CN113415937A

CN113415937A - Oil field exploitation wastewater treatment equipment and method

Info

Publication number: CN113415937A
Application number: CN202110661869.0A
Authority: CN
Inventors: 吴俊峰; 吴玉辉
Original assignee: Yancheng Haideneng Water Treatment Environmental Protection Engineering Co ltd
Current assignee: Yancheng Haideneng Water Treatment Environmental Protection Engineering Co ltd
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-09-21

Abstract

The invention relates to the field of water treatment, and particularly discloses an oil field exploitation wastewater treatment device and a method, wherein the device comprises a wastewater tank, a demulsification air flotation oil removal device, a coagulation reaction device, a clarification concentration device, a multi-media filter, a stainless steel security filter and a sludge treatment device; the method of combining the demulsifier and the ultrasonic wave can better destroy a hydration film, enlarge oil droplets, and enable the oil droplets to be more easily absorbed by micro bubbles and float out of the water surface for removal, then treat the acid-base property of the oil extraction wastewater to ensure that the oil extraction wastewater is alkaline, calcium ions, magnesium ions and the like can react with each other to generate precipitates under the alkaline condition, and a coagulant is added into the wastewater, so that suspended matters of the wastewater are continuously aggregated by a flocculating agent to form the precipitates. Waste water after the flocculation gets into clarification enrichment facility, and the impurity in the waste water can very big be got rid of again through two kinds of different filters behind the supernatant fluid impurity removal through the swirler, reaches fine oil recovery waste water treatment effect.

Description

Oil field exploitation wastewater treatment equipment and method

Technical Field

The invention relates to the field of water treatment, in particular to an oil field exploitation wastewater treatment device and method.

Background

During oil production, the produced crude oil contains a large amount of moisture. The waste water from crude oil removal contains a large amount of petroleum pollutants, and high molecular oil recovery auxiliaries such as demulsifiers, surfactants and the like added in the oil recovery process, organic components of the high molecular oil recovery auxiliaries comprise alkanes, aromatic hydrocarbons, phenols, ketones, acids, halogenated hydrocarbons, nitrogen-containing compounds and the like, meanwhile, the waste water contains a large amount of inorganic salt anions and cations, and the oil field waste water has the characteristics of high salinity, more ions easy to scale, complex components and the like.

At present, the polymer-containing oil extraction wastewater is generally treated by a physical method or a chemical method at home and abroad; the physical method comprises the following steps: gravity precipitation, mechanical filtration, hydraulic cyclone, dosing coagulation air flotation, membrane technology and ultrasonic degradation technology; the chemical method comprises the following steps: chemical oxidation, electrochemical oxidation, photocatalytic oxidation, and the like. But the single physical method or chemical method has poor treatment effect on polymer-containing oil extraction wastewater, and the treated wastewater hardly reaches the safe discharge standard.

Disclosure of Invention

The invention solves the problems that: aiming at the problem of poor effect of treating the petroleum exploitation wastewater by a physical method or a chemical method in the prior art, the equipment and the method for treating the petroleum exploitation wastewater are provided.

The invention is realized by the following technical scheme that the equipment for treating the oil field exploitation wastewater comprises a wastewater tank, a demulsification air flotation oil removal device, a coagulation reaction device, a clarification concentration device, a multi-medium filter, a stainless steel security filter and a sludge treatment device;

the waste water tank, the demulsification air-flotation oil removal device, the coagulation reaction device, the clarification concentration device, the multi-medium filter and the stainless steel security filter are sequentially connected through pipelines;

a first lifting pump is arranged on a pipeline between the waste water tank and the demulsification air-flotation oil removal device;

a second lifting pump is arranged on a pipeline between the demulsification air-flotation oil removal device and the coagulation reaction device;

a third lifting pump is arranged on a pipeline between the coagulation reaction device and the clarification concentration device;

a clear water pump is arranged on a pipeline between the clarification concentration device and the multi-medium filter;

a clear water buffer tank is connected behind the stainless steel security filter through a pipeline, and a reinjection pump is installed on the clear water buffer tank through a pipeline;

the device is characterized in that a sludge outlet at the bottom of the clarification and concentration device is connected with a sludge treatment device through a pipeline, a sludge feeding pump is arranged between the pipelines, a filtrate outlet of the sludge treatment device is connected with an inlet of the clarification and concentration device through a pipeline, and a filtrate return pump is arranged on the pipeline.

