A multi-phase extraction separation system for a contaminated site

Abstract

The application provides a contaminated site multi-phase extraction separation system, which comprises a solid phase separation device, a gas phase separation device, an NAPL phase separation device, a vacuum air extraction device and a VOC treatment device, and can separate silt containing adsorbed organic matter, gas containing volatile organic matter, water containing dissolved organic matter, light non-aqueous phase liquid (LNAPL) and heavy non-aqueous phase liquid (DNAPL). The application integrates multi-phase extraction and multi-phase separation, can realize extraction and separation simultaneously, and can significantly improve the remediation efficiency of soil organic pollution and the treatment efficiency of pollutants, and is beneficial to popularization and application of the system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of contaminated site soil remediation, and particularly relates to a contaminated site multi-phase extraction separation system. BACKGROUND

[0002] The acceleration of urbanization process and the rapid development of chemical industry have produced a large amount of organic waste, resulting in an increasing number of contaminated sites year by year, so efficient contaminated site remediation technology is urgently needed. Soil organic pollutants are mainly divided into volatile organic compounds (VOC), dissolved organic matter (DOM), adsorbed organic matter and non-aqueous phase liquids (NAPL), among which NAPL can be divided into light non-aqueous phase liquids (LNAPL) and dense non-aqueous phase liquids (DNAPL) according to density. At present, the remediation technologies for contaminated sites mainly include multi-phase extraction, chemical oxidation, solidification and stabilization, biodegradation, etc., among which the multi-phase extraction technology can extract underground contaminated water, gas and NAPL to the ground by vacuum method to reduce the content of organic pollutants in soil and groundwater. Due to its rapid control and simultaneous remediation effect on underground pollution, the multi-phase extraction technology is widely used. At present, the multi-phase extraction equipment in China is in the initial development stage, and the existing multi-phase extraction equipment can only extract underground pollutants and transport them to hazardous waste treatment institutions, which is difficult to realize on-site separation and treatment. SUMMARY

[0003] In view of the deficiencies of the existing multi-phase extraction equipment, the present application provides a contaminated site multi-phase extraction separation system.

[0004] The technical scheme of the present application is as follows:

[0005] A contaminated site multi-phase extraction separation system, comprising: a solid phase separation device a, a gas phase separation device b, a NAPL phase separation device c, a vacuum air extraction equipment d, and a VOC treatment device e, wherein:

[0006] The solid phase separation device a is used for separating the silt containing adsorbed organic matter in the extract, and the extract after separating the silt is transported to the gas phase separation device b;

[0007] The gas phase separation device b is used for separating the gas containing volatile organic compounds in the extract, and the water containing dissolved organic matter and the non-aqueous phase liquid NAPL are pumped into the NAPL phase separation device c;

[0008] The NAPL phase separation device c is used for separating water containing dissolved organic matter, light non-aqueous phase liquid LNAPL and heavy non-aqueous phase liquid DNAPL;

[0009] The vacuum air extraction device d provides negative pressure for multiphase extraction construction, extracts the gas containing volatile organic matter in the tank of the gas phase separation device b, and discharges the purified gas after the VOC treatment device e.

[0010] By adopting the above scheme, the present application has the following beneficial effects:

[0011] 1. The contaminated site multiphase extraction separation system of the present application integrates multiphase extraction and multiphase separation, and can simultaneously realize extraction and separation, thereby significantly improving the remediation efficiency of soil organic pollution and the treatment efficiency of pollutants.

[0012] 2. For the separation of the extraction, the solid phase separation device, the gas phase separation device and the NAPL phase separation device are developed to separate the silt containing adsorbed organic matter, the gas containing volatile organic matter, the water containing dissolved organic matter, the LNAPL and the DNAPL, so as to facilitate further treatment. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the system of the present application.

[0014] Figure 2 It is a schematic diagram of the structure of the system of the present application.

[0015] Figure 3 It is a schematic diagram of the appearance structure of the solid phase separation device.

[0016] Figure 4 It is a schematic diagram of the appearance structure of the solid phase separation device.

[0017] Figure 5 It is a schematic diagram of the internal structure of the solid phase separation device.

[0018] Figure 6 It is a schematic diagram of the structure of the gas phase separation device.

[0019] Figure 7 It is a schematic diagram of the internal structure of the NAPL phase separation device.

[0020] Figure 8 It is a schematic diagram of the assembly of the rotating structure in the NAPL phase separation device.

