WO2015110091A1 - System and method for purifying waste water using powdered activated carbon - Google Patents

Abstract

A system for purifying waste water using powdered activated carbon, comprising a carbon-adding device, a mixing and treating device, a carbon-water separation device, a backwashing device, a control system, and a power module. Also disclosed is a method for purifying waste water using powdered activated carbon. In the method, powdered activated carbon and waste water are fully mixed and delivered using a feeding pump (306) into the carbon-water separation device for carbon-water separation. According to the difference between the water intake pressure and the water discharge pressure of the carbon-water separation device detected by a pressure controller (404), the backwashing device is automatically activated to backwash a hollow, microporous filter pipe (302). The backwashing device is turned off, and a solenoid valve (304) at the carbon slurry outlet is turned on for carbon slurry removal, dehydration, drying, and re-activation. The system and method use simple, easily operable equipment at a low operation cost. Separated powdered activated carbon is collected and recycled. Equipment has long continuous operation capacity, and backwashing is efficient.

Description

System and method for purifying sewage by using powdered activated carbon Technical field

 The invention belongs to the technical field of environmental protection, and relates to a system and a method for purifying sewage by using powdered activated carbon.

 Background technique

Powdered activated carbon purification technology has been used to treat water for 70 years. From the first application of powdered activated carbon in the United States to eliminate the odor of chlorophenol, the effective way to remove impurities in water is still activated carbon purification technology. The effect has been approved by many countries.

Activated carbon can be classified into powdered activated carbon or granular activated carbon according to its appearance. Generally, more than 90% of the activated carbon passing through the 80 mesh standard sieve or the activated carbon having a particle size of less than 0.175 mm is generally referred to as powdered activated carbon or powdered carbon, and the activated carbon having a particle size of more than 0.175 mm is referred to as granular activated carbon. With the advancement of separation technology and the emergence of certain application requirements, the particle size of powdered carbon tends to become more and more refined, and some occasions have reached micron or even nanometer scale. Activated carbon is a kind of micro-quality carbon material made of carbon-containing material with black appearance, developed internal pore structure, large surface area and strong adsorption capacity. As a low-cost adsorbent with large surface area and strong adsorption capacity, activated carbon is widely used in urban sewage, advanced treatment of industrial wastewater and purification of polluted water sources.

The adsorption of solute molecules in water by powdered activated carbon is a complex process and is the result of several forces acting together, including ion attraction, van der Waals forces, chemical impurities and forces. After adding powdered activated carbon, a considerable part of the organic matter in the water body is removed, the content of the gelatinous substance in the water body is reduced, and the surface viscosity is decreased. The adsorption of powdered activated carbon on floc is beneficial to the bridging of flocs and can improve the structure of flocs. Therefore, for water bodies with low turbidity and serious pollution, the addition of powdered activated carbon has good ability to remove organic pollution. The effluent water quality has been greatly improved, which is a relatively small investment and quick effect, especially for the large-scale old water plant, which is a reliable purification process.

Granular activated carbon is expensive, can be reused after regeneration, and is easy to operate and manage. Therefore, it is currently used in water treatment. Compared with granular activated carbon, powdered activated carbon is easy to prepare, relatively low in price, strong in adsorption capacity, fast in adsorption speed, and sufficient in adsorption capacity, but requires a proprietary separation method, and the cost of regeneration is high.

 Summary of the invention

 In order to solve the above technical problems, the present invention provides an inexpensive and highly efficient system and method for purifying sewage using powdered activated carbon.

The technical scheme adopted by the system of the present invention is: a system for purifying sewage by using powdered activated carbon, comprising: a carbon adding device, a mixing processing device, a carbon water separating device, a backwashing device, a control system and a power module;

The carbonizing device includes a receiving hopper, a variable speed motor, a screw conveying shaft, a fixing sleeve, a rubber tube, and the fixing sleeve is sleeved on the screw conveying shaft, and one end of the rubber tube is The screw conveying shaft is connected, the other end is inserted into the mixing processing device, the receiving hopper outlet is connected with the screw conveying shaft, and the rotating shaft of the variable speed motor is a screw conveying shaft connection for driving the screw conveying axial direction of the feeding device in the mixing processing device;

The mixing treatment device comprises a stirring mixing tank, a stirring motor and a stirring paddle, wherein the stirring motor is fixedly mounted on the mixing mixing tank, and a rotating shaft extends into the mixing mixing tank, and the stirring paddle is fixedly installed. On the rotating shaft of the stirring motor, the mixture is stirred and stirred in the mixing tank to achieve sufficient mixing of the charcoal water;