Further, the demulsification air-flotation oil removal device comprises an air-flotation oil removal tank, a demulsifier dosing device, an ultrasonic transmitter, a bubble generator and a slag scraper;

the utility model discloses a demulsification device, including demulsification area, demulsifier, air supporting district, aeration board, bubble generator, still, the air supporting district is divided into broken breast district, air supporting district, the district that stews by two baffles, demulsification area and air supporting district lower part intercommunication, air supporting district and the district upper portion intercommunication that stews, broken breast portion is equipped with waste water entry and demulsifier and adds the medicine entry to be equipped with the filter screen layer of putting to one side, the filter screen layer below is equipped with multilayer "/" \\\ "alternating mixing baffle, can be to waste water and demulsifier rapid mixing, is equipped with a plurality of heating device between the mixing baffle, demulsification area bottom still is equipped with ultrasonic emitter, air supporting district bottom is equipped with the aeration board, the aeration board links to each other with bubble generator, it is equipped with scum scraper, guide swash plate and waste oil groove to stew the district top, and the waste liquid outlet is established and is being stood district side middle part position.

Further, the coagulation reaction device comprises a neutralization zone, a reaction zone and a flocculation zone which are connected in series, wherein two layers of partition plates are arranged between the neutralization zone, the reaction zone and the flocculation zone, so that waste liquid enters and exits from the bottom, an alkali dosing device, a PAC dosing device and a PAM dosing device are respectively arranged on the three zones, stirring devices are respectively arranged on the three zones, a scale inhibitor dosing device is further arranged on the flocculation zone, a pH detection device is further arranged in the neutralization zone, and the bottom of the flocculation zone is arranged at a waste water outlet of the coagulation reaction device.

Furthermore, a wastewater inlet pipeline of the clarification and concentration device extends below the liquid level, sludge sinks, supernatant liquid passes through the cofferdam and enters the clear water area, and an inlet pipeline of the clear water pump is arranged on the side surface of the clear water area.

Furthermore, a cyclone separator is arranged between the clean water pump and the multi-media filter, an upper water outlet of the cyclone separator is connected with the multi-media filter through a pipeline, and a lower water outlet of the cyclone separator returns to the clarification and concentration device through a pipeline.

Furthermore, the filter element of the stainless steel cartridge filter is PP melt-blown cloth.

Further, the sludge treatment device is a filter press.

In another aspect of the present invention, a method for treating wastewater from oil field exploitation is provided, which comprises the following steps:

conveying the wastewater from a wastewater tank to a demulsification air flotation oil removal device by a first lifting pump, and filtering by a filter screen layer to remove large-particle impurities;

secondly, the wastewater is heated by a heater in a demulsification area and is subjected to combined action of a chemical demulsifier and ultrasonic waves, so that emulsion stabilization conditions are eliminated, and the demulsification efficiency of the wastewater is improved;

thirdly, the demulsified wastewater enters an air flotation area, a bubble generator generates a large amount of micro bubbles to capture floating oil and suspended matters to the water surface, and the floating oil and the suspended matters are scraped to a wastewater oil groove on the side wall of an air flotation oil removal tank by a slag scraper in a standing area;

conveying the treated wastewater into a neutralization area of a coagulation reaction device by a second lifting pump, adding an alkaline agent, and adjusting the pH value to 8-9; then overflowing to a reaction zone, adding a PAC (polyaluminium chloride) medicament, overflowing flocculating constituents with larger impurity stroke particles in the wastewater to the flocculation zone, adding a PAM (polyacrylamide) medicament to accelerate the combination of the flocculating constituents, and adding a scale inhibitor when the concentration of magnesium and aluminum ions is higher to prevent impurities from scaling in a pipeline and influencing the normal operation of equipment;

conveying the wastewater containing the larger flocculating constituent into a clarification concentration device by a third lifting pump for gravity separation, overflowing supernatant liquor into a clear water area through a cofferdam, settling sludge to the bottom of the clarification concentration device, dewatering the sludge by a sludge treatment device, and conveying the filtrate after desliming back to an inlet of the clarification concentration device by a filtrate return pump;

conveying the water in the clear water area to a cyclone separator by a clear water pump to further remove impurities in the clear water, and returning the high-concentration impurity water at the lower water outlet to a clarification and concentration device;

and seventhly, low-impurity clean water at the upper water outlet of the cyclone separator enters a multi-medium filter and a stainless steel security filter for filtering, the filtered water is up to standard reinjection water, enters a clean water buffer tank, and is reinjected through a reinjection pump.