[0021] Figure 9 It is a sectional view of the rotating structure in the NAPL phase separation device.

[0022] Figure 10 It is Figure 9Fig. 1 is a schematic diagram of the cross-sectional structure of A-A', B-B', C-C', D-D', E-E', and F-F'.

[0023] Figure 11 Fig. 2 is a schematic diagram of the process flow of the system.

[0024] Reference signs:

[0025] Solid phase separation device a, wherein: extract inlet a-1, solid phase separation device housing a-2, first filter screen a-3-1, second filter screen a-3-2, third filter screen a-3-3, fourth filter screen a-3-4, flow meter a-4, first solid phase separation electric control valve a-5-1, second solid phase separation electric control valve a-5-2, third solid phase separation electric control valve a-5-3, fourth solid phase separation electric control valve a-5-4, solid phase separation liquid level meter a-6, water spray pipe a-7, helical blade a-8, solid phase separation motor a-9, solid phase separation belt a-10, solid phase separation outlet a-11;

[0026] Gas phase separation device b, wherein: gas phase separation inlet b-1, gas phase separation tank b-2, gas phase separation electric control valve b-3, gas pressure sensor b-4, gas phase separation liquid level meter b-5, gas outlet b-6, centrifugal pump b-7, check valve b-8, liquid outlet b-9;

[0027] NAPL phase separation device c, wherein: mixed liquid inlet c-1, device housing c-2, NAPL phase separation motor c-3, NAPL phase separation belt c-4, rotating structure c-5, separation pipe c-6, first NAPL phase separation electric control valve c-7-1, second NAPL phase separation electric control valve c-7-2, third NAPL phase separation electric control valve c-7-3, water outlet c-8, LNAPL outlet c-9, DNAPL outlet c-10, first electrode group c-11-1, second electrode group c-11-2, third electrode group c-11-3, first power supply slip ring c-12-1, second power supply slip ring c-12-2, third power supply slip ring c-12-3, rotating shaft center c-13, wherein the rotating structure c-5 comprises: bearing c-5-1, rotating housing c-5-2, rotating blade c-5-3, first bottom plate c-5-4, first center circular hole c-5-4-1, arc-shaped opening c-5-4-2, first circular opening c-5-4-3, second bottom plate c-5-5, second center circular hole c-5-5-1, groove c-5-5-2, second circular opening c-5-5-3, third bottom plate c-5-6, third center circular hole c-5-6-1, rectangular groove c-5-6-2, centrifugal zone inlet c-5-7, first flow channel c-5-8, second flow channel c-5-9, third flow channel c-5-10, first connecting pipe c-5-11, second connecting pipe c-5-12, third connecting pipe c-5-13.

[0028] a vacuum air extraction device d, wherein: a gas inlet d-1;

[0029] a VOC treatment device e. DETAILED DESCRIPTION

[0030] The technical solutions provided in the present application will be further described below in combination with specific embodiments and their accompanying drawings. The advantages and features of the present application will be more apparent in combination with the following description.

[0031] As shown in Figure 1 , Figure 2 a contaminated site multi-phase extraction separation system, comprising: a solid phase separation device a, a gas phase separation device b, a NAPL phase separation device c, a vacuum air extraction device d, a VOC treatment device e, wherein:

[0032] The solid phase separation device a is used to separate the silt containing adsorbed organic matter in the extract, and the separated silt is transported to the gas phase separation device b;

[0033] The gas phase separation device b is used to separate the gas containing volatile organic compounds in the extract, and the water containing dissolved organic matter and the non-aqueous phase liquid (NAPL) are pumped into the NAPL phase separation device c;

[0034] The NAPL phase separation device c is used to separate the water containing dissolved organic matter, light non-aqueous phase liquid (LNAPL) and heavy non-aqueous phase liquid (DNAPL);

[0035] The vacuum air extraction device d provides negative pressure for the multi-phase extraction construction, and the gas containing volatile organic compounds in the tank of the gas phase separation device b is extracted and discharged after purification by the VOC treatment device e.

