JP7200518B2 - Wastewater treatment method and wastewater treatment equipment - Google Patents

Description

The present invention relates to a wastewater treatment method and a wastewater treatment apparatus.

When discharging wastewater from factories, business establishments, etc. into public water areas, in Japan, the Prime Minister's Office Ordinance (1971 Prime Minister's Office Ordinance No. No. 35) must meet the effluent standards (so-called uniform effluent standards). Wastewater from factories, business establishments, etc. contains suspended solids, organic matter, metallic elements, etc., and is discharged into public water areas after being treated to meet uniform wastewater standards.

In recent years, some countries, mainly in Europe and the United States, have introduced wastewater management systems using biological responses. For example, in the United States, due to the revision of the Clean Water Act, a wastewater evaluation method using biological responses has been added to monitoring tools under the name of WET (Whole Effluent Toxicity) test. In Japan, the Ministry of the Environment is also considering the use of wastewater management methods that utilize biological responses.

Even if the wastewater satisfies the uniform wastewater standards, there are cases in which favorable results cannot be obtained when evaluating the presence or absence of toxicity in biological response tests. Therefore, we propose a water treatment method that uses an iron-based coagulant to coagulate water that satisfies uniform wastewater standards, reduces metal ions in the water, and improves the quality of the water so that it can pass the biological response test. (Patent Document 1).

JP 2016-165688 A

Toxic factors that affect organisms in biological response tests are various, such as the concentration and form of specific substances such as organic substances and metal elements, and their interactions (combined effects). The water treatment method described in Patent Document 1 is effective when the main toxic factor that affects living organisms is metal ions. If interactions and other factors are involved in toxicity, it may not pass the biological response test.

INDUSTRIAL APPLICABILITY The present invention provides a wastewater treatment method and a wastewater treatment apparatus capable of obtaining treated water in which various toxic factors affecting living organisms are reduced.

The present invention has the following aspects.
<1> An organic matter adsorbent is added to the first treated water obtained by treating wastewater so as to satisfy uniform wastewater standards to obtain a mixture containing the second treated water and the organic matter absorbent, and the mixture is solid-liquid separated into the second treated water and the organic adsorbent , wherein a biological response test is performed on a sample collected from the first treated water, and toxicity needs to be improved When it is evaluated that there is, the organic matter adsorbent is added to the first treated water, and the amount of the organic matter adsorbent added is the TOC concentration or metal element concentration of the first treated water A wastewater treatment method that adjusts based on at least some information . However, the uniform effluent standard is the effluent standard stipulated in the Prime Minister's Office Ordinance (Prime Minister's Office Ordinance No. 35 of 1971) that stipulates effluent standards based on the provisions of Article 3, Paragraph 1 of the Water Pollution Control Law. . In addition, the biological response test was organized by the "Study Group on Water Environment Management Techniques Using Biological Responses" established by the Ministry of the Environment, and was published by the Ministry of the Environment in December 2017. In the current summary of technical matters of evaluation and management (improvement) methods (as of the end of November 2017), "Evaluate the toxicity of chemical substances by confirming (using) the response of organisms to chemical substances. defined as “test”.
<2 > The wastewater treatment method according to <1> above, wherein solid-liquid separation by a membrane or solid-liquid separation by sedimentation is used as the solid-liquid separation.
< 3 > The wastewater treatment method according to <1> or <2> , wherein a coagulant is added to the second treated water containing the organic matter adsorbent.
< 4 > The wastewater treatment method according to any one of <1> to < 3 >, wherein the organic adsorbent contains powdered activated carbon.
< 5 > The waste water treatment method according to any one of <1> to < 4 >, further comprising adding a metal adsorbent to the first treated water.
< 6 > The wastewater treatment method according to < 5 >, wherein a cation exchange resin or a chelate resin is used as the metal adsorbent.
< 7 > Primary treatment means for treating wastewater to meet uniform wastewater standards to obtain a first treated water, and adsorption treatment for obtaining a second treated water by treating the first treated water with an organic adsorbent. a tank, an organic adsorbent adding means for adding the organic adsorbent to the first treated water, and a solid-liquid separation means for solid-liquid separating the second treated water and the organic adsorbent , The organic matter adsorbent addition means performs a biological response test on the sample collected from the first treated water, and if the toxicity is evaluated as needing to be improved, the organic matter adsorbs to the first treated water. Further, the addition amount of the organic matter adsorbent added to the first treated water by the organic matter adsorbent adding means is set to at least either the TOC concentration or the metal element concentration of the first treated water. A wastewater treatment system with a controller that adjusts based on the information . However, the uniform effluent standard is the effluent standard stipulated in the Prime Minister's Office Ordinance (Prime Minister's Office Ordinance No. 35 of 1971) that stipulates effluent standards based on the provisions of Article 3, Paragraph 1 of the Water Pollution Control Law. . In addition, the biological response test was organized by the "Study Group on Water Environment Management Techniques Using Biological Responses" established by the Ministry of the Environment, and was published by the Ministry of the Environment in December 2017. In the current summary of technical matters of evaluation and management (improvement) methods (as of the end of November 2017), "Evaluate the toxicity of chemical substances by confirming (using) the response of organisms to chemical substances. defined as “test”.
< 8 > The waste water treatment apparatus according to < 7 >, wherein the solid-liquid separation means is a membrane separator or a coagulating sedimentation tank.
< 9 > The waste water treatment apparatus according to < 7 > or < 8 >, further comprising coagulant addition means for adding a coagulant to the second treated water containing the organic adsorbent.
< 10 > The waste water treatment apparatus according to any one of < 7 > to < 9 >, further comprising metal adsorbent adding means for adding a metal adsorbent to the first treated water .

According to the wastewater treatment method and the wastewater treatment apparatus of the present invention, treated water in which various toxic factors affecting organisms are reduced can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows an example of the waste water treatment apparatus of this invention. FIG. 2 is a schematic configuration diagram showing another example of the waste water treatment apparatus of the present invention;

The following term definitions apply throughout the specification and claims.
"Uniform effluent standards" are effluent standards stipulated in the Prime Minister's Office Ordinance (Prime Minister's Office Ordinance No. 35 of 1971), which stipulates effluent standards based on the provisions of Article 3, Paragraph 1 of the Water Pollution Control Law. .
The "biological response test" was organized by the "Study Group on Water Environment Management Techniques Using Biological Responses" established by the Ministry of the Environment, and was published by the Ministry of the Environment in December 2017 as part of the "Evaluation of Water Environments Using Organisms."・As of the end of November 2017, in the current summary of technical matters related to management (improvement) methods, “a test to evaluate the toxicity of chemical substances by confirming (utilizing) the response of living organisms to chemical substances”. ” is defined as
In the present specification and claims, "-" indicating a numerical range means that the numerical values before and after it are included as lower and upper limits.
The dimensional ratios in FIGS. 1 and 2 are different from the actual ones for convenience of explanation.