The invention has the beneficial effects that:

the invention aims at the 'oil-in-water' and 'water-in-oil' emulsified oil in the oil extraction wastewater, adopts a method of combining a demulsifier and ultrasonic waves, can better destroy a hydration film thereof, increases the collision chance between oil droplets, ensures that the emulsified oil is rapidly destabilized and demulsified, enlarges the oil droplets, can be more easily absorbed by micro bubbles and floats out of the water surface for removal, then treats the acidity and alkalinity of the oil extraction wastewater, ensures that the oil extraction wastewater is alkaline, and after the system is alkaline, carbonate ions, hydrogen ions, calcium ions, magnesium ions and the like in the oil extraction wastewater react with each other to generate precipitates under the alkaline condition, can promote the passivation of metals, reduce the corrosion of the metals, and can also eliminate a plurality of bacteria, thereby realizing the high-efficiency treatment of the oil extraction wastewater, then treats the small suspended particles by a coagulation method, a coagulant is added into the wastewater, a flocculating agent enables suspended matters of the wastewater to be suspended, continuously aggregate to form a precipitate. The flocculated wastewater enters a clarification concentration device, and supernatant liquor is subjected to impurity removal through a cyclone and then passes through two different filters, so that impurities in the wastewater can be greatly removed, and the wastewater is discharged after reaching the standard.

Drawings

FIG. 1 is a schematic diagram of an oilfield exploitation wastewater treatment device according to the present invention;

FIG. 2 is a demulsification air-flotation oil removal device according to the invention;

FIG. 3 is a diagram of a coagulation reaction apparatus according to the present invention.

In the figure: 1 a waste water tank; 101 a first lift pump; 2 demulsifying air flotation oil removing device; 201 second lift pump; 21 air flotation oil removal tank; 211 a breaking area; 212 an air flotation zone; 213 a standing area; 214 a sump of waste oil; 22 a demulsifier dosing device; 23 an ultrasonic transmitter; 24 a bubble generator; 241 aeration plate; 25, a slag scraper; 26 a filter screen layer; 27 a mixing baffle; 28 a heating device; 29 material guiding inclined plates; 3, a coagulation reaction device; 301 a third lift pump; 31 a neutralization zone; 311 an alkali dosing device; 312 a pH detection device; 32 a reaction zone; 321PAC dosing device; 33 a flocculation zone; 331PAM dosing device; 332 antisludging agent dosing device; 34 a stirring device; 4, a clarification and concentration device; 401 clean water pump; 402 sludge feeding pump; 41 a clear water area; 5 a multi-media filter; 6 stainless steel tube safety filter; 7 a sludge treatment device; 701 returning the filtrate to the pump; 8, a clear water buffer tank; 801 a reinjection pump; 9 a cyclone separator.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-3, an oil field exploitation wastewater treatment device comprises a wastewater tank 1, a demulsification air flotation oil removal device 2, a coagulation reaction device 3, a clarification concentration device 4, a multi-media filter 5, a stainless steel security filter 6 and a sludge treatment device 7;

the wastewater tank 1, the demulsification air-flotation oil removal device 2, the coagulation reaction device 3, the clarification concentration device 4, the multi-medium filter 5 and the stainless steel security filter 6 are sequentially connected through pipelines;

a first lifting pump 101 is arranged on a pipeline between the wastewater tank 1 and the demulsification air-flotation oil removal device 2;

a second lifting pump 201 is arranged on a pipeline between the demulsification air-flotation oil removal device 2 and the coagulation reaction device 3;

a third lifting pump 301 is arranged on a pipeline between the coagulation reaction device 3 and the clarification concentration device 4;

a clear water pump 401 is arranged on a pipeline between the clarification and concentration device 4 and the multi-media filter 5;

the rear part of the stainless steel security filter 6 is connected with a clear water buffer tank 8 through a pipeline, and the clear water buffer tank 8 is provided with a reinjection pump 801 through a pipeline;

the sludge outlet at the bottom of the clarification and concentration device 4 is connected with the sludge treatment device 7 through a pipeline, a sludge feeding pump 402 is arranged between the pipelines, the filtrate outlet of the sludge treatment device 7 is connected with the inlet of the clarification and concentration device 4 through a pipeline, and a filtrate return pump 701 is arranged on the pipeline.