[0036] The solid phase separation device a is used to separate the silt containing adsorbed organic matter in the extract, and the separated silt is transported to the gas phase separation device b, comprising: an extract inlet a-1, a solid phase separation device shell a-2, a filter screen, a flow meter a-4, an electric control valve, a solid phase separation liquid level meter a-6, a water spray pipe a-7, a spiral blade a-8, a solid phase separation motor a-9, a solid phase separation belt a-10, and a solid phase separation outlet a-11, as shown in Figure 3 , Figure 4 , Figure 5 wherein:

[0037] The electric control valve has four, which are respectively a first solid phase separation electric control valve a-5-1, a second solid phase separation electric control valve a-5-2, a third solid phase separation electric control valve a-5-3, and a fourth solid phase separation electric control valve a-5-4; the first solid phase separation electric control valve a-5-1 is arranged at the top of the solid phase separation device shell a-2, and is used to adjust the internal air pressure of the solid phase separation device;

[0038] The extract inlet a-1 is located on one side of the outer shell a-2 of the solid phase separation equipment and is connected to the extraction well (not shown in the figure);

[0039] The solid phase separation outlet a-11 is located on the other side of the solid phase separation equipment shell a-2. A flow meter a-4 and a second solid phase separation electrically controlled valve a-5-2 are provided at the front end of the solid phase separation outlet a-11 of the gas phase separation device b.

[0040] There are four filters, arranged in descending order of pore size as filter a-3-1, filter a-3-2, filter a-3-3, and filter a-3-4, which are used for multi-stage filtration of silt containing adsorbed organic matter. They are arranged evenly in sequence inside the outer shell a-2 of the solid phase separation equipment, with filter a-3-1 being close to the extract inlet a-1.

[0041] There are four water spray pipes a-7, which are arranged behind each filter screen. The four water spray pipes a-7 are connected to an external water source through the third solid phase separation electrically controlled valve a-5-3, which is used to spray water onto the filter screen to clean it.

[0042] The spiral blade a-8 is located at the bottom of the outer shell a-2 of the solid phase separation equipment. One end of the spiral blade a-8 is equipped with a fourth solid phase separation electrically controlled valve a-5-4 for discharging silt and sand. The other end of the spiral blade a-8 is connected to the output shaft of the solid phase separation motor a-9 through the solid phase separation belt a-10. The solid phase separation motor a-9 provides rotational power to the spiral blade a-8 through the solid phase separation belt a-10. The rotation of the spiral blade a-8 discharges the silt and sand containing adsorbed organic matter that has been washed down through the fourth solid phase separation electrically controlled valve a-5-4.

[0043] The level gauge a-6 is used to monitor the liquid level inside the solid phase separation device and is arranged on the side of the solid phase separation device housing a-2.

[0044] The gas phase separation device b is used to separate gases containing volatile organic compounds from the extract, and includes: a gas phase separation inlet b-1, a tank b-2, a gas phase separation electrically controlled valve b-3, a gas pressure sensor b-4, a gas phase separation level gauge b-5, a gas outlet b-6, a centrifugal pump b-7, a check valve b-8, and a liquid outlet b-9, as shown. Figure 6 As shown, where:

[0045] The gas phase separation inlet b-1 and the gas outlet b-6 are located at the upper end of the tank b-2. The gas phase separation inlet b-1 is connected to the solid phase separation outlet a-11 of the solid phase separation device a, the gas outlet b-6 is connected to the gas inlet of the vacuum pumping device d, and the liquid outlet b-9 is connected to the mixed liquid inlet c-1 of the c-NAPL phase separation device.

[0046] A gas phase separation electrically controlled valve b-3 is arranged on the upper side of the tank b-2, for adjusting the gas pressure in the tank;

[0047] A gas pressure sensor b-4 is arranged on the upper side of the tank b-2, for monitoring the gas pressure in the tank;

[0048] A gas phase separation liquid level meter b-5 is arranged on the side of the tank b-2, for monitoring the liquid level in the tank;

[0049] The bottom of the tank b-2 is connected to the inlet of a centrifugal pump b-7 through a pipe, the outlet of the centrifugal pump b-7 is connected to a liquid outlet b-9, a check valve b-8 is arranged between the outlet of the centrifugal pump b-7 and the liquid outlet b-9, the liquid passes through the check valve b-8 and is discharged through the liquid outlet b-9, the liquid outlet b-9 is connected to the mixed liquid inlet c-1 of the NAPL phase separation device c, the centrifugal pump b-7 is used to provide power during the liquid discharge process, and the check valve b-8 is used to prevent the liquid from flowing back.

