JPH11104679A - Cross-flow type wastewater treatment equipment - Google Patents

Abstract

(57) [abstract] (with correction) [PROBLEMS] In a cross flow type wastewater treatment system, a large amount of air is contained in the treated water, and the treated water discharged from the final treatment tank contains a filler and a turbid substance. Not to be. SOLUTION: A first processing tank I to which raw water is supplied and flows downward, a final processing tank III, and an intermediate processing tank II provided between the first processing tank and the final processing tank, The treatment tank is a cross-flow type wastewater treatment apparatus that supplies the treated water in the first treatment tank in a meandering manner in the vertical direction and supplies the treated water in a downward flow to the final treatment tank. Packed beds I 'and II' made of adhered activated carbon are provided, aeration devices 5 and 5 are provided in the first treatment tank and at least one intermediate treatment tank, and the packed beds are fluidized beds. A fixed bed III ′ made of activated carbon having a biofilm attached to a support thereof,
An activated carbon supply device 11 is provided, and a waste activated carbon extraction device 12 is provided in the first treatment tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering wastewater containing trace organic substances discharged from a semiconductor manufacturing process and a liquid crystal manufacturing process by treating the trace organic substances in the wastewater with a biofilm of oligotrophic bacteria attached to activated carbon particles. To a cross-flow type wastewater treatment apparatus.

[0002]

2. Description of the Related Art A cross-flow type wastewater treatment apparatus having a fluidized bed in which a biofilm is attached to activated carbon is conventionally known.

[0003]

In the conventional apparatus, a fluidized bed is provided in the final treatment tank, so that activated carbon may be mixed in the discharged treated water, and the treated water is removed by UF.
There is a problem that the membrane is clogged with activated carbon when treated with a membrane separation device using a membrane, an MF membrane or the like. Further, the amount of air is insufficient with respect to the ammonia in the raw water, and tens of ppm of ammonia cannot be nitrified.

[0004]

SUMMARY OF THE INVENTION The present invention has been developed to solve the above-mentioned problems of the conventional cross-flow type wastewater treatment apparatus, and comprises a first treatment tank to which raw water is supplied and which flows downward. , A final processing tank, and an intermediate processing tank provided between the first processing tank and the final processing tank.
This is a cross flow type wastewater treatment apparatus for supplying treated water in a treatment tank in a meandering manner in a vertical direction and supplying the treated water in a downward flow to a final treatment tank. The first treatment tank and the intermediate treatment tank are made of activated carbon having a biofilm attached thereto. In addition to providing a packed bed, an aerator that uses the packed bed as a fluidized bed is provided in the first treatment tank and at least one intermediate treatment tank, and the activated carbon having a biofilm adhered to a water-permeable support is provided in the final treatment tank. And a replenishing device for activated carbon, and a device for extracting waste activated carbon is provided in the first treatment tank.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In each of the illustrated embodiments, I represents a first treatment tank,
III is a final treatment tank, II is one or more odd number intermediate treatment tanks, and raw water is supplied from the supply pipe 1 to the first treatment tank and flows downward in the tank. In the first treatment tank and the intermediate treatment tank, packed layers I 'and II' of activated carbon having a biofilm attached are provided. Further, in the final treatment tank III, a packed layer III 'of activated carbon similarly having a biofilm attached thereto is provided on a support 2 such as gravel or a perforated plate. In the final treatment tank, a supply pipe 11 for new coal is provided, and in the first treatment tank, a pipe 12 for extracting waste coal such as a siphon pipe is provided.