In practical application, the demulsification air-flotation oil removal device 2 comprises an air-flotation oil removal tank 21, a demulsifier dosing device 22, an ultrasonic transmitter 23, a bubble generator 24 and a slag scraper 25;

the air flotation de-oiling tank 21 is divided into a milk breaking area 211, an air flotation area 212 and a standing area 213 by two partition plates, the milk breaking area 211 is communicated with the lower part of the air flotation area 212, the air flotation area 212 is communicated with the upper part of the standing area 213, the top of the milk breaking area 211 is provided with a wastewater inlet and a demulsifier dosing inlet and is provided with an inclined filter screen layer 26, a plurality of layers of '/' alternate mixing baffles 27 are arranged below the filter screen layer 26 and can rapidly stir and mix wastewater and demulsifier, a plurality of heating devices 28 are arranged between the mixing baffles 27, the bottom of the milk breaking area 211 is also provided with an ultrasonic emitter 23, the bottom of the air flotation area 212 is provided with an aeration plate 241, the aeration plate 241 is connected with a bubble generator 24, the top of the standing area 213 is provided with a slag scraper 25, a material guide inclined plate 29 and a waste oil groove 214, and a waste liquid outlet is arranged at the middle position of the side surface of the standing area 213.

In practical application, the coagulation reaction device 3 comprises a neutralization zone 31, a reaction zone 32 and a flocculation zone 33 which are connected in series, two layers of partition plates are arranged between the neutralization zone 31, the reaction zone 32 and the flocculation zone 33, so that waste liquid enters and exits from the bottom, an alkali dosing device 311, a PAC dosing device 321 and a PAM dosing device 331 are respectively arranged on the three zones, stirring devices 34 are respectively arranged on the three zones, a scale inhibitor dosing device 332 is also arranged on the flocculation zone 33, a pH detection device 312 is also arranged in the neutralization zone 31, and a waste water outlet of the coagulation reaction device 3 is arranged at the bottom of the flocculation zone 33.

In practical application, the wastewater inlet pipeline of the clarification and concentration device 4 extends below the liquid level, sludge sinks, supernatant liquid passes through the cofferdam and enters the clear water area 41, and the inlet pipeline of the clear water pump 401 is arranged on the side surface of the clear water area 41.

In practical application, a cyclone separator 9 is further arranged between the clean water pump 401 and the multi-media filter 5, an upper water outlet of the cyclone separator 9 is connected with the multi-media filter 5 through a pipeline, and a lower water outlet of the cyclone separator 9 returns to the clarification and concentration device 4 through a pipeline.

In practical application, the filter element of the stainless steel cartridge filter 6 is PP melt-blown cloth.

In practical application, the sludge treatment device 7 is a filter press.

firstly, conveying the wastewater from the wastewater tank 1 to a demulsification air flotation oil removal device 2 by a first lifting pump 101, and filtering by a filter screen layer 26 to remove large-particle impurities;

secondly, the wastewater is heated by a heater 28 in the emulsion breaking area 211 and is subjected to the combined action of a chemical emulsion breaker and ultrasonic waves, so that the emulsion stabilizing condition is eliminated, and the emulsion breaking efficiency of the wastewater is improved;

thirdly, the demulsified wastewater enters an air flotation zone 212, a large amount of micro bubbles are generated by a bubble generator 24, the floating oil and the suspended matters are captured to the water surface, and the floating oil and the suspended matters are scraped to a wastewater oil groove 214 on the side wall of an air flotation oil removal tank 21 by a residue scraper 25 of a standing zone 213;