The carbon water separation device comprises a cylindrical filter, a hollow microporous filter tube, a carbon water separation device feed electromagnetic valve, a carbon slurry outlet electromagnetic valve and a clean water outlet electromagnetic valve, and the top of the cylindrical filter is advanced a feed port is connected to the bottom discharge port of the agitating mixing tank through the carbon water separator feeding solenoid valve, and the hollow microporous filter tube is disposed in the cylindrical filter, the The bottom of the cylindrical filter is respectively provided with a carbon slurry outlet and a clean water outlet, and the carbon slurry outlet and the purified water outlet are respectively provided with a carbon slurry outlet electromagnetic valve and a clean water outlet electromagnetic valve;

The backwashing device comprises an air compressor, a backwash pump, a backwash water tank, a backwash water solenoid valve, a backwash gas water solenoid valve and a flushing nozzle, the air compressor and the backwash water tank The air inlet is connected, the backwashing pump is connected to the water inlet of the backwash water tank through the backwash water solenoid valve, and the water outlet of the backwash water tank is electromagnetically passed through the backwash water a valve is connected to the rinsing nozzle, and the rinsing nozzle is disposed in the cylindrical filter and can move up and down in the hollow microporous filter tube;

The power module is connected to the control system, and the control system is respectively coupled with the variable speed motor, the agitating motor, the carbon water separating device feeding electromagnetic valve, the carbon slurry outlet electromagnetic valve, the water purifying water electromagnetic a valve, an air compressor, a backwash pump, a backwash water solenoid valve, a backwash gas water solenoid valve and a flushing nozzle are connected for controlling the variable speed motor, the stirring motor, the carbon water separating device feeding solenoid valve, Carbon slurry outlet solenoid valve, clean water outlet solenoid valve, air compressor, backwash pump, backwash water solenoid valve, backwash gas water solenoid valve and flushing nozzle work.

Preferably, the carbon water separation device further comprises a feed pump connected to the control system and disposed at a bottom discharge port of the agitation mixing tank for conveying to the carbon water separation device A mixture of charcoal and water.

Preferably, the backwashing device further comprises a pressure controller connected to the control system and disposed on the backwash water tank for detecting a difference in pressure between the inlet and outlet of the carbon water separation device.

 Preferably, the hollow microporous filter tubes are at least one set, and the plum core type is disposed in the cylindrical filter.

 Preferably, the hollow microporous filter tube is a PA tube.

 Preferably, the hollow microporous filter tube is a stainless steel tube.

 Preferably, the hollow microporous filter tube is sleeved with a filter layer.

 Preferably, the filter layer is a precision filter layer formed by winding a polyethylene wire.

 Preferably, the rubber tube is a bendable lining steel wire rubber tube.

 The technical solution adopted by the method of the invention is: a method for purifying sewage by using powdered activated carbon, characterized in that it comprises the following steps:

 Step 1: injecting sewage into the mixing treatment device, and simultaneously adding powdered activated carbon to the mixing treatment device by using the carbonizing device;

Step 2: Turn off the carbon adding device, start the stirring motor, and drive the stirring paddle to stir, so that the powdered activated carbon and the sewage are thoroughly mixed uniformly;

Step 3: The charcoal water mixture is sent to the carbon water separation device by using the feed pump to perform carbon water separation, and the carbon water mixture liquid is separated and separated by the outer diameter of the hollow microporous filter tube. Passing through the micropores of the hollow microporous filter tube into the inner diameter of the hollow microporous filter tube to concentrate the water, and the powdered activated carbon is trapped in the cylindrical filter;

Step 4: starting the backwashing device, and backwashing the hollow microporous filter tube by self-starting the backwashing device according to the pressure difference between the inlet and outlet of the carbon water separation device detected by the pressure controller;

 Step 5: Close the backwashing device, open the carbon slurry outlet solenoid valve, remove the carbon slurry, prepare to dehydrate, dry and then activate.

Preferably, the sewage is injected into the mixing treatment device as described in the step 1, and the powdered activated carbon is added to the mixing treatment device by the carbonizing device, and the rubber tube is connected between the lower port and the liquid surface. The distance is maintained between 0.5 and 0.8 m, and the sewage flow rate is maintained between 0.3 m/s and 0.6 m/s.