[0050] The NAPL phase separation device c is used to separate water containing dissolved organic matter, light non-aqueous phase liquid (LNAPL) and heavy non-aqueous phase liquid (DNAPL), and comprises a mixed liquid inlet c-1, a device shell c-2, a NAPL phase separation motor c-3, a NAPL phase separation belt c-4, a rotating structure c-5, a separation pipe c-6, a first NAPL phase separation electrically controlled valve c-7-1, a second NAPL phase separation electrically controlled valve c-7-2, a third NAPL phase separation electrically controlled valve c-7-3, a water outlet c-8, a LNAPL outlet c-9, a DNAPL outlet c-10, a first electrode group c-11-1, a second electrode group c-11-2, a third electrode group c-11-3, a first power supply slip ring c-12-1, a second power supply slip ring c-12-2, and a third power supply slip ring c-12-3, as shown in Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 Wherein:

[0051] The mixed liquid inlet c-1 is arranged at the upper end of the rotating structure c-5, and the mixed liquid inlet c-1 is connected to the liquid outlet b-9 of the gas phase separation device b;

[0052] The rotating structure c-5 is installed in the equipment shell c-2, the upper part of the rotating structure c-5 is communicated with the mixed liquid inlet c-1, and the lower part is connected with the separation pipe c-6; the rotating structure c-5 is used for high-speed rotation to realize mutual separation of water containing dissolved organic matter, light non-aqueous phase liquid (LNAPL) and heavy non-aqueous phase liquid (DNAPL), including bearing c-5-1, rotating shell c-5-2, rotating blade c-5-3, first bottom plate c-5-4, second bottom plate c-5-5, third bottom plate c-5-6, first connecting pipe c-5-11, second connecting pipe c-5-12 and third connecting pipe c-5-13; the rotating shell c-5-2 and the first bottom plate c-5-4 are provided with grooves, the lower part of the rotating blade c-5-3 is clamped into the groove of the first bottom plate c-5-4, the upper part of the rotating blade c-5-3 is clamped into the groove of the rotating shell c-5-2, the rotating shell c-5-2, the rotating blade c-5-3, the first bottom plate c-5-4, the second bottom plate c-5-5 and the third bottom plate c-5-6 are fixed as a whole by bolts, and a centrifugal zone inlet and three independent flow channels are formed in the rotating structure, the upper and lower parts of the whole are respectively provided with two bearings c-5-1, so as to form the rotating structure c-5.

[0053] Further, the rotating structure c-5:

[0054] The rotating shell c-5-2 is a circular truncated cone structure, which is narrow at the top and wide at the bottom;

[0055] The rotating blade c-5-3 is provided with a centrifugal zone inlet c-5-7 between the top edge of the rotating blade c-5-3 and the rotating shell c-5-2;

[0056] The rotating blade c-5-3 is a grid structure, and is provided with a first flow channel c-5-8 and a second flow channel c-5-9 in the interior, and is provided with a third flow channel c-5-10 between the rotating blade c-5-3 and the side wall of the rotating shell c-5-2, and the three flow channels are communicated in the horizontal direction through the grid of the rotating blade c-5-3;

[0057] The first bottom plate c-5-4 is provided with a first circular hole c-5-4-1 in the center, which is communicated with the first flow channel c-5-8 in the interior of the rotating blade c-5-3; is provided with an arc-shaped opening c-5-4-2 in the middle, which is communicated with the second flow channel c-5-9 in the interior of the rotating blade c-5-3; and is provided with a first circular opening c-5-4-3 at the edge, which is communicated with the third flow channel c-5-10 in the interior of the rotating blade c-5-3:

[0058] The second bottom plate c-5-5 is provided with a second circular hole c-5-5-1 in the center, and a groove c-5-5-2 is arranged around the second circular hole c-5-5-1, the groove c-5-5-2 is opposite to and communicates with the arc-shaped opening c-5-4-2 of the first bottom plate c-5-4, and further communicates with the second flow channel c-5-9 in the rotating vane c-5-3; the edge is provided with a second circular opening c-5-5-3, which communicates with the first circular opening c-5-4-3 at the edge of the first bottom plate c-5-4, and further communicates with the third flow channel c-5-10 in the rotating vane c-5-3;

[0059] The third bottom plate c-5-6 is provided with a third circular hole c-5-6-1 in the center, and a rectangular groove c-5-6-2 is arranged radially outward at the edge of the third circular hole c-5-6-1, the rectangular groove c-5-6-2 communicates with the circular opening c-5-5-3 at the edge of the second bottom plate c-5-5, and further communicates with the third flow channel c-5-10 in the rotating vane c-5-3;