<Wastewater treatment equipment>
The wastewater treatment apparatus of the present invention comprises primary treatment means for treating wastewater so as to satisfy uniform wastewater standards to obtain first treated water, and second treated water by treating the first treated water with an organic matter adsorbent. , an organic adsorbent adding means for adding an organic adsorbent to the first treated water, and a solid-liquid separation means for solid-liquid separating the organic adsorbent from the second treated water.
The waste water treatment apparatus of the present invention may further include a coagulant adding means for adding a coagulant to the second treated water containing the organic matter adsorbent, if necessary.
The wastewater treatment apparatus of the present invention may further comprise metal adsorbent addition means for adding a metal adsorbent to the first treated water, if necessary.

(First embodiment)
FIG. 1 is a schematic configuration diagram showing a first embodiment of a waste water treatment apparatus of the present invention.
The wastewater treatment apparatus 1 includes a primary treatment means 10 for treating wastewater to obtain a first treated water so as to satisfy uniform wastewater standards, and a first treated water treated with an organic matter adsorbent to obtain a second treated water. a membrane separator 14 for separating the second treated water from the organic matter adsorbent; and a storage tank 18 for storing the second treated water.

The waste water treatment apparatus 1 further includes an organic adsorbent adding means 20 for adding an organic adsorbent to the first treated water in the adsorption treatment tank 12, and a metal adsorbent to the first treated water in the adsorption treatment tank 12. A metal adsorbent addition means 22 to be added, a coagulant addition means 24 for adding a coagulant to the second treated water containing the organic matter adsorbent in the membrane separation device 14, and an organic matter adsorbent in the membrane separation device 14 and pH adjusting means 26 for adjusting the pH of the second treated water.

The wastewater treatment apparatus 1 further includes a wastewater introduction line 30 for introducing wastewater discharged from factories, business establishments, etc. that does not meet the uniform wastewater standards into the primary treatment means 10, and the first treatment obtained by the primary treatment means 10. A first treated water transfer line 32 for transferring water to the adsorption treatment tank 12, and a second treated water for transferring the second treated water containing the organic adsorbent obtained in the adsorption treatment tank 12 to the membrane separation device 14. a transfer line 34;

Examples of the primary treatment means 10 include activated sludge treatment equipment, coagulating sedimentation tanks, adsorption treatment tanks, oxidation treatment tanks, combinations thereof, and the like.

The adsorption treatment tank 12 includes a tank main body 38 and an agitating device (not shown) for agitating the waste water and the like in the tank main body 38 .
Various measuring devices (not shown) for measuring the water temperature, total organic carbon (hereinafter also referred to as "TOC") concentration, metal element concentration, etc. in the tank body 38 are installed in the adsorption reaction tank 12 as necessary. may be provided.

The membrane separation device 14 includes a water tank 40, a membrane module 42 arranged in the water tank 40, a permeated water transfer line 44 for transferring the second treated water that has permeated the separation membrane of the membrane module 42 to the storage tank 18, A decompression pump 46 provided in the middle of the permeate transfer line 44, an air diffuser 48 arranged below the membrane module 42, an air supply line 52 for supplying air from the blower 50 to the air diffuser 48, and the membrane module. A floc extracting line 54 for extracting flocs containing an organic adsorbent accumulated at the bottom of the water tank 40 without passing through the separation membrane of 42, and a floc extracting valve 56 provided in the middle of the floc extracting line 54. .
The separation membranes of the membrane module 42 include hollow fiber membranes, flat membranes, and the like.
The membrane separation device 14 may be provided with various measuring devices (not shown) for measuring the water temperature, TOC concentration, metal element concentration, etc. in the water tank 40 as necessary.

The organic adsorbent adding means 20 includes an organic adsorbent storage tank 60 for storing the organic adsorbent, an organic adsorbent supply line 62 for supplying the organic adsorbent in the organic adsorbent storage tank 60 to the adsorption treatment tank 12, and an organic adsorbent. and a pump 64 provided in the middle of the agent supply line 62 .

The metal adsorbent adding means 22 includes a metal adsorbent storage tank 66 for storing the metal adsorbent, a metal adsorbent supply line 68 for supplying the metal adsorbent in the metal adsorbent storage tank 66 to the adsorption treatment tank 12, and a metal adsorbent. and a pump 70 provided in the middle of the agent supply line 68 .

The coagulant addition means 24 includes a coagulant storage tank 72 that stores the coagulant, a coagulant supply line 74 that supplies the coagulant in the coagulant storage tank 72 to the membrane separation device 14, and a and a pump 76 provided.

The pH adjusting means 26 includes an acid storage tank 78 that stores acid, an acid supply line 80 that supplies the acid in the acid storage tank 78 to the membrane separation device 14, a pump 82 provided in the middle of the acid supply line 80, an alkali storage tank 84 for storing alkali; an alkali supply line 86 for supplying the alkali in the alkali storage tank 84 to the membrane separation device 14; a pump 88 provided in the middle of the alkali supply line 86; A pH measuring device 90 for measuring the pH of the second treated water containing the organic adsorbent, and a control device 92 electrically connected to the pumps 82 and 88 and the pH measuring device 90 are provided.

The control device 92 controls the pump 82 of the acid supply line 80 and the pump 86 of the alkali supply line 86 based on the pH information of the second treated water containing the organic matter adsorbent in the membrane separation device 14 measured by the pH measurement device 90 . It controls the output of 88. The control device 92 controls the organic adsorbent supply line based on information such as the water temperature, TOC concentration, and metal element concentration in the tank body 38 measured by various measuring devices (not shown) provided in the adsorption reaction tank 12. It may control the output of the pump 64 of 62 and the pump 70 of the metal adsorbent supply line 68 .

The control device 92 includes an interface section (not shown), a storage section (not shown), a processing section (not shown), and the like.
The interface section electrically connects the pumps 82, 88 and pH measuring device 90 with the processing section. The interface section may electrically connect the pumps 64, 70, various measuring devices provided in the adsorption reaction tank 12, and the processing section.

The storage unit stores the setting range of the pH of the second treated water containing the organic matter adsorbent in the membrane separation device 14, and the like. The storage unit may store the setting range of the addition amount of the organic adsorbent and the metal adsorbent according to the water temperature, TOC concentration, metal element concentration, etc. of the first treated water in the adsorption reaction tank 12. .