Preferably, the carbon water separation is carried out as described in the step 3, wherein the filtration area to the effective volume ratio of the empty microporous filter tube is 0.3 to 0.9 m ² /m ³ .

 Preferably, the hollow microporous filter tube is backwashed as described in step 3, and the backwashing gas pressure is 0.06 to 0.09 MPa.

 Preferably, the carbon slurry is dewatered as described in step 3, and a plate and frame filter press is used.

The system and method adopted by the invention have the advantages of simple and easy operation of the powder activated carbon, low operation cost, centralized separation of the powdered activated carbon, long running time of the equipment, and short backwashing efficiency.

 DRAWINGS

 FIG. 1 is a system structural diagram of an embodiment of the present invention.

 2 is a flow chart of a method of an embodiment of the present invention.

 detailed description

The present technical solution is further described below in conjunction with the accompanying drawings, which are illustrated in the accompanying drawings, in which the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions, but the description only The invention is not to be construed as limiting the invention.

Please refer to FIG. 1 , the technical scheme adopted by the system of the present invention is: a system for purifying sewage by using powdered activated carbon, comprising a carbon adding device, a mixing processing device, a carbon water separating device, a backwashing device, a control system and a power module; The carbon adding device comprises a receiving hopper 101, a variable speed motor 102, a screw conveying shaft 103, a fixing sleeve 104, a bendable inner lining steel wire rubber tube 105, a fixing sleeve 104 sleeved on the screw conveying shaft 103, and a bendable lining One end of the steel wire rubber tube 105 is connected to the screw conveying shaft 103, and the other end is inserted into the mixing processing device. The receiving port of the hopper 101 is connected to the screw conveying shaft 103, and the rotating shaft of the variable speed motor 102 is connected with the screw conveying shaft 103 for The driving screw conveying shaft 103 feeds the mixing processing device. The mixing processing device includes a stirring mixing tank 201, a stirring motor 202 and a stirring paddle 203. The stirring motor 202 is fixedly mounted on the stirring mixing tank 201, and the rotating shaft extends into the mixing mixing tank 201. The stirring paddle 203 is fixedly mounted on the rotating shaft of the stirring motor 202 for stirring and mixing the mixed liquid in the mixing tank 201 to achieve thorough mixing of the charcoal water; The separation device includes a cylindrical filter 301, a hollow microporous filter 302, a carbon water separation device feed solenoid valve 303, a char slurry outlet solenoid valve 304, a purified water outlet solenoid valve 305, and a feed pump 306, and a cylindrical filter 301 The top feed inlet is connected to the bottom discharge port of the agitation mixing tank 201 through the carbon water separator feeding solenoid valve 303, and at least one set of hollow microporous filter tubes 302 are disposed in the cylindrical filter 301, hollow. The microporous filter tube 302 is externally provided with a precision filter layer formed by a polyethylene wire. The bottom of the cylindrical filter 301 is respectively provided with a carbon slurry outlet and a water outlet, and the carbon slurry outlet and the purified water outlet are respectively provided with carbon. a slurry outlet solenoid valve 304 and a clean water outlet solenoid valve 305, the feed pump 306 is disposed at the bottom discharge port of the agitation mixing tank 201 for conveying the charcoal water mixture to the carbon water separation device; the backwashing device includes an air compressor 401, a backwash pump 402, a backwash water tank 403, a pressure controller 404, a backwash water solenoid valve 405, a backwash gas water solenoid valve 406, and a flushing nozzle, and the air compressor 401 is connected to the backwash water tank 403 air inlet. Backwash pump 402 is backwashed by hydropower The valve 405 is connected to the water inlet of the backwash water tank 403, and the water outlet of the backwash water tank 403 is connected to the flushing nozzle through the backwashing gas water solenoid valve 406. The flushing nozzle is disposed in the cylindrical filter 301, and can be in the hollow microporous filter tube. The pressure controller 404 is disposed on the backwash water tank 403 for detecting the difference between the inlet and outlet water of the carbon water separation device; the power module is connected to the control system, and the control system is respectively connected to the variable speed motor 102 and the stirring motor 202. Carbon water separation device feed solenoid valve 303, carbon slurry outlet solenoid valve 304, water purification water outlet solenoid valve 305, feed pump 306, air compressor 401, backwash pump 402, pressure controller 404, backwash water solenoid valve 405. The backwashing gas water solenoid valve 406 is connected to the flushing nozzle for controlling the variable speed motor 102, the stirring motor 202, the carbon water separating device feeding solenoid valve 303, the carbon slurry outlet solenoid valve 304, and the water purifying water solenoid valve 305. The feed pump 306, the air compressor 401, the backwash pump 402, the pressure controller 404, the backwash water solenoid valve 405, the backwash gas water solenoid valve 406, and the flushing nozzle operate.