[0060] The hole diameters of the first connecting pipe c-5-11, the second connecting pipe c-5-12 and the third connecting pipe c-5-13 are arranged from small to large, wherein the first connecting pipe c-5-11 is connected to the bottom of the first bottom plate c-5-4 and communicates with the first central circular hole c-5-4-1, the second connecting pipe c-5-12 is connected to the bottom of the second bottom plate c-5-5 and communicates with the second central circular hole c-5-5-1, and the third connecting pipe c-5-13 is connected to the bottom of the third bottom plate c-5-6 and communicates with the third central circular hole c-5-6-1;

[0061] The above three connecting pipes are nested in sequence and have gaps between adjacent inner and outer walls, sealing measures are arranged at the connection positions of the three connecting pipes and the bottom plates, and finally

[0062] The first connecting pipe c-5-11 communicates with the first circular hole c-5-4-1 in the center of the first bottom plate c-5-4 and the first flow channel c-5-8 in the rotating vane c-5-3 in sequence, forming a complete flow channel, i.e. LNAPL flow channel, for discharging LNAPL;

[0063] The gap between the inner wall of the second connecting pipe c-5-12 and the outer wall of the first connecting pipe c-5-11 forms a flow channel, and communicates with the second circular hole c-5-5-1 in the center of the second bottom plate c-5-5, the groove c-5-5-2, the arc-shaped opening c-5-4-2 in the middle of the first bottom plate c-5-4 and the second flow channel c-5-9 in the rotating vane c-5-3 in sequence, forming a complete flow channel, i.e. water flow channel, for discharging water containing dissolved organic matter;

[0064] The gap between the inner wall of the third connecting pipe c-5-13 and the outer wall of the second connecting pipe c-5-12 forms a flow channel, and is communicated with the third circular hole c-5-6-1 in the center of the third bottom plate c-5-6, the rectangular groove c-5-6-2, the second circular opening c-5-5-3 in the edge of the second bottom plate c-5-5, the first circular opening c-5-4-3 in the edge of the first bottom plate c-5-4, and the third flow channel c-5-10 in the interior of the rotating vane c-5-3 in turn, forming a complete flow channel, i.e. a DNAPL flow channel, for discharging DNAPL.

[0065] The separation pipe c-6 comprises three channel outlets, which are communicated with the three complete flow channels (LNAPL flow channel, water flow channel, DNAPL flow channel) of the rotating structure c-5 respectively, and the separation pipe c-6 outputs in three ways: LNAPL is discharged downward through the separation pipe c-6 and is discharged from the LNAPL outlet c-9 through the second NAPL phase separation electric valve c-7-2; water containing dissolved organic matter is discharged to the right through the separation pipe c-6 and is discharged from the water outlet c-8 through the first NAPL phase separation electric valve c-7-1; DNAPL is discharged to the left through the separation pipe c-6 and is discharged from the DNAPL outlet c-10 through the third NAPL phase separation electric valve c-7-3;

[0066] The first electrode group c-11-1, the second electrode group c-11-2 and the third electrode group c-11-3 are arranged on the first bottom plate c-5-4, the second bottom plate c-5-5 and the third bottom plate c-5-6 respectively, for measuring the electrical resistivity of the liquid to monitor the separation purity (the electrical resistivity of LNAPL and DNAPL is high, and the electrical resistivity of water containing dissolved organic matter is low), and the three electrode groups are powered through three power supply slip rings, i.e. the first power supply slip ring c-12-1, the second power supply slip ring c-12-2 and the third power supply slip ring c-12-3; as an example, the first power supply slip ring c-12-1 is arranged between the outer wall of the first connecting pipe c-5-11 and the inner wall of the separation pipe c-6, the second power supply slip ring c-12-2 is arranged between the outer wall of the second connecting pipe c-5-12 and the inner wall of the separation pipe c-6, and the third power supply slip ring c-12-3 is arranged between the outer wall of the first connecting pipe c-5-13 and the separation pipe c-6;

[0067] The NAPL phase separation motor c-3 is arranged in the equipment shell c-2, and the output shaft thereof is connected with the rotating structure c-5 through the NAPL phase separation belt c-4, and the NAPL phase separation motor c-3 provides power for the rotating structure c-5 through the NAPL phase separation belt c-4.