Based on the pH information from the pH measuring device 90, the processing unit adjusts the pH of the second treated water containing the organic matter adsorbent in the membrane separation device 14 to be within the set pH range stored in the storage unit. Secondly, it controls the outputs of the pumps 82 and 88 . Based on information such as the water temperature, TOC concentration, metal element concentration, etc. from various measuring devices provided in the adsorption reaction tank 12, the treatment unit adds organic matter adsorbents and metals to the first treated water in the adsorption reaction tank 12. The outputs of the pumps 64 and 70 may be controlled so that the amount of adsorbent to be added is within the set range of the amount of addition stored in the storage unit.

The processing unit may be realized by dedicated hardware, and is composed of a memory and a central processing unit (CPU), and loads and executes a program for realizing the functions of the processing unit into the memory. The function may be realized by
An input device, a display device, and the like may be connected to the control device 92 as peripheral devices. Examples of input devices include input devices such as display touch panels, switch panels, and keyboards, and examples of display devices include liquid crystal display devices and CRTs.

(Second embodiment)
FIG. 2 is a schematic configuration diagram showing a second embodiment of the waste water treatment apparatus of the present invention.
The wastewater treatment device 2 includes a primary treatment means 10 for treating wastewater to obtain a first treated water by treating the wastewater so as to satisfy the uniform wastewater standard, and a second treated water by treating the first treated water with an organic matter adsorbent. a coagulating sedimentation tank 16 for separating the second treated water from the organic matter adsorbent; and a storage tank 18 for storing the second treated water.

The waste water treatment apparatus 1 further includes an organic adsorbent adding means 20 for adding an organic adsorbent to the first treated water in the adsorption treatment tank 12, and a metal adsorbent to the first treated water in the adsorption treatment tank 12. Metal adsorbent addition means 22 to be added, coagulant addition means 24 for adding a coagulant to the second treated water containing the organic matter adsorbent in the coagulation sedimentation tank 16, and the organic matter adsorbent in the coagulation sedimentation tank 16 and pH adjusting means 26 for adjusting the pH of the second treated water.

The wastewater treatment apparatus 1 further includes a wastewater introduction line 30 for introducing wastewater discharged from factories, business establishments, etc. that does not meet the uniform wastewater standards into the primary treatment means 10, and the first treatment obtained by the primary treatment means 10. A first treated water transfer line 32 for transferring water to the adsorption treatment tank 12, and a second treated water for transferring the second treated water containing the organic adsorbent obtained in the adsorption treatment tank 12 to the coagulation sedimentation tank 16. A transfer line 34 and a supernatant liquid transfer line 36 for transferring the supernatant liquid (second treated water) in the coagulation sedimentation tank 16 to the storage tank 18 are provided.
Hereinafter, the same components as those of the waste water treatment apparatus 1 shown in FIG.

The coagulating sedimentation tank 16 includes a tank body 94, a floc extraction line 96 for extracting flocs containing an organic adsorbent accumulated in the bottom of the tank body 94, and a floc extraction valve 98 provided in the middle of the floc extraction line 96. and

(Other embodiments)
The wastewater treatment apparatus of the present invention comprises primary treatment means for treating wastewater so as to satisfy uniform wastewater standards to obtain first treated water, and second treated water by treating the first treated water with an organic matter adsorbent. , an organic adsorbent addition means for adding an organic adsorbent to the first treated water, and a solid-liquid separation means for solid-liquid separation between the second treated water and the organic adsorbent. There is no limitation to the wastewater treatment apparatus shown in the drawings.
For example, the storage tank 18 may be omitted.
Also, one or more of the metal adsorbent adding means 22, the coagulant adding means 24 and the pH adjusting means 26 may be omitted.
Alternatively, the adsorption treatment tank may be divided into a plurality of tanks, and the organic adsorbent adding means and the metal adsorbent adding means may be provided in different adsorption treatment tanks.
Alternatively, the operation of the pump 82 and the pump 88 may be switched manually based on the pH measured by the pH measuring device 90 without providing the control device 92 .

<Wastewater treatment method>
In the wastewater treatment method of the present invention, an organic adsorbent is added to the first treated water obtained by treating the wastewater so as to satisfy the uniform wastewater standard to obtain the second treated water, and the second treated water is obtained. This is a method for solid-liquid separation of water and an organic adsorbent.
In the waste water treatment method of the present invention, if necessary, a flocculant may be added to the second treated water containing the organic adsorbent.
In the waste water treatment method of the present invention, a metal adsorbent may be further added to the first treated water, if necessary.

(First embodiment)
Wastewater treatment using the wastewater treatment apparatus 1, which is the first embodiment of the wastewater treatment apparatus of the present invention, is performed as follows.

Wastewater discharged from factories, business establishments, etc. and not meeting uniform wastewater standards is introduced into a primary treatment means 10 through a wastewater introduction line 30. - 特許庁
In the primary treatment means 10, wastewater is primarily treated so as to meet uniform wastewater standards to obtain first treated water. The primary treatment includes activated sludge treatment, coagulation sedimentation, adsorption treatment, oxidation treatment, and combinations thereof.

The first treated water obtained by the primary treatment means 10 is transferred to the adsorption treatment tank 12 through the first treated water transfer line 32 .
By driving the pump 64 in the organic adsorbent addition means 20 , the organic adsorbent in the organic adsorbent storage tank 60 is supplied to the adsorption treatment tank 12 through the organic adsorbent supply line 62 , and the second Add to the treated water of 1.
If necessary, the pump 70 in the metal adsorbent addition means 22 is driven to supply the metal adsorbent in the metal adsorbent storage tank 66 to the adsorption treatment tank 12 through the metal adsorbent supply line 68, and adsorption treatment is performed. It is added to the first treated water in tank 12 .

Examples of organic adsorbents include activated carbon and anion exchange resins. Activated carbon is preferred because it is highly effective in reducing organic substances and metal elements. As the activated carbon, powdered activated carbon is preferable because it has a large specific surface area and a high reaction rate. The powdered activated carbon is preferably slurried and stored in the organic adsorbent reservoir 60 for supply by the pump 64 .
The amount of the organic adsorbent to be added is preferably adjusted according to the water temperature, TOC concentration, metal element concentration, and the like of the first treated water. For example, the amount of the organic adsorbent to be added is preferably such that the concentration of the organic adsorbent in the first treated water is 10 to 5000 times the TOC concentration. The amount of the organic adsorbent to be added is determined by the control device based on information such as the water temperature, TOC concentration, and metal element concentration in the tank body 38 measured by various measuring devices (not shown) provided in the adsorption reaction tank 12. 92 may be regulated by controlling the output of pump 64 in organic sorbent supply line 62 .