The hollow microporous filter tube 302 of the present embodiment is a PA tube. However, this is not a limitation on the material of the hollow microporous filter tube 302 of the present invention. In fact, the hollow microporous filter tube 302 of the present invention may be made of a stainless steel tube material or may be made of other materials as needed.

 Please refer to FIG. 2, the technical solution adopted by the method of the present invention is: a method for purifying sewage by using powdered activated carbon, comprising the following steps:

Step 1: injecting sewage into the mixing treatment device, and simultaneously adding powdered activated carbon to the mixing treatment device by using a carbon adding device; wherein, the sewage is injected into the mixing treatment device, and the powdered activated carbon is added to the mixing treatment device by using the carbon adding device, The distance between the lower port of the rubber tube 105 and the liquid surface is maintained between 0.5 and 0.8 m, and the flow rate of the sewage is maintained at 0.3 m/s to 0.6 m/s.

 Step 2: Turn off the carbon adding device, start the stirring motor 202, and drive the stirring paddle 203 to stir, so that the powdered activated carbon and the sewage are thoroughly mixed uniformly;

Step 3: The charcoal water mixture is sent to the carbon water separation device by the feed pump 306 for carbon water separation, and the carbon water mixture liquid is separated by the outer diameter of the hollow microporous filter tube 302, and the water passes through the hollow microporous filter tube. The micropores of the tube wall of 302 enter the inner diameter of the hollow microporous filter tube 302 to concentrate the water, and the powdered activated carbon is trapped in the cylindrical filter 301, wherein the filtration area to the effective volume ratio of the hollow microporous filter tube 302 is 0.3 to 0.9. m ² /m ³ . ;

Step 4: Start the backwashing device, according to the pressure difference between the inlet and outlet of the carbon water separation device detected by the pressure controller 404, and start the backwashing device to backwash the hollow microporous filter tube 302, and the backwashing pressure is 0.06 to 0.09 MPa;

 Step 5: Close the backwashing device, open the carbon slurry outlet solenoid valve 304, remove the carbon slurry, use a plate and frame filter press to dehydrate, and then activate after drying.

 The following are experiments and results of purifying sewage using the system and method.

 Experiment 1:

 1 100 kg of powdered activated carbon (particle size less than 0.175 mm) is put into the receiving hopper 101, and the variable speed motor 102 is adjusted to control the reasonable rotation speed, and the powdered activated carbon is sent to the stirring mixing tank 201 through the screw conveying shaft 103, and the powdered activated carbon is naturally dropped. On the sewage surface, the stirring motor 202 is started to promote the flow of water, the stirring time is set to 20 min, and then pumped into the cylindrical filter 301 by the feed pump 306, and a plurality of sets of hollow microporous filter tubes are arranged in the cylindrical filter 301. 302, separating the powdered activated carbon to form a filter layer, and the sewage is purified and then flows out from the clean water outlet solenoid valve 305.

 2 When the filtered purified water flow rate drops significantly (the water flow rate drops by 50%), the backflushing is required, the activated carbon layer in the cylindrical filter 301 is flushed out, and the carbon water separating device feed electromagnetic valve 303 and the clean water outlet electromagnetic valve 305 are closed. The backwash gas water solenoid valve 406 is opened, the back pressure is controlled to be 0.06 MPa, the air backlash time is 30 s, and the water is backflushed for 1 min. The carbon slurry is flushed out of the cylindrical filter 301 and enters the carbon slurry storage tank. The carbon slurry in the carbon slurry reservoir is driven into a plate and frame filter press, dehydrated by pressure filtration, and the carbon cake is recovered for regeneration.

 Among them, after backflushing, the backwashing effect is checked through the visual window, and then the backwashing device is shut down, and the carbon water mixture is repeatedly filtered.