[0068] The shunt principle of water and NAPL phase separation is as follows:

[0069] Water and NAPL enter the rotating structure c-5 through the mixed liquid inlet c-1. The mixed liquid then enters the centrifugal zone below the rotating blade c-5-3 through the centrifugal zone inlet c-5-7 at the top edge of the rotating blade c-5-3. The NAPL phase separation motor c-3 provides power to rotate the rotating structure c-5 at high speed. The mixed liquid inside the centrifugal zone is driven to rotate at high speed by the rotating blade c-5-3. Since LNAPL has a lower density than water, LNAPL in the mixed liquid will transfer towards the center of the rotating shaft c-13, that is, LNAPL will transfer to the first flow channel c-5-8 through the grid of the rotating blade c-5-3. Similarly, due to DNAP... L has a density greater than water, so DNAPL in the mixed liquid will move away from the center of the rotation axis c-13. That is, LNAPL will be transferred to the third flow channel c-5-10 through the grid of the rotating blade c-5-3. Water is located between LNAPL and DNAPL. Thus, LNAPL, DNAPL and water are separated. From the center of the rotation axis c-13 outwards, the order is LNAPL, water and DNAPL. The inclined sidewall of the rotating shell c-5-2 helps DNAPL to converge at the outer edge of the bottom of the centrifugation zone. The rotating blade c-5-3 has a conical structure at the center with the cone apex facing downwards, which helps LNAPL to converge at the center of the rotation axis at the bottom of the centrifugation zone.

[0070] Compared to water, LNAPL and DNAPL have higher resistivity. The resistivity of LNAPL at this location is monitored by the first electrode group c-11-1. When the resistivity reaches the set threshold for separating LNAPL, the second NAPL phase separation electrically controlled valve c-7-2 opens, and LNAPL flows through the LNAPL channel and is discharged from LNAPL outlet c-9. Similarly, the resistivity of DNAPL is monitored by the third electrode group c-11-3. When the resistivity reaches the set threshold for separating DNAPL, the third NAPL phase separation electrically controlled valve c-7-3 opens, and DNAPL flows through the DNAPL channel and is discharged from DNAPL outlet c-10. The resistivity of water is monitored by the second electrode group c-11-2. When the resistivity reaches the set threshold for separating water, the first NAPL phase separation electrically controlled valve c-7-1 opens, and water containing dissolved organic matter flows through the water channel and is discharged from water outlet c-8.

[0071] The vacuum pumping device d provides negative pressure for multiphase extraction construction. It includes a gas inlet d-1 and a gas outlet. The gas inlet d-1 is connected to the gas outlet b-6 of the gas phase separator b, and the gas outlet is connected to the VOC treatment device e. The vacuum pumping device d extracts the gas containing volatile organic compounds from the tank b-2 of the gas phase separator b, which is then purified by the VOC treatment device e before being discharged.

[0072] Based on the above system, multiphase extraction and separation of contaminated sites can be achieved. The system process flow is as follows: Figure 11 As shown.

[0073] Specifically, the implementation process includes the following steps:

[0074] Step 1: Install the system and set the parameters.

[0075] When in use, the extract inlet a-1 of the solid phase separation device a is connected with the extraction well, and multiple extraction wells can be connected at the same time; the third solid phase separation electric control valve a-5-3 is connected with an external water source.

[0076] Before starting the multi-phase extraction separation operation, the states of the electric control valves are set as follows: the first solid phase separation electric control valve a-5-1, the third solid phase separation electric control valve a-5-3, and the fourth solid phase separation electric control valve a-5-4 of the solid phase separation device a are closed, and the second solid phase separation electric control valve a-5-2 is opened; the gas phase separation electric control valve b-3 of the gas phase separation device b is closed; the first NAPL phase separation electric control valve c-7-1, the second NAPL phase separation electric control valve c-7-2, and the third NAPL phase separation electric control valve c-7-3 of the NAPL phase separation device c are closed.

[0077] The parameters include the extraction negative pressure range (the lower limit of the air pressure range and the upper limit of the air pressure range), the flow rate threshold value, the solid phase separation liquid level threshold value, the cleaning time length, the gas phase separation liquid level range (the lower limit of the gas phase separation liquid level range and the upper limit of the gas phase separation liquid level range), the electric resistivity threshold value for separating LNAPL, the electric resistivity threshold value for separating DNAPL, the electric resistivity threshold value for separating water, and the like.

[0078] Step 2: Start extraction.