fourthly, the treated wastewater is conveyed into a neutralization area 31 of the coagulation reaction device 3 by a second lifting pump 201, and an alkaline medicament is added to adjust the pH value to 8-9; then overflowing to a reaction zone 32, adding a PAC (polyaluminium chloride) medicament, overflowing flocs with larger impurity stroke particles in the wastewater to a flocculation zone 33, adding a PAM (polyacrylamide) medicament to accelerate the combination of the flocs, and adding a scale inhibitor when the concentration of magnesium and aluminum ions is higher to prevent impurities from scaling in a pipeline and influencing the normal operation of equipment;

fifthly, conveying the wastewater containing larger flocculating constituents into a clarification concentration device 4 by a third lifting pump 301 for gravity separation, overflowing supernatant into a clear water area 41 through a cofferdam, settling sludge to the bottom of the clarification concentration device 4, dewatering the sludge by a sludge treatment device 7, and conveying the filtrate after desliming back to an inlet of the clarification concentration device 4 by a filtrate return pump 701;

sixthly, conveying the water in the clear water area into a cyclone separator 9 by a clear water pump 401 to further remove impurities in the clear water, and returning the high-concentration impurity water at the lower water outlet to the clarification and concentration device 4;

and seventhly, low-impurity clean water at the upper water outlet of the cyclone separator 9 enters the multi-medium filter 5 and the stainless steel security filter 6 for filtering, the filtered water is up to standard reinjection water, enters the clean water buffer tank 8, and is reinjected through the reinjection pump 801.

In conclusion, the equipment and the method for treating the oil field exploitation wastewater have the advantages of high efficiency and high-quality treatment.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the foregoing embodiments are merely illustrative of the technical spirit and features of the present invention, and the present invention is not limited thereto but may be implemented by those skilled in the art.

Claims

1. The utility model provides an oil field exploitation waste water treatment equipment which characterized in that: comprises a waste water tank (1), a demulsification air-flotation oil removal device (2), a coagulation reaction device (3), a clarification concentration device (4), a multi-medium filter (5), a stainless steel security filter (6) and a sludge treatment device (7);

the waste water tank (1), the demulsification air-flotation oil removal device (2), the coagulation reaction device (3), the clarification concentration device (4), the multi-medium filter (5) and the stainless steel security filter (6) are sequentially connected through pipelines;

a first lifting pump (101) is arranged in a pipeline between the wastewater tank (1) and the demulsification air flotation oil removal device (2);

a second lifting pump (201) is arranged on a pipeline between the demulsification air flotation oil removal device (2) and the coagulation reaction device (3);

a third lifting pump (301) is arranged on a pipeline between the coagulation reaction device (3) and the clarification concentration device (4);

a clear water pump (401) is arranged on a pipeline between the clarification concentration device (4) and the multi-medium filter (5);

a clear water buffer tank (8) is connected behind the stainless steel security filter (6) through a pipeline, and a reinjection pump (801) is installed on the clear water buffer tank (8) through a pipeline;

the sludge treatment device is characterized in that a sludge outlet at the bottom of the clarification and concentration device (4) is connected with a sludge treatment device (7) through a pipeline, a sludge feeding pump (402) is arranged between the pipelines, a filtrate outlet of the sludge treatment device (7) is connected with an inlet of the clarification and concentration device (4) through a pipeline, and a filtrate return pump (701) is arranged on the pipeline.

2. The oil field exploitation wastewater treatment equipment according to claim 1, wherein: the demulsification air-flotation oil removal device (2) comprises an air-flotation oil removal tank (21), a demulsifier dosing device (22), an ultrasonic transmitter (23), a bubble generator (24) and a slag scraper (25);

the air floatation oil removal tank (21) is divided into a milk breaking area (211), an air floatation area (212) and a standing area (213) by two partition plates, the milk breaking area (211) is communicated with the lower part of the air floatation area (212), the air floatation area (212) is communicated with the upper part of the standing area (213), the top of the milk breaking area (211) is provided with a wastewater inlet and a demulsifier feeding inlet, and is provided with an obliquely arranged filter screen layer (26), a plurality of layers of "/" "alternate mixing baffles (27) are arranged below the filter screen layer (26) and can rapidly stir and mix wastewater and demulsifier, a plurality of heating devices (28) are arranged between the mixing baffles (27), the bottom of the milk breaking area (211) is also provided with an ultrasonic transmitter (23), the bottom of the air floatation area (212) is provided with an aeration plate (241), the aeration plate (241) is connected with a bubble generator (24), and the top of the standing area (213) is provided with a slag scraper (25), A material guide sloping plate (29) and a waste oil groove (214), and a waste liquid outlet is arranged at the middle position of the side surface of the standing area (213).