The intermediate treatment tank II of the first embodiment shown in FIGS. 1 and 2 has one, and the partition wall 3 for separating the first treatment tank and the intermediate tank is separated from the bottom upward. The height of the partition wall 4 for separating the intermediate processing tank II and the final processing tank is the water surface W during operation.
Lower than 1. At the bottom of each of the tanks I, II, and III, a nozzle 5 for blasting air or cleaning water for aeration and cleaning is laid, and a common pipe 6 to which each nozzle 5 is connected has an air supply pipe. 7 and a water supply pipe 8 for washing water are connected via valves V1 and V2. When the valve V1 is opened and the valve V2 is closed, air is supplied to each nozzle 5, the V1 is closed and the valve V2 is closed.
When is opened, washing water is supplied to each nozzle 5. still,
A pipe connecting the nozzle 6 and the pipe 6 at the bottom of the final processing tank III is provided with a valve V3.

FIG. 1 shows an operation state of the first embodiment, in which a valve V
2 and V3 are closed and the valve V1 is opened to supply air to the nozzles 5 and 5 at the bottom of the first processing tank I and the intermediate processing tank II, and these nozzles 5 and 5 are used as aeration devices. Therefore, the activated carbon packed beds I ′ and I ′ in the first treatment tank I and the intermediate treatment tank II
I ′ becomes a fluidized bed whose bed height has been increased by bubbles rising in the tank, and the raw water supplied to the first treatment tank flows through the tank against bubbles rising in the fluidized bed of the packed bed I ′. Downflow. In this way, the raw water flowing downward in the tank comes into contact with the bubbles in a countercurrent manner, so that the raw water with the highest oxygen consumption on the raw water side has a high oxygen dissolving efficiency and is effective in the countercurrent method. Further, by performing aeration, the filter medium is in a fluid state, so that even if water is passed in a downward flow, clogging and drift of the filter medium do not occur.

The treated water that has reached the bottom of the first treatment tank I dives below the partition wall 3 and enters the bottom of the intermediate tank II. Upflow in the fluidized bed. The upper end of the partition wall 4 is lower than the water surface W1 during operation, but higher than the upper surface of the fluidized bed of the packed bed II whose bed height has been increased. It meanders from the upper end into the final treatment tank III, and flows downward in the tank. The treated water treated in the first treatment tank flows upward in the fluidized bed in the intermediate treatment tank II, and passes while contacting with the bubbles in the forward flow, so that the filter medium can be fluidized by the upward flow even with a small amount of air. There is a merit that can be achieved. In particular, since the water is once treated in the treatment tank I, the oxygen consumption of the inflow water in the tank II is reduced, and the air here can be improved by adding a necessary amount.

[0009] As described above, the aeration from the nozzle 5 causes a downward flow in the first treatment tank which is a fluidized bed.
By flowing upward in the intermediate treatment tank, a large amount of oxygen necessary for biological treatment is supplied to the treated water. Therefore, even if the ammonia concentration in the raw water is high, the ammonia can be completely nitrified.

As described above, air is not supplied to the nozzle 5 at the bottom of the final processing tank III. For this reason, the packed bed III 'of the activated carbon with the biofilm attached in the tank is a fixed bed. The filling layer III 'is provided on the support 2. Therefore, even if the treated water flowing downward in the final treatment tank contains activated carbon or turbidity flowing out of the intermediate treatment tank, the packed bed III ', which is a fixed bed, captures activated carbon or turbidity by filtration. In addition, the support 2 has an effect of preventing the III 'of the packed layer from falling to the lower part and providing a resistance for eliminating a drift at the time of back washing. Therefore, the treated water discharged from the bottom of the final treatment tank does not contain activated carbon or turbid matter. Therefore, even if the film is supplied to the film processing apparatus IV, there is no trouble to close the film.

The packed layers of the first treatment tank, the intermediate treatment tank, and the final treatment tank are made of activated carbon having a biofilm attached thereto. Also has the effect of adsorbing.

When the head loss of the packed bed III 'rises above a predetermined level, the packed bed in each of the tanks I, II, and III is washed, fresh coal (new activated carbon) is supplied to the final treatment tank III, and the first treatment is performed. Extraction of waste coal (activated carbon with reduced capacity) from tank I is performed in the following procedure.