Examples of metal adsorbents include cation exchange resins and chelate resins. The metal adsorbent is preferably stored in the metal adsorbent reservoir 66 in slurry form for supply by the pump 70 .
The amount of the metal adsorbent to be added is preferably adjusted according to the water temperature, TOC concentration, metal element concentration, etc. of the first treated water. The amount of the metal adsorbent to be added is determined by the control device based on information such as the water temperature, TOC concentration, and metal element concentration in the tank body 38 measured by various measuring devices (not shown) provided in the adsorption reaction tank 12. 92 may be regulated by controlling the output of pump 70 in metal sorbent supply line 68 .

In the adsorption treatment tank 12, the first treated water, the organic adsorbent, and optionally the metal adsorbent are agitated and mixed to mix the first treated water with the organic adsorbent and optionally the metal adsorbent. to obtain a second treated water.
The adsorption treatment is preferably performed until the TOC concentration in the second treated water becomes 10 mg/L or less, more preferably 5 mg/L or less. If the TOC concentration in the second treated water is equal to or lower than the upper limit of the above range, it is difficult to assess the need for improvement in toxicity when a biological response test is conducted.

The second treated water containing the organic matter adsorbent obtained in the adsorption treatment tank 12 is transferred to the membrane separation device 14 through the second treated water transfer line 34 .
If necessary, the pump 76 in the flocculant addition means 24 is driven to supply the flocculant in the flocculant storage tank 72 to the membrane separation device 14 through the flocculant supply line 74. It is added to the second treated water containing the organic adsorbent.

Examples of flocculants include inorganic flocculants and organic flocculants. An inorganic flocculant and an organic flocculant may be used in combination. Examples of inorganic flocculants include polyaluminum chloride (PAC), ferric chloride, and polyiron. Examples of organic flocculants include anionic polymer flocculants, cationic polymer flocculants, nonionic polymer flocculants, and amphoteric polymer flocculants.
The amount of the coagulant to be added is preferably adjusted according to the concentrations of the organic adsorbent and the metal adsorbent in the second treated water containing the organic adsorbent.

The pH of the second treated water containing the organic matter adsorbent in the membrane separation device 14 is preferably 5 to 8, more preferably 5.5 to 7.5. If the pH of the second treated water containing the organic adsorbent is within the above range, the flocculation reaction of the organic adsorbent and the metal adsorbent by the flocculant will easily proceed, and the floc containing the organic adsorbent and the metal adsorbent will be stable. formed by When accelerating the adsorption reaction by the organic adsorbent, the pH is preferably 5 or more and less than 8, more preferably 5.5 to 6.5.
The pH of the second treated water containing the organic adsorbent is determined by the control device 92 based on the pH information of the second treated water containing the organic adsorbent in the membrane separation device 14 measured by the pH measuring device 90. It is regulated by controlling the output of pump 82 in acid supply line 80 and pump 88 in alkali supply line 86 .

When the pH information of the second treated water containing the organic adsorbent in the membrane separation device 14 measured by the pH measuring device 90 exceeds the upper limit of the pH setting range stored in the storage unit, the processing unit The pump 82 of the acid supply line 80 is driven to supply the acid in the acid storage tank 78 to the membrane separation device 14 through the acid supply line 80, and the second treated water containing the organic matter adsorbent in the membrane separation device 14. Add to. After that, when the pH information of the second treated water containing the organic adsorbent in the membrane separation device 14 measured by the pH measuring device 90 falls within the pH setting range stored in the storage unit, the processing unit causes the pump 82 in the acid supply line 80 to stop.

When the pH information of the second treated water containing the organic adsorbent in the membrane separation device 14 measured by the pH measuring device 90 is less than the lower limit value of the pH setting range stored in the storage unit, the processing unit , the pump 88 of the alkali supply line 86 is driven to supply the alkali in the alkali storage tank 84 to the membrane separation device 14 through the alkali supply line 86, and the second treatment containing the organic adsorbent in the membrane separation device 14 is performed. Add to water. After that, when the pH information of the second treated water containing the organic adsorbent in the membrane separation device 14 measured by the pH measuring device 90 falls within the pH setting range stored in the storage unit, the processing unit causes the pump 88 in the alkali supply line 86 to stop.

In the membrane separation device 14, by stirring and mixing the second treated water containing the organic adsorbent and the flocculant, the organic adsorbent and the metal adsorbent are aggregated, and the organic adsorbent and the metal adsorbent are contained. form flocs.
By driving a decompression pump 46 provided in the middle of the permeate transfer line 44, the secondary side of the separation membrane of the membrane module 42 connected to one end of the permeate transfer line 44 is brought into a decompressed state. Only the second treated water is allowed to permeate the decompressed secondary side of the separation membrane of the membrane module 42 to separate the second treated water and flocs.
The second treated water that has passed through the separation membranes of the membrane module 42 is transferred to the storage tank 18 through the permeate transfer line 44 .

Air is supplied from the blower 50 to the diffuser pipe 48 through the air supply line 52 . Air is bubbled from an air diffuser 48 arranged below the membrane module 42 to wash the surfaces of the separation membranes of the membrane module 42 .
When the concentration of the organic adsorbent and the metal adsorbent in the second treated water containing the organic adsorbent in the membrane separation device 14 increases, the floc extraction valve 56 provided in the floc extraction line 54 is opened. , the flocs accumulated at the bottom of the water tank 40 without passing through the separation membrane of the membrane module 42 are extracted to the outside through a floc extraction line 54. - 特許庁

After the second treated water is temporarily stored in the storage tank 18, it is discharged into public water areas such as rivers, lakes, harbors, and coastal sea areas. It is preferable that the second treated water stored in the storage tank 18 is periodically sampled and subjected to a biological response test to evaluate the presence or absence of toxicity.

(Second embodiment)
Wastewater treatment using the wastewater treatment apparatus 2, which is the second embodiment of the wastewater treatment apparatus of the present invention, is performed by performing solid-liquid separation by the coagulation sedimentation tank 16 instead of solid-liquid separation by the membrane separator 14. The wastewater treatment is performed in the same manner as the wastewater treatment using the wastewater treatment equipment 1, which is the first embodiment of the wastewater treatment equipment of the present invention.

In the coagulation-sedimentation tank 16, the second treated water containing the organic adsorbent and the coagulant are stirred and mixed to aggregate the organic adsorbent and the metal adsorbent, thereby containing the organic adsorbent and the metal adsorbent. form flocs.
The second treated water, which is the supernatant, and the floc, which is the sediment, are solid-liquid separated, and the second treated water is transferred to the storage tank 18 through the supernatant liquid transfer line 36 . A floc extraction valve 98 provided in the middle of the floc extraction line 96 is opened to extract the floc accumulated at the bottom of the coagulating sedimentation tank 16 through the floc extraction line 96 to the outside.