3. The oil field exploitation wastewater treatment equipment according to claim 1, wherein: coagulation reaction device (3) are including neutralization zone (31), reaction zone (32), flocculation district (33) of establishing ties, all be equipped with two-layer baffle between neutralization zone (31), reaction zone (32), flocculation district (33), make the waste liquid all go into down and go out, install alkali charge device (311), PAC charge device (321), PAM charge device (331) and be equipped with agitating unit (34) respectively on the three subregion, scale inhibitor charge device (332) are still installed in flocculation district (33), neutralization zone (31) still is equipped with pH detection device (312), the bottom in flocculation district (33) is located in the waste water export of coagulation reaction device (3).

4. The oil field exploitation wastewater treatment equipment according to claim 1, wherein: a wastewater inlet pipeline of the clarification and concentration device (4) extends below the liquid level, sludge sinks, supernatant liquid passes through the cofferdam and enters the clear water area (41), and an inlet pipeline of the clear water pump (401) is arranged on the side surface of the clear water area (41).

5. The oil field exploitation wastewater treatment equipment according to claim 1, wherein: and a cyclone separator (9) is also arranged between the clean water pump (401) and the multi-media filter (5), the upper water outlet of the cyclone separator (9) is connected with the multi-media filter (5) through a pipeline, and the lower water outlet returns to the clarification and concentration device (4) through a pipeline.

6. The oil field exploitation wastewater treatment equipment according to claim 1, wherein: the filter element of the stainless steel cartridge filter (6) is PP melt-blown cloth.

7. The oil field exploitation wastewater treatment equipment according to claim 1, wherein: the sludge treatment device (7) is a filter press.

8. A method for treating oil field exploitation wastewater is characterized by comprising the following steps: the method comprises the following steps:

firstly, conveying the wastewater from a wastewater tank (1) to a demulsification air flotation oil removal device (2) by a first lifting pump (101), and filtering by a filter screen layer (26) to remove large-particle impurities;

secondly, the wastewater is heated by a heater (28) in a demulsification area (211) and is subjected to the combined action of a chemical demulsifying agent and ultrasonic waves, so that the emulsion stabilization condition is eliminated, and the demulsification efficiency of the wastewater is improved;

thirdly, the wastewater after demulsification enters an air flotation area (212), a bubble generator (24) generates a large amount of micro bubbles, floating oil and suspended matters are captured to the water surface, and the floating oil and the suspended matters are scraped to a wastewater tank (214) on the side wall of the air floatation oil removal tank (21) by a slag scraper (25) of a standing area (213);

fourthly, the treated wastewater is conveyed into a neutralization area (31) of the coagulation reaction device (3) by a second lifting pump (201), an alkaline medicament is added, and the pH value is adjusted to 8-9; then overflowing to a reaction zone (32), adding a PAC (polyaluminium chloride) medicament, overflowing flocculating constituents with larger impurity stroke particles in the wastewater to a flocculation zone (33), adding a PAM medicament to accelerate the combination of the flocculating constituents, and adding a scale inhibitor when the concentration of magnesium and aluminum ions is higher to prevent impurities from scaling in a pipeline and influencing the normal operation of equipment;

fifthly, conveying the wastewater containing larger flocculating constituents into a clarification concentration device (4) by a third lifting pump (301) for gravity separation, overflowing supernatant liquor into a clear water area (41) through a cofferdam, sinking sludge to the bottom of the clarification concentration device (4), dewatering the sludge by a sludge treatment device (7), and conveying the filtrate after desliming back to an inlet of the clarification concentration device (4) by a filtrate return pump (701);

sixthly, conveying the water in the clear water area into a cyclone separator (9) by a clear water pump (401) to further remove impurities in the clear water, and returning the high-concentration impurity water at the lower water outlet to a clarification and concentration device (4);

and seventhly, low-impurity clean water at the upper water outlet of the cyclone separator (9) enters the multi-medium filter (5) and the stainless steel security filter (6) for filtering, the filtered water is up-to-standard reinjection water, enters the clean water buffer tank (8), and is reinjected through the reinjection pump (801).