[0079] 2.1: The vacuum pumping device d operates and cooperates with the gas phase separation electric control valve b-3 to extract the air in the tank body b-2 of the gas phase separation device b to reach the set extraction negative pressure range. Under the action of the vacuum pressure, the extract containing the water, air, sand, and NAPL containing pollutants in the extraction well is sucked into the extract inlet a-1 of the solid phase separation device a.

[0080] 2.2: After the extract passes through the filter screens (in order of the first filter screen a-3-1, the second filter screen a-3-2, the third filter screen a-3-3, and the fourth filter screen a-3-4) in the solid phase separation device a in the order of decreasing pore size, the sand containing adsorbed organic matter is retained on the filter screens, and the water, air, and NAPL enter the gas phase separation device b.

[0081] After the device operates for a certain period of time, the filter screens are blocked by the sand, and the water, air, and NAPL are difficult to pass through, and the extraction flow rate decreases. When the extraction flow rate monitored by the flow meter a-4 is lower than the set flow rate threshold value, the sand on the filter screens is cleaned. The cleaning process is as follows:

[0082] The first solid phase separation electric control valve a-5-1 is opened, the solid phase separation device a inside returns to normal pressure state, at this time, water, air and NAPL continue to slowly enter the gas phase separation device b, the liquid level is monitored through the solid phase separation liquid level meter a-6, when the liquid level is lower than the set solid phase separation liquid level threshold, the second solid phase separation electric control valve a-5-2 is closed, the third solid phase separation electric control valve a-5-3 and the fourth solid phase separation electric control valve a-5-4 are opened, the external water source sprays water to the filter screen through the water spraying pipe a-7, the silt is flushed, the solid phase separation motor a-9 is operated, the silt containing adsorbed organic matter is discharged through the opening of the fourth solid phase separation electric control valve a-5-4 through the spiral blade a-8, when the flushing time reaches the set flushing time length, the third solid phase separation electric control valve a-5-3 and the fourth solid phase separation electric control valve a-5-4 are closed, the solid phase separation motor a-9 stops operating, and the cleaning process is ended; after the cleaning process is ended, if the extraction operation needs to be continued, the states of the electric control valves and the solid phase separation motor a-9 are set to the states at the beginning of the extraction operation, and the extraction operation is continuously performed.

[0083] 2.3: After the water containing pollutants, air and NAPL enter the gas phase separation device b through the gas phase separation inlet b-1, the water and NAPL are located at the lower part of the tank body b-2, the air at the upper part is discharged through the gas outlet b-6 and is discharged into the VOC treatment device e by the vacuum air extraction equipment d, and is discharged after being purified;

[0084] When the gas phase separation liquid level meter b-5 monitors that the liquid level in the tank body b-2 reaches the upper limit of the set gas phase separation liquid level range, the centrifugal pump b-7 and the NAPL phase separation device c start to operate, and LNAPL, DNAPL and water are separated according to the foregoing water, NAPL phase separation shunting principle; when the gas phase separation liquid level meter b-5 monitors that the liquid level in the tank body b-2 is lower than the lower limit of the set gas phase separation liquid level range or the extraction operation needs to be stopped, the centrifugal pump b-7 stops, the NAPL phase separation device c stops, and the NAPL phase separation process is ended.

[0085] Step 3: End of extraction.

[0086] After the extraction operation is ended, the vacuum air extraction equipment d is closed, and the gas phase separation electric control valve b-3 is opened, so that the tank body b-2 inside returns to normal pressure state, and the system stops operating.

[0087] The above description is only a description of the preferred embodiment of the present application, and is not any limitation on the scope of the present application. Any modification or modification made by any person skilled in the art according to the technical content disclosed above should be regarded as an equivalent effective embodiment, and belongs to the protection scope of the technical scheme of the present application.