First, as shown in FIG. 2A, the supply of raw water and the supply of air to the nozzles 5 of the first treatment tank and the intermediate treatment tank are stopped, and the two tanks I and II are allowed to stand still. The fluidized bed is restored to the height of the packed beds I 'and II'. Then, drain pipe 9
, And the water surface W2 in each tank is filled with the packed beds I ', II',
Drain the water until it is close to the top surface of III ′ (see FIG. 2B), and close the drain valve.

Thereafter, the valves V1, V3 are opened, air is blown out from the nozzle 5 at the bottom of each of the processing tanks I, II, III, and the packed layers I ', II', II are released by bubbles floating in each tank.
I ′ is developed, and air cleaning is performed to separate foreign matter and suspended matter captured by each packed bed from the activated carbon particles (see FIG. 2C). By performing air cleaning, the water surface W3 in each tank rises to just below the upper end of the partition wall 4. Then, as shown in FIG. 2 (D), the valve V1 is closed, the valve V2 is opened, and the washing water is spouted from the nozzle 5 at the bottom of each of the processing tanks I, II, III, and each of the packed layers I ', II'. , III 'are developed and washed with washing water.
The flush water discharge pipe 10 is opened and adjusted so that the flush water level W4 is slightly above the upper end of the partition wall 4. As a result, the foreign matter and turbid matter separated by the air cleaning are discharged together with the cleaning wastewater discharged from the discharge pipe 10.

During the washing with the washing water, replenishment of new coal slurry and extraction of waste coal are performed. The supply of the new coal slurry is performed by the supply pipe 11 in the final treatment tank. Packed bed developed in the final treatment tank by replenishing new coal slurry II
When the amount of activated carbon I ′ increases and its water level becomes higher than the upper end of the partition wall 4, the activated carbon of the packed bed III ′ flows across the partition wall 4 and flows into the intermediate treatment tank II together with water. In addition, the waste coal is extracted by a first extraction pipe 12 such as a siphon pipe.
The activated carbon of the packed bed I 'in the treatment tank is extracted together with the water in the tank, and the extracted activated carbon is collected in a container 13 and processed by a regeneration furnace or the like to regenerate. The activated carbon of the packed bed in the first treatment tank is extracted together with the water, and as the amount of water and activated carbon decreases, the water and activated carbon in the intermediate treatment tank move under the partition wall 3 into the first treatment tank. . Thus, by extracting waste coal from the first treatment tank and replenishing the final treatment tank with new charcoal, the activated carbon in the final treatment tank is moved to the intermediate treatment tank, and the activated carbon in the intermediate treatment tank is moved to the first treatment tank. Packed layers I ', II', I
The amount of activated carbon of II 'is harmonized without excess and deficiency.

The waste coal is extracted from the first treatment tank by extracting the activated carbon from the upper part of the packed bed I 'with reduced capacity, and the new charcoal is supplied to the bottom of the packed bed III' of the final treatment tank.
Activated carbon flowing into the intermediate treatment tank over the
Activated carbon on top of This is because the activated carbon having a reduced capacity is sequentially extracted from the activated carbon and the processing capacity of the entire apparatus can be stably maintained.

After washing with water, withdrawal of waste coal, and replenishment of new coal, after filling with water with washing water, etc.
After standing still as in (A) and sinking III ', the operation is resumed as shown in FIG.

FIG. 3 shows that an intermediate treatment tank between the first treatment tank I and the final treatment tank III has a first intermediate tank II-1, a second intermediate tank II-2, and a packed bed of activated carbon having a biofilm attached thereto. The operation is shown in the second embodiment in the case where three tanks, ie, the third intermediate tank II-3, are used. First treatment tank I, first intermediate tank II-1, second
Partition wall 3 that partitions intermediate tank II-2 and third intermediate tank II-3
Moves upward from the bottom, and the first intermediate tank II-1 and the second intermediate tank I
The height of the partition wall 4 that partitions the I-2, the third intermediate tank II-3 and the final treatment tank III is lower than the water surface W1 during operation. Therefore, during operation, the raw water supplied to the first treatment tank is processed by flowing downward in the tank, flows into the first intermediate tank from the bottom, flows upward, and then flows into the second intermediate tank from above. The water flows downward, and then flows into the third intermediate tank from the bottom and flows upward. Thus, while meandering in the vertical direction, the liquid finally flows into the final processing tank from above and flows downward.