(Biological response test)
In the wastewater treatment method of the present invention, the biological response test is performed on the sample collected from the first treated water, and when it is evaluated that the toxicity needs to be improved, the organic matter adsorbent is added to the first treated water. You may make it add.
Specifically, a test set up in a factory, business establishment, etc. is conducted for a sample collected from the first treated water in a treatment facility that treats wastewater from a factory, business establishment, etc. so as to meet uniform wastewater standards. Biological response tests are conducted at equipment, external testing institutes, etc. As a result of the biological response test, if it is evaluated that the toxicity needs to be improved, measures such as adding an organic adsorbent to the first treated water will be taken at treatment facilities such as factories and business establishments.

Bio-response tests applied to wastewater and environmental water are widely used in domestic and overseas chemical substance management and aquatic life conservation systems.
In biological response tests, three groups of organisms, fish, invertebrates (such as crustaceans), and algae, are widely used in consideration of the trophic level of the organisms.

Biological response tests whose reliability has been secured internationally include, for example, the following tests.
・OECD Test Guideline 212, "Fish, Short-term Toxicity Test on Embryo and Sac-fry Stages"
・ISO 15088:2007, "Water quality - Determination of the acute toxicity of waste water to zebrafish eggs (Danio rerio)"
- US Environmental Protection Agency WET test 1001.0, "Fathed Minnow, Pimephales promelas, embryo-larval survival and teratogenicity test method"
・Environment Canada, “Test of Reproduction and Survival Using the Cladoceran Ceriodaphnia dubia”
- US Environmental Protection Agency WET test 1002.0, "Ceriodaphnia 7-day survival and reproduction test"
・ASTM guidelines, ``Proposed new standard guide for conducting three broad, renewed toxicity tests with Ceriodaphnia dubia''
・OECD Test Guideline 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test"
・ISO 8692:2004, "Water quality - Freshwater algal growth inhibition test with unicellular green algae"
- U.S. Environmental Protection Agency WET test 1003.0, "Green alga, Selenastrum capricornutum, growth test"

Test methods that are internationally recognized as being able to obtain reliable test results, including reproducibility, and the test organisms specified in them are limited to certain ones. In addition, apart from the limitations arising from these testing methods, the number of species that can be stably procured and used domestically is limited due to practical limitations such as the ease of breeding.

In Japan, in addition to the status of these test species, the Ministry of the Environment announced in November 2015, “Application to wastewater management methods using biological responses” (Study on water environment management methods using biological responses) In the test bill proposed in the meeting report),
・Reliability is ensured internationally by OECD test guidelines, US Environmental Protection Agency (EPA) WET test, etc.
・Chronic toxicity can be evaluated in a short period of time (relatively low cost),
・It is feasible in domestic testing laboratories,
Considering these points, a test method is presented for 3 groups of organisms (fish, invertebrates and algae).

This test bill was put together by the "Bioassay Technology Review Subcommittee for Wastewater (Environmental Water) Management" of the "Study Group on Water Environment Management Methods Using Biological Responses" established by the Ministry of the Environment. This is the "Wastewater Test Method Using Biological Responses (Study Plan)" announced in March. In this test method, "short-term toxicity test method using embryonic and larval stage fish", "daphnia reproduction test method using Cicada flea", and "growth inhibition test method using freshwater algae" are indicated.

"Short-term toxicity test method using embryonic and larval stage fish" is a test method based on OECD Test Guideline 212, ISO 15088: 2007, US Environmental Protection Agency WET Test 1001.0, etc., and zebrafish or medaka are recommended species.
"Daphnia breeding test method using Cicada flea" is a test method based on the test method of the Canadian Ministry of the Environment, the WET test 1002.0 of the US Environmental Protection Agency, ASTM guidelines, etc., and Cicada flea is the recommended species. It is said that
"Growth inhibition test method using freshwater algae" is a test method based on OECD Test Guideline 201, ISO 8692: 2004, WET test 1003.0 of the US Environmental Protection Agency, etc., and Muremikazukimo is a recommended species. there is

As for which test method to adopt as a biological response test, each business operator should make an appropriate judgment in consideration of the purpose of utilizing the biological response test. In the future, when the Ministry of the Environment officially establishes a water environment evaluation and management (improvement) method using organisms, biological response tests may be conducted according to this method. In addition, it is basic to select from the three groups of organisms (fish, invertebrates and algae) when conducting the biological response test, but it is not always necessary to use all three groups of organisms. For example, in December 2017, the Ministry of the Environment published the ``Preliminary summary of technical matters concerning methods for evaluating and managing (improving) the water environment using organisms (as of the end of November 2017)''. It is basic to select from 3 groups of organisms (fish, invertebrates and algae) when conducting response tests, but it is not always necessary to use all 3 groups of organisms. As a case where it is considered reasonable to omit the test for the other species, for example, when the wastewater properties are stable, there is no ecological impact in the past consecutive tests using a certain species. In addition, it is also possible to consider the conditions of the water area to which the wastewater is discharged.”

Each business operator should appropriately determine how to evaluate the results of the biological response test, taking into consideration the purpose of utilizing the biological response test. For example, in December 2017, the Ministry of the Environment published the "Current Summary of Technical Matters Concerning Methods for Evaluation and Management (Improvement) of Water Environments Using Organisms (as of the end of November 2017)." It is necessary for each business operator to decide how to evaluate and interpret the results of the biological response test used for wastewater, considering their own purpose of using this method.” , As an example of evaluation criteria, when using a method for the purpose of conserving aquatic organisms at the destination of wastewater discharge, "an arbitrary impact evaluation value (TU value, etc.) calculated in relation to the actual state of the water area at which wastewater is discharged" ."a.