 Example 2

1. Put 200kg of powdered activated carbon (particle size less than 0.175mm) into the receiving hopper 101, adjust the variable speed motor 102 to control the reasonable speed of 2~20r/min, and send the powdered activated carbon at a rate of 1kg/min through the screw conveying shaft 103 to the stirring. In the mixing tank 201, the activated carbon naturally falls on the water surface, the stirring motor 202 is started to promote the flow of water, the sewage flow rate is 60 to 1000 m ³ /h, the stirring time is set to 20 min, and then the cylindrical filter 301 is drawn by the feed pump 306. In the middle filtration, a plurality of sets of hollow microporous filter tubes 302 are arranged in the cylindrical filter 301, and the powdered activated carbon is separated to form a filter layer, and the sewage is purified and then flows out from the clean water outlet electromagnetic valve 305.

 2 When the flow rate of the filtered purified water drops significantly (the water flow rate drops by 40 to 70%), the backflushing is required, and the activated carbon layer in the cylindrical filter 301 is flushed out, and the carbon water separating device feed solenoid valve 303 and the clean water outlet electromagnetic valve are closed. 305, the backwashing gas water solenoid valve 406 is opened, the back pressure is controlled to be 0.08 MPa, the air backlash time is 30 to 60 s, the water is backflushed for 1 to 3 minutes, and the carbon slurry is punched out from the cylindrical filter 301 to enter the carbon slurry storage. Pool. The carbon slurry in the carbon slurry reservoir is driven into a plate and frame filter press, dehydrated by pressure filtration, and the carbon cake is recovered for regeneration.

 Among them, after backflushing, the backwashing effect is checked through the visual window, and then the backwashing device is shut down, and the carbon water mixture is repeatedly filtered.

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, any modifications, equivalents, improvements, etc. made within the spirit and principles of the present invention should be included in the present invention. Within the scope of protection of the invention.

Claims (14)

1. A system for purifying sewage by using powdered activated carbon, comprising: a carbon adding device, a mixing processing device, a carbon water separating device, a backwashing device, a control system and a power module;

   The carbon adding device comprises a receiving hopper (101), a variable speed motor (102), a screw conveying shaft (103), and a fixing sleeve (104). a rubber tube (105), the fixing sleeve (104) is sleeved on the screw conveying shaft (103), and one end of the rubber tube (105) and the screw conveying shaft (103) The other end of the hopper (101) is connected to the screw conveying shaft (103), and the variable speed motor (102) is connected to the mixing device. a rotating shaft coupled to the screw conveying shaft (103) for driving the screw conveying shaft (103) to feed the mixing processing device;

   The mixing processing device comprises a stirring mixing tank (201), a stirring motor (202) and a stirring paddle (203), the stirring motor (202) Fixedly mounted on the agitating mixing tank (201), the rotating shaft of which extends into the mixing mixing tank (201), and the stirring paddle (203) is fixedly mounted on the stirring motor (202) On the rotating shaft, used to stir the mixed liquid in the mixing tank (201) to achieve thorough mixing of the charcoal water;

   The carbon water separation device comprises a cylindrical filter (301), a hollow microporous filter (302), and a carbon water separation device feed solenoid valve (303) a carbon slurry outlet solenoid valve (304) and a clean water outlet solenoid valve (305), the top feed port of the cylindrical filter (301) is fed through the carbon water separator (301) Is connected to the bottom discharge port of the agitation mixing tank (201), and the hollow microporous filter tube (302) is disposed in the cylindrical filter (301), the cylindrical filter ( 301 The bottom is respectively provided with a carbon slurry outlet and a clean water outlet, and the carbon slurry outlet and the purified water outlet are respectively provided with a carbon slurry outlet electromagnetic valve (304) and a purified water outlet electromagnetic valve (305) );

   The backwashing device comprises an air compressor (401), a backwash pump (402), a backwash water tank (403), a backwash water solenoid valve (405 a backwash gas water solenoid valve (406) and a flushing nozzle, the air compressor (401) being connected to the inlet of the backwashing water tank (403), the backwashing pump (402) Passing the backwash water solenoid valve (405) to the water inlet of the backwash water tank (403), and the water outlet of the backwash water tank (403) passes through the backwash gas water solenoid valve ( 406 Connecting with the rinsing nozzle, the rinsing nozzle is disposed in the cylindrical filter (301), and can move up and down in the hollow microporous filter tube (302);