At the bottom of each of the above-mentioned tanks, there are provided nozzles 5 for jetting air and washing water for aeration and washing. A common pipe 6 to which these nozzles 5 are connected is provided with a common pipe 6 as shown in FIG. Similarly, the air supply pipe 7 and the cleaning water supply pipe 8 are connected to the valves V1 and V2.
Are connected via. The nozzle of the first intermediate tank II-1, the nozzle of the third intermediate tank II-3, and the final processing tank II
A valve V3 is provided in a pipe connecting the nozzle I and the pipe 6.

In the operating state of FIG. 3, the valves V2 and V3 are closed,
The valve V1 is opened to supply air to the nozzles 5, 5 of the first processing tank I and the second intermediate tank II-2, and these nozzles 5, 5 are used as aeration devices. Thereby, the packed beds I 'and II-2' of the activated carbon in the first treatment tank I and the second intermediate tank II-2 become fluidized beds whose bed heights are increased by bubbles rising in the tank, and the first treatment tank I The raw water supplied to the tank and the treated water flowing from above into the second intermediate tank II-2 from the first intermediate tank float in the fluidized bed of the packed bed I 'and the fluidized bed of the packed bed II-2'. There is a merit that the filter medium is fluidized and the dissolving efficiency of oxygen is increased while flowing downward in response to the generated bubbles.

The treated water flowing upward in the first intermediate tank and the treated water flowing upward in the third intermediate tank are respectively filled with packed beds II-1 'and II-3 filled in the tanks. ', Which has the advantage that the filter medium can be fluidized by a water stream.

The first processing tank I and the second processing tank I
When aeration is performed on every other stage of the intermediate tank II-2 and denitrification assisting organic matter or raw water is supplied to the first intermediate tank II-2 and the third intermediate tank II-3, which are not aerated, by the supply pipe 14, Nitrification of ammonia by nitrifying bacteria in the first treatment tank I and the second intermediate tank II-2 NH ₄ + O ₂ → NO ₃ is performed, and the denitrification bacteria in the first intermediate tank II-1 and the third intermediate tank II-3. Denitrification NO ₃ → N ₂行 わ is performed.

As described above, air is not supplied to the nozzle 5 at the bottom of the final processing tank III. For this reason, the packed bed III 'of the activated carbon with the biofilm attached in the tank is a fixed bed. The filling layer III 'is provided on the support 2. Therefore, even if the treated water flowing downward in the final treatment tank contains activated carbon or turbidity flowing out from the third intermediate tank, the packed bed III ', which is a fixed bed, captures activated carbon or turbidity by a filtering action. In addition, the support 2 has an effect of preventing the III 'of the packed layer from falling to the lower part and providing a resistance for eliminating a drift at the time of back washing. Therefore, the treated water discharged from the bottom of the final treatment tank does not contain activated carbon or turbid matter. Therefore, even if the film is supplied to the film processing apparatus IV, there is no trouble to close the film.

The packed layers of the first treatment tank, the first, second and third intermediate tanks, and the final treatment tank are made of activated carbon having a biofilm attached thereto, so that efficient treatment with activated carbon having a large surface area can be achieved. At the same time, it has the effect of adsorbing organic matter that is difficult to treat.