Here, TU (Toxic Unit) is an amount calculated by TU=100/NOEC when determining the maximum no-effect concentration (NOEC) in a biological response test. Higher TU indicates stronger toxicity.
NOEC is defined as follows.
Regarding the effect index value obtained in the biological response test, the lowest test concentration at which a statistically significant decrease was observed compared to the control group (blank, test concentration 0%), the lowest effect concentration (LOEC), The next lower test concentration is taken as the maximum no effect concentration (NOEC). The test concentration is 5 concentration groups (80%, 40%, 20%, 10% and 5% ) is the basis.
That is, a large NOEC (small TU) indicates that even if the sample (first treated water) is insufficiently diluted, the toxicity is small and the effect on organisms is small. On the other hand, a small NOEC (large TU) means that the sample (first treated water) must be diluted at a considerably large rate when discharged. At a dilution ratio of

In November 2015, the Ministry of the Environment published a report on the use of bioresponses in wastewater management methods (review committee report on water environment management methods using bioresponses), which states that evaluation of test results Under current wastewater regulations, when discharged water is discharged into public water areas, it is usually diluted by at least 10 times in public water areas that are a reasonable distance from the outlet due to the river water that flows there. Effluent standards are set at 10 times the environmental standards, in principle, based on the assumption that it will be , if the dilution ratio required to eliminate the toxicity of the wastewater exceeds 10 times (the toxicity of the wastewater does not become effective unless the wastewater is diluted to 10 times or more), i.e., the maximum no-effect concentration If the reciprocal TU (Toxic Unit = 100/NOEC) of NOEC (%) exceeds 10, it is assumed that the drainage needs to be improved."
Therefore, one example of criteria for evaluating that the first treated water needs to be improved in terms of toxicity is TU exceeding 10 as a result of the biological response test.

(Other embodiments)
In the wastewater treatment method of the present invention, an organic adsorbent is added to the first treated water obtained by treating the wastewater so as to satisfy the uniform wastewater standard to obtain the second treated water, and the second treated water is obtained. Any method may be used as long as it separates water from the organic adsorbent into solid and liquid, and is not limited to the method using the illustrated waste water treatment apparatus.
For example, one or both of the addition of the metal adsorbent and the addition of the flocculant may be omitted.
Adjustment of the pH of the second treated water containing the organic matter adsorbent in the membrane separation device 14 may be omitted.

(Mechanism of action)
In the wastewater treatment method of the present invention described above, an organic adsorbent is added to the first treated water obtained by treating the wastewater so as to satisfy the uniform wastewater standards to obtain the second treated water. Since the second treated water and the organic matter adsorbent are solid-liquid separated, the organic matter in the first treated water is adsorbed by the organic matter adsorbent, and the second treated water in which the organic matter is reduced is obtained. . In addition, the metal elements in the first treated water are also adsorbed by the organic matter adsorbent to obtain the second treated water in which the metal elements are reduced. As a result, treated water in which various toxic factors affecting organisms are reduced can be obtained.

Further, a biological response test is performed on a sample collected from the first treated water, and if it is evaluated that the toxicity needs to be improved, an organic adsorbent is added to the first treated water. The amount of organic adsorbent used can be saved, and treated water in which various toxic factors affecting living organisms are reduced can be obtained at low cost.
In addition, if a flocculant is added to the second treated water containing the organic matter adsorbent, it can be expected to improve the efficiency of solid-liquid separation and improve the water quality of the treated water. In addition, the effect of removing biologically influential substances derived from suspended solids that could not be adsorbed by organic adsorbents and metal adsorbents can be expected.
Further, if a metal adsorbent is further added to the first treated water, a second treated water in which the metal elements are further reduced can be obtained.

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

(Analysis of treated water)
The pH, TOC concentration, and metal element (aluminum, cadmium, iron, zinc) concentration of the samples (first treated water and second treated water) were measured in accordance with JIS K 0102: 2013 "Factory wastewater test method". bottom.

(Biological response test)
As a biological response test, the Ministry of the Environment announced in March 2013 "Effluent test method using biological response (study plan)""Short-term toxicity test method using embryonic and larval stage fish" Daphnia reproduction test method using Daphnia” and “Growth inhibition test method using freshwater algae” were adopted.

(Short-term toxicity test method using embryonic and larval stage fish)
Zebrafish (Danio rerio) embryos (fertilized eggs) within 4 hours after fertilization were used in the test.
Tap water dechlorinated with activated carbon was used as test water. The pH was 6.5 to 8.5, and the dissolved oxygen was 80% or more of the saturated oxygen concentration.
A test solution was prepared by diluting a sample (first treated water or second treated water) with test water for each test concentration. The test concentration (concentration of the sample in the test solution) was five concentrations (80%, 40%, 20%, 10% and 5%) with a common ratio of 2 for the dilution ratio. Test water was used as the test solution for the control plot (blank, test concentration 0%).

The test conditions were as follows.
・Exposure method: semi-static method (change water every 2 days).
・Exposure period: From the day when more than 50% of the embryos (fertilized eggs) hatched in the control plot until 5 days later (in the case of zebrafish, 8 to 10 days from the start of exposure).
• Number of repetitions: 4 containers per concentration zone.
- Number of eggs tested: 15 eggs per container.
• Amount of test solution: 50 mL/container.
• Test temperature: 26±1°C.
・Lighting: 16 hours light period, 8 hours dark period with room light.
・Feeding: None.
・Ventilation: None.

Every 24 hours from the start of exposure, test organisms were observed in all test containers and the number of live, dead and hatched embryos was recorded.
After completion of the test, the effectiveness of the test was judged from the following conditions.
・The hatching rate in the control plot should be 80% or more.
- The survival rate at the end of exposure in the control group should be 70% or more.
・Dissolved oxygen in the control group should be 60% or more of the saturated oxygen concentration throughout the exposure period.

Based on the data obtained from the test, the hatching rate, post-hatch survival rate, Viability and survival indices were calculated for each test vessel.
The effect index values (hatch rate, post-hatch survival rate, survival rate, or survival index) were subjected to the statistical analysis described below to determine the NOEC.
TU (=100/NOEC) was calculated. When TU exceeded 10, the sample (first treated water or second treated water) was evaluated as needing improvement in toxicity.

(Daphnia reproduction test method using Cicada flea)
Ceriodaphnia dubia was used for the test.
Tap water dechlorinated with activated carbon was used as test water. The water temperature was adjusted to 25±1° C. so that the dissolved oxygen was 90-100% of the saturated oxygen concentration.
A test solution was prepared by diluting a sample (first treated water or second treated water) with test water for each test concentration. The test concentration (concentration of the sample in the test solution) was five concentrations (80%, 40%, 20%, 10% and 5%) with a common ratio of 2 for the dilution ratio. Test water was used as the test solution for the control plot (blank, test concentration 0%).

The test conditions were as follows.
・Exposure method: semi-static method (change water every 2 days).
・Exposure period: Up to 8 days (until 60% or more of the individuals in the control group give birth to 3 litters or more).
- Number of repetitions: 10 containers per concentration zone.
- Number of test organisms: 10 individuals per concentration zone (1 individual per container).
- Amount of test solution: 15 mL/container.
• Test temperature: 25±1°C.
・Lighting: 16 hours light period, 8 hours dark period with room light.
Feed: Appropriate amounts of YCT and unicellular green algae were provided daily. As a guideline, the feeding amount was 50 μL of YCT and 0.02 to 0.05 mgC of algae concentrate in terms of organic carbon per individual per day.

