addition, it aerated with the diffuser during the process.

As a result, the treatment amount of the treatment line (I) shown in FIG. 2 is 1.5 m ³ (5% of the total treatment amount), pH 6.8 to 7.4, BOD 2 mg / L or less, chlorine concentration 0.5 mg. / L or less,
The treatment amount of the treatment line (II) → (III) is 12 m ³ (40% of the total treatment amount), pH 6.9 to 7.5, BOD 2 mg / L or less, chlorine concentration 0.5 mg / L or less,
The treatment amount of the treatment line (II) → (IV) is 16.5 m ³ (55% of the total treatment amount), pH 6.8 to 7.4, BOD 3 mg / L or less, chlorine concentration 5 mg / L or less ,
It took about 14 hours to complete the processing of all the processing lines. This treated water could be discharged directly into the river.

Comparative Example 1
In the processing flow shown in FIG. 1, the water quality was not monitored by the water quality monitoring unit 1, the entire amount was processed by the neutralization processing unit 2, and the entire amount was further processed by the membrane separation unit / activated sludge processing unit 3. As a result, it took about 24 hours to complete the processing.

  As is clear from the comparison between Example 1 and Comparative Example 1, in the treatment method of the present invention, the water quality of the waste water is monitored based on a specific index, and the treatment according to the water quality is applied in combination. When processing equipment is used, processing time can be shortened. When processing is performed in the same processing time as in Example 1 in Comparative Example 1, it is necessary to shorten the processing time by increasing the processing equipment, so by applying the processing method of the present invention. Thus, the processing equipment can be made smaller than before. Moreover, since it is considered that the amount of energy required for operation can be reduced, reduction in operation cost can also be expected.

Example 2
In Example 1, the wastewater of 15 m ³ of waste water total amount 30 m ³ only, the same treatment as in Example 1 to obtain a fully processed water. And, for the drainage of the remainder amount of 15 m ³ volume, it performs only pH adjustment to obtain a partial process water. Thereafter, completely treated water and partially treated water were mixed to obtain mixed treated water having a pH of 6.8 to 7.6, a BOD of 550 mg / L or less, and a chlorine concentration of 5 mg / L or less. This mixed treated water can be discharged into the sewer as it is.

The figure which shows the processing flow of the processing method of the waste_water | drain of this invention. FIG. 3 is a diagram illustrating a procedure of a processing flow according to the first embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water quality monitor part 2 Neutralization process part 3 Membrane process and / or activated sludge process part 11a, 11b Waste water supply line 12 Liquid feed line 13a, 13b of the waste water after neutralization process Discharge line 21-24 Open / close valve

Claims (5)

A method for treating wastewater including dialysis wastewater generated by dialysis treatment,
While monitoring the water quality of the wastewater with 1 or 2 or more indicators, depending on the water quality, either 1 treatment selected from neutralization treatment, activated sludge treatment and membrane separation treatment is applied, or 2 Alternatively, a wastewater treatment method in which the treatment methods 3 are applied in combination.   The wastewater treatment method according to claim 1, wherein the water quality monitoring index is selected from pH, electrical conductivity, and chlorine concentration.   There are four types of drainage: dialysis drainage generated by treating a patient with a dialysis machine, water that washed the dialysis machine, hypochlorite aqueous solution that washed the dialysis machine, and acetic acid aqueous solution that washed the dialysis machine. The processing method of the waste_water | drain of Claim 1 or 2 which contains. A method for treating wastewater including dialysis wastewater generated by dialysis treatment,
Measure pH, electrical conductivity and chlorine concentration as water quality indicators of the waste water,
When the pH is 6 or less, after neutralization treatment, perform activated sludge treatment and / or membrane separation treatment,
When the pH exceeds 6, when the electrical conductivity is 10 mS or more and the chlorine concentration is 10 mg / L or less, the neutralization treatment is performed, and then the activated sludge treatment and / or the membrane separation treatment is performed. A method for treating wastewater, wherein neutralization is performed when the degree is less than 10 mS or the chlorine concentration exceeds 10 mg / L. In the processing method of the waste_water | drain including the dialysis waste_water | drain produced by the dialysis treatment of any one of Claims 1-4,
Only a part of the total amount of wastewater to be treated is subjected to neutralization treatment and one treatment selected from activated sludge treatment and membrane separation treatment, and the remaining amount of wastewater is subjected only to neutralization treatment, and thereafter separately. A wastewater treatment method that mixes treated water.

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