When the head loss of the packed bed III 'rises above a predetermined level, each of the tanks I, II-1, II-2, II-3, I
The packed bed II is washed, new coal (new activated carbon) is supplied to the final treatment tank III, and waste carbon (activated carbon with reduced capacity) is extracted from the first treatment tank I. The procedure is exactly the same as that of the first embodiment described above, in which the supply of raw water and air is stopped as described in paragraph 0013, the water is drained after standing, and then all the tanks are described as described in paragraph 0014. Then, air is blown out from the nozzle 5 to perform air cleaning, and then cleaning water is blown out from the nozzles of all the tanks to perform cleaning. During the cleaning with the cleaning water, the cleaning water is injected into the final processing tank as described in paragraph 0015. New coal slurry is supplied by a supply pipe 11, and waste coal is extracted from the first treatment tank and extracted by a pipe 12. Thereby, a part of the activated carbon in the final treatment tank is in the third intermediate tank, a part of the activated carbon in the third intermediate tank is in the second intermediate tank, and a part of the activated carbon in the second intermediate tank is in the first intermediate tank. Part of the activated carbon in one intermediate tank is moved to the first treatment tank together with water, and the amount of activated carbon in each tank is adjusted to an appropriate amount.

Since the packed bed III 'of the final treatment tank III is a fixed bed, it cannot be aerated from below the support. However, as shown in FIG. 3, the air diffuser 15 is arranged above the packed bed III'. However, it is possible to make up for the shortage of air.

[0027]

According to the present invention, the first processing tank, the intermediate processing tank, and the final processing tank are arranged side by side, and while the apparatus is of a horizontal flow type, waste coal is extracted from the first processing tank and fresh coal is supplied to the final processing tank. Then, the activated carbon constituting the packed bed of each tank can be rationally moved similarly to the upper and lower multi-stage apparatus. In addition, since the bed of activated carbon in the final treatment tank is a fixed bed, even if activated carbon or turbidity flows into the treated water from the previous treatment tank and enters the treatment water, the fixed bed traps this by filtration, so the final bed The treated water from the treatment tank does not contain activated carbon or suspended matter. Therefore, no trouble occurs due to the outflow of activated carbon or suspended matter. In the first and second treatment tanks, aeration can be performed so that a large amount of dissolved oxygen can be contained in the treated water. Therefore, even if the raw water contains high-concentration ammonia, nitrification can be performed. Furthermore, by appropriately setting the tank to be aerated, denitrification can be performed in addition to nitrification.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an operation state of a first embodiment of a processing apparatus of the present invention.

FIG. 2A is an explanatory view of an operation stop state prior to the washing in the first embodiment, FIG. 2B is an explanatory view of a draining state of the first embodiment,
(C) is an explanatory view of a state of washing with air, and (D) is an explanatory view of a state where replenishment of new coal and extraction of waste coal are performed while washing with washing water.

FIG. 3 is an explanatory view of an operation state of a second embodiment of the processing apparatus of the present invention.

[Explanation of symbols]

 I First treatment tank I 'Filled layer of first treatment tank II Intermediate treatment tank II' Filled layer of intermediate treatment tank II-1 First intermediate tank II-2 Second intermediate tank II-3 Third intermediate tank III Final treatment Tank III 'Packing layer of final treatment tank 1 Raw water supply pipe 2 Support 3 Partition wall 4 Partition wall 5 Nozzle (aeration device) 7 Air supply pipe for aeration and cleaning air 8 Cleaning water supply pipe 9 Drainage Drainage pipe 10 Washing wastewater discharge pipe 11 New coal supply pipe 12 Waste coal extraction pipe

Claims (1)

[Claims] A first processing tank to which raw water is supplied and flowing downward; a final processing tank; and an intermediate processing tank provided between the first processing tank and the final processing tank. The tank is first
This is a cross flow type wastewater treatment apparatus for supplying treated water in a treatment tank in a meandering manner in a vertical direction and supplying the treated water in a downward flow to a final treatment tank. In addition to providing a packed bed, an aerator that uses the packed bed as a fluidized bed is provided in the first treatment tank and at least one intermediate treatment tank, and the activated carbon having a biofilm adhered to a water-permeable support is provided in the final treatment tank. A fixed bed comprising: a replenishing device for activated carbon; and a first treatment tank provided with a device for extracting waste activated carbon.