From a series of single cultures (individually reared), 10 rearing containers containing ten individuals were prepared. The larvae of the same litter born from the same parent individual were transferred one by one from one breeding container to the test container for the control group and each concentration group. Similarly, larvae were put from each breeding container (remaining 9) into the control group and the test container (remaining 9 each) of each concentration group. This time point was taken as the beginning of exposure.
Every day, the life and death of the test individual (parent individual) was observed and the larvae born were counted for each test container.
After the daily operation was completed, the number of litters in the control group was counted, and the test was terminated on the day when 60% or more of the test individuals were confirmed to have 3 litters or more. However, the maximum exposure period was 8 days.
After completion of the test, the effectiveness of the test was judged from the following conditions.
・The mortality rate of the parental individuals in the control group should be 20% or less.
・At least 60% of the test individuals in the control group should give birth to 3 offspring in a maximum of 8 days.
・The total number of litters for 3 litters in the control group should be 15 or more on average.
・The production of dormant eggs should not be confirmed in the control group.

When 60% or more of the test individuals in the control group gave birth to 3 litters, the number of litters of 3 litters was counted for each test vessel in the concentration group, and the average value was calculated for each concentration group.
The effect index value (number of offspring) was subjected to statistical analysis to be described later, and NOEC was determined.
TU (=100/NOEC) was calculated. When TU exceeded 10, the sample (first treated water or second treated water) was evaluated as needing improvement in toxicity.

(Growth inhibition test method using freshwater algae)
Muremikazukimo (Pseudokirchneriella subcapitata) was used for the test.
As a medium, an OECD medium indicated in OECD Test Guideline 201 was used.
A test solution was prepared by diluting a sample (first treated water or second treated water) with a medium for each test concentration. The test concentration (concentration of the sample in the test solution) was five concentrations (80%, 40%, 20%, 10% and 5%) with a common ratio of 2 for the dilution ratio. A culture medium was used as the test solution for the control group (blank, test concentration 0%).

The test conditions were as follows.
・Exposure method: static type, shaking culture (100 rpm).
• Duration of exposure: 72 hours.
• Number of repetitions: 3 containers per concentration zone. Six containers were used for the control section.
- Initial biomass: ⁵ x 103 cells/mL.
- Amount of test solution: 100 mL/container.
• Test temperature: 22±2°C.
- Illumination: fluorescent lamp light, 24-hour light period, light intensity of 65 to 75 μmol/m ² /s near the liquid surface in the test container.

The biomass of the precultured test algae is measured, and a predetermined amount of the preculture solution (algae suspension) is added to each test vessel so that the initial biomass in the test solution is 5 × 10 ³ cells / mL. added to the test solution. After 24, 48 and 72 hours of exposure (end of exposure), aliquots of test solution were removed from each test container and biomass was determined using a particle counter.
After completion of the test, the effectiveness of the test was judged from the following conditions.
• At least a 16-fold increase in control biomass during the exposure period.
• The coefficient of variation (mean value) of daily growth rate in control plots should not exceed 35% throughout the exposure period.
• The coefficient of variation of growth rate between repetitions in the control plot should not exceed 7%.

For the control group and each concentration group, the growth rate from the start of exposure to the end of exposure was calculated according to "4.6.1 Calculation of growth rate" of "Effluent test method using biological response (study plan)". Calculated by the method described.
For each concentration group and each container, the growth inhibition rate (I _μ ) was calculated by the following formula based on the average value of the growth rate of the control group (μ _c ) and the growth rate of each concentration group (μ _t ).
I _μ = (μ _c −μ _t )/μ _c ×100
The effect index value (growth rate from the start of exposure to the end of exposure) was subjected to the statistical analysis described below to determine the NOEC.
TU (=100/NOEC) was calculated. When TU exceeded 10, the sample (first treated water or second treated water) was evaluated as needing improvement in toxicity.

(Determination of NOEC by statistical analysis)
A significance test was performed on the influence index values obtained in the biological response test. A significant difference test was performed by the multiple comparison method comparing the control group and multiple concentration groups. The analysis procedure was as follows. The significance level in each test was set at 5%, and a one-sided test was assumed.
(i) The homoscedasticity of the test section (including the control section) was tested by Bartlett's test.
(ii) When homoscedasticity was observed in (i) above, it was tested whether there was a significant difference within the test interval by a parametric one-way analysis of variance (ANOVA).
(iii) When a significant difference is observed in (ii) above, the significant difference between the control group and the concentration section is tested by Dunnett's multiple comparison test, and the lowest concentration section in which a significant difference is observed is the lowest effect concentration (LOEC). , and the concentration zone one level lower than that was defined as the maximum no-effect concentration (NOEC). When no significant difference was observed in (ii) above or in the multiple comparison test, the NOEC was taken as the highest concentration group or higher.
(iv) When the homoscedasticity was not observed in (i) above, the data were transformed (Arcsine transformation for ratio data, Log transformation for continuous data) and the homoscedasticity was tested again. When homodispersity was observed, the above (ii) was carried out.
(v) When a significant difference was observed in (iv) above, a non-parametric Kruskal-Wallis rank sum test was performed to test whether there was a significant difference within the test interval.
(vi) When a significant difference is observed in (v) above, the significant difference between the control section and the concentration section is tested by Steel's multiple comparison test, and the lowest concentration section in which a significant difference is observed is LOEC, one lower. The concentration group of was designated as NOEC. (iv) or when no significant difference was observed in the multiple comparison test, the NOEC was defined as the highest concentration group or higher.

(Comparative example 1)
A first treated water was prepared by treating waste water from a pharmaceutical factory so as to meet uniform waste water standards.
Table 1 shows the analysis results of the first treated water and the results of the biological response test using the first treated water. Table 2 shows the growth inhibition rate in the "growth inhibition test method using freshwater algae".

(Comparative example 2)
A 1 L polypropylene container was charged with 700 mL of the first treated water. 100 mg of a flocculant (polyaluminum chloride) was added to the first treated water. The temperature of the first treated water in the container was adjusted to 25° C., the pH of the first treated water was adjusted to between 6.5 and 7.5, and the mixture was stirred at a stirring speed of 140 rpm for 2 hours. After standing for 30 minutes, solid-liquid separation was performed by sedimentation. The supernatant was filtered through a filter (pore size 0.22 μm) to obtain a filtrate (second treated water).
Table 2 shows the analysis results of the second treated water and the results of the biological response test using the second treated water. In addition, in the biological response test using the first treated water of Comparative Example 1, it was evaluated that it was necessary to improve toxicity only with the "growth inhibition test method using freshwater algae". In the biological response test using the treated water, only the "growth inhibition test method using freshwater algae" was performed, and only the growth inhibition rate was obtained.