   The power module is connected to the control system, and the control system is respectively connected to the variable speed motor (102) and the stirring motor (202). ), carbon water separation device feed solenoid valve ( 303 ), carbon slurry outlet solenoid valve ( 304 ), clean water outlet solenoid valve ( 305 ), air compressor ( 401 ), backwash pump ( 402 ), a backwash water solenoid valve (405), a backwash gas water solenoid valve (406), and a flushing nozzle connection for controlling the variable speed motor (102) and the stirring motor (202) ), carbon water separation device feed solenoid valve ( 303 ), carbon slurry outlet solenoid valve ( 304 ), clean water outlet solenoid valve ( 305 ), air compressor ( 401 ), backwash pump ( 402 ), backwash water solenoid valve (405), backwash gas water solenoid valve (406) and flushing nozzle work.
2. A system for purifying sewage using powdered activated carbon according to claim 1, wherein said carbon water separating device further comprises a feed pump (306) And connected to the control system, disposed at the bottom discharge port of the agitation mixing tank (201) for conveying the carbon-water mixture to the carbon water separation device.
3. A system for purifying sewage using powdered activated carbon according to claim 1, wherein said backwashing device further comprises a pressure controller (404) And connected to the control system, disposed on the backwash water tank (403) for detecting the difference between the inlet and outlet water pressure of the carbon water separation device.
4. A system for purifying sewage using powdered activated carbon according to claim 1, wherein said hollow microporous filter tube (302) At least one set of plum cores is disposed within the cylindrical filter (301).
5. The system for purifying sewage by using powdered activated carbon according to claim 4, wherein the hollow microporous filter tube (302) is PA Tube.
6. A system for purifying sewage using powdered activated carbon according to claim 4, wherein said hollow microporous filter tube (302) ) is a stainless steel tube.
7. A system for purifying sewage using powdered activated carbon according to claim 1, 4, 5 or 6, characterized in that: said hollow microporous filter tube (302) The outer sleeve is provided with a filter layer.
8. According to claim 7 The system for purifying sewage by using powdered activated carbon is characterized in that the filter layer is a precision filter layer wound by a polyethylene wire.
9. A system for purifying sewage using powdered activated carbon according to claim 1, wherein said rubber tube (105) ) is a flexible inner lining wire rubber tube.
10. One use claim 1 The method for purifying sewage by using a system for purifying sewage by using a powdered activated carbon is characterized in that the method comprises the following steps:

    step 1 : injecting sewage into the mixing treatment device, and simultaneously applying powdered activated carbon to the mixing treatment device by using the carbonizing device;

    Step 2: Turn off the carbonizing device, start the stirring motor (202), and drive the stirring paddle (203 Agitation, promoting the powdered activated carbon and sewage fully mixed evenly;

    Step 3: The carbon water mixture is used to utilize the feed pump (306) Feeding into the carbon water separation device for carbon water separation, the carbon water mixed liquid is separated by the outer diameter of the hollow microporous filter tube (302), and water passes through the hollow microporous filter tube ( 302 The wall micropores enter the inner diameter of the hollow microporous filter tube (302) to concentrate the water, and the powdered activated carbon is trapped in the cylindrical filter (301);

    Step 4: Start the backwashing device according to the pressure controller (404 Detecting the difference between the inlet and outlet water pressure of the carbon water separation device, and self-starting the backwashing device to backwash the hollow microporous filter tube (302);

    Step 5: Close the backwashing device and open the carbon slurry outlet solenoid valve (304 ), the carbon slurry is removed, ready to be dehydrated, dried and then activated.
11. The method for purifying sewage by using powdered activated carbon according to claim 10, wherein: step 1 The sewage is injected into the mixing treatment device, and the powdered activated carbon is added to the mixing treatment device by the carbonizing device, and the distance between the lower port of the rubber tube (105) and the liquid surface is maintained. in Between 0.5 and 0.8 m, the sewage flow rate is maintained at 0.3 m/s to 0.6 m/s.
12. The method for purifying sewage by using a powdered activated carbon according to claim 10, wherein the carbon water separation is carried out in the step 3, wherein the filtration area to the effective volume ratio of the empty microporous filter tube (302) is 0.3 to 0.9. m ² /m ³ .
13. The method for purifying sewage by using a powdered activated carbon according to claim 10, wherein: said hollow microporous filter tube (302) described in step 3 ) Backwashing, the backwashing pressure is 0.06~0.09MPa.
14. The method for purifying sewage by using powdered activated carbon according to claim 10, wherein: step 5 The dewatering of the carbon slurry described in the above is a plate and frame filter press.