(Example 1)
A 1 L polypropylene container was charged with 700 mL of the first treated water. 70 g of powdered activated carbon was added to the first treated water. The temperature of the first treated water in the container was adjusted to 25° C., the pH of the first treated water was adjusted to between 6.5 and 7.5, and the mixture was stirred at a stirring speed of 140 rpm for 2 hours. After standing for 30 minutes, solid-liquid separation was performed by sedimentation. The supernatant was filtered through a filter (pore size 0.22 μm) to obtain a filtrate (second treated water).
Table 2 shows the analysis results of the second treated water and the results of the biological response test using the second treated water. In addition, in the biological response test using the first treated water of Comparative Example 1, it was evaluated that there was a need to improve toxicity only by the "growth inhibition test method using freshwater algae". In the biological response test using the treated water, only the "growth inhibition test method using freshwater algae" was performed, and only the growth inhibition rate was obtained.

A reduction in TOC and metallic elements was observed with the addition of flocculants or activated carbon. In addition, a reduction in growth inhibition rate was also confirmed. In particular, it was found that the addition of activated charcoal has a high reduction effect. From these results, various toxic factors that affect living organisms are reduced by adding activated carbon to the first treated water obtained by treating the wastewater so as to satisfy the uniform wastewater standards. It was found that the treated water can be obtained with

The wastewater treatment method of the present invention was obtained by treating wastewater so as to satisfy the uniform wastewater standards, but as a result of conducting a biological response test, the first treated water was evaluated as needing to be improved in terms of toxicity. It is useful as a reprocessing method.

10 primary treatment means,
12 adsorption treatment tank,
14 membrane separator,
16 coagulation sedimentation tank,
18 reservoir,
20 means for adding organic adsorbent,
22 metal adsorbent addition means,
24 flocculant addition means,
26 pH adjusting means,
30 drainage introduction line,
32 first treated water transfer line,
34 second treated water transfer line,
36 supernatant liquid transfer line,
38 tank body,
40 water tanks,
42 membrane modules,
44 permeate transfer line,
46 vacuum pump,
48 air diffuser,
50 Blower,
52 air line,
54 floc extraction line,
56 floc extraction valve,
60 organic matter adsorbent storage tank,
62 organic adsorbent supply line,
64 pumps,
66 metal adsorbent reservoir,
68 metal adsorbent supply line,
70 pump,
72 coagulant reservoir,
74 flocculant supply line,
76 pump,
78 acid reservoir,
80 acid supply line,
82 pump,
84 alkali reservoir,
86 alkali supply line,
88 pump,
90 pH measuring device,
92 controller,
94 tank body,
96 floc extraction line,
98 Flock extraction valve.

Claims (10)

An organic adsorbent is added to the first treated water obtained by treating the wastewater so as to satisfy the uniform wastewater standard to obtain a mixture containing the second treated water and the organic adsorbent,
A waste water treatment method for solid-liquid separation of the mixture into the second treated water and the organic adsorbent,
A biological response test is performed on the sample collected from the first treated water, and when it is evaluated that the toxicity needs to be improved, the organic matter adsorbent is added to the first treated water, and the organic matter A waste water treatment method , wherein the amount of adsorbent to be added is adjusted based on information on at least one of the TOC concentration and the metal element concentration of the first treated water .
However, the uniform effluent standard is the effluent standard stipulated in the Prime Minister's Office Ordinance (Prime Minister's Office Ordinance No. 35 of 1971) that stipulates effluent standards based on the provisions of Article 3, Paragraph 1 of the Water Pollution Control Law. .
In addition, the biological response test was organized by the "Study Group on Water Environment Management Techniques Using Biological Responses" established by the Ministry of the Environment, and was published by the Ministry of the Environment in December 2017. In the current summary of technical matters of evaluation and management (improvement) methods (as of the end of November 2017), "Evaluate the toxicity of chemical substances by confirming (using) the response of organisms to chemical substances. defined as “test”. 2. The wastewater treatment method according to claim 1, wherein solid-liquid separation by a membrane or solid-liquid separation by sedimentation is used as the solid-liquid separation. 3. The wastewater treatment method according to claim 1, wherein a coagulant is added to said second treated water containing said organic matter adsorbent. The wastewater treatment method according to any one of claims 1 to 3 , wherein the organic adsorbent contains powdered activated carbon. The wastewater treatment method according to any one of claims 1 to 4 , further comprising adding a metal adsorbent to the first treated water. The wastewater treatment method according to claim 5 , wherein a cation exchange resin or a chelate resin is used as the metal adsorbent. A primary treatment means for treating wastewater to obtain a first treated water so as to satisfy uniform wastewater standards;
an adsorption treatment tank for treating the first treated water with an organic adsorbent to obtain a second treated water;
organic adsorbent addition means for adding the organic adsorbent to the first treated water;
Solid-liquid separation means for solid-liquid separation between the second treated water and the organic adsorbent ,
The organic matter adsorbent addition means performs a biological response test on the sample collected from the first treated water, and if the toxicity is evaluated as needing to be improved, the organic matter adsorbs to the first treated water. Add agent,
Further, the amount of the organic adsorbent added to the first treated water by the organic adsorbent adding means is determined based on at least one of the TOC concentration and the metal element concentration of the first treated water. wastewater treatment system with a control system that regulates
However, the uniform effluent standard is the effluent standard stipulated in the Prime Minister's Office Ordinance (Prime Minister's Office Ordinance No. 35 of 1971) that stipulates effluent standards based on the provisions of Article 3, Paragraph 1 of the Water Pollution Control Law. .
In addition, the biological response test was organized by the "Study Group on Water Environment Management Techniques Using Biological Responses" established by the Ministry of the Environment, and was published by the Ministry of the Environment in December 2017. In the current summary of technical matters of evaluation and management (improvement) methods (as of the end of November 2017), "Evaluate the toxicity of chemical substances by confirming (using) the response of organisms to chemical substances. defined as “test”. The waste water treatment apparatus according to claim 7 , wherein said solid-liquid separation means is a membrane separator or a coagulating sedimentation tank. 9. A waste water treatment apparatus according to claim 7 , further comprising a flocculant adding means for adding a flocculant to said second treated water containing said organic matter adsorbent. The waste water treatment apparatus according to any one of claims 7 to 9 , further comprising metal adsorbent adding means for adding a metal adsorbent to said first treated water .

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