Claims

1. A multi-phase extraction separation system for a contaminated site, characterized by, Comprise: Solid phase separation device (a), gas phase separation device (b), NAPL phase separation device (c), vacuum air extraction equipment (d), VOC treatment device (e), wherein: The solid phase separation device (a) is used for separating the silt containing adsorbed organic matter in the extract, and the extract after separating the silt is transported to the gas phase separation device (b); The gas phase separation device (b) is used for separating the gas containing volatile organic matter in the extract, and the water containing dissolved organic matter and the non-aqueous phase liquid NAPL are pumped into the NAPL phase separation device (c); The NAPL phase separation device (c) is used for separating the water containing dissolved organic matter and the non-aqueous phase liquid NAPL into water, light non-aqueous phase liquid LNAPL and heavy non-aqueous phase liquid DNAPL; the NAPL phase separation device (c) comprises a mixed liquid inlet (c-1), an equipment shell (c-2), a NAPL phase separation motor (c-3), a NAPL phase separation belt (c-4), a rotating structure (c-5), a separation pipe (c-6), a first NAPL phase separation electric control valve (c-7-1), a second NAPL phase separation electric control valve (c-7-2), a third NAPL phase separation electric control valve (c-7-3), a water outlet (c-8), an LNAPL outlet (c-9), a DNAPL outlet (c-10), a first electrode group (c-11-1), a second electrode group (c-11-2), a third electrode group (c-11-3), a first power supply slip ring (c-12-1), a second power supply slip ring (c-12-2), and a third power supply slip ring (c-12-3), wherein: The mixed liquid inlet (c-1) is arranged on the upper end of the rotating structure (c-5), and the mixed liquid inlet (c-1) is in communication with the liquid outlet in the gas phase separation device (b); The rotating structure (c-5) is installed in the equipment shell (c-2), the upper part of the rotating structure (c-5) is in communication with the mixed liquid inlet (c-1), and the lower part is connected with the separation pipe (c-6); the rotating structure (c-5) comprises a bearing (c-5-1), a rotating shell (c-5-2), a rotating blade (c-5-3), a first bottom plate (c-5-4), a second bottom plate (c-5-5), a third bottom plate (c-5-6), a first connecting pipe (c-5-11), a second connecting pipe (c-5-12), and a third connecting pipe (c-5-13); the rotating shell (c-5-2) and the first bottom plate (c-5-4) are provided with grooves, the lower part of the rotating blade (c-5-3) is clamped into the groove of the first bottom plate (c-5-4), the upper part of the rotating blade (c-5-3) is clamped into the groove of the rotating shell (c-5-2), the rotating shell (c-5-2), the rotating blade (c-5-3), the first bottom plate (c-5-4), the second bottom plate (c-5-5) and the third bottom plate (c-5-6) are fixed as a whole by bolts, and a centrifugal zone inlet and three independent flow channels are formed in the rotating structure, and two bearings (c-5-1) are installed above and below the whole, so as to form the rotating structure; The separation tube (c-6) outputs in three ways: LNAPL is discharged downward through the separation tube (c-6) and is discharged from the LNAPL outlet (c-9) through the second NAPL phase separation electric valve (c-7-2); water containing dissolved organic matter is discharged to the right through the separation tube (c-6) and is discharged from the water outlet (c-8) through the first NAPL phase separation electric valve (c-7-1); and DNAPL is discharged to the left through the separation tube (c-6) and is discharged from the DNAPL outlet (c-10) through the third NAPL phase separation electric valve (c-7-3); The first electrode group (c-11-1), the second electrode group (c-11-2), and the third electrode group (c-11-3) are arranged on the first bottom plate (c-5-4), the second bottom plate (c-5-5), and the third bottom plate (c-5-6), respectively, and the three groups of electrodes are powered through the three groups of power supply slip rings, i.e., the first power supply slip ring (c-12-1), the second power supply slip ring (c-12-2), and the third power supply slip ring (c-12-3); the NAPL phase separation motor (c-3) is arranged in the equipment shell (c-2), and the output shaft of the NAPL phase separation motor (c-3) is connected to the rotating structure (c-5) through the NAPL phase separation belt (c-4), and the NAPL phase separation motor (c-3) provides power for the rotating structure (c-5) through the NAPL phase separation belt (c-4); The vacuum air extraction equipment (d) provides negative pressure for multiphase extraction construction, extracts the gas containing volatile organic compounds in the tank of the gas phase separation device (b), and discharges the extracted gas after purification by the VOC treatment device (e).

2. The multiphase extraction and separation system for contaminated sites according to claim 1, characterized in that, The solid phase separation device (a) comprises: an extraction inlet (a-1), a solid phase separation equipment shell (a-2), a filter screen, a flow meter (a-4), an electric valve, a solid phase separation liquid level meter (a-6), a water spraying pipe (a-7), a spiral blade (a-8), a solid phase separation motor (a-9), a solid phase separation belt (a-10), and a solid phase separation outlet (a-11), wherein: The electric valve has four, which are a first solid phase separation electric valve (a-5-1), a second solid phase separation electric valve (a-5-2), a third solid phase separation electric valve (a-5-3), and a fourth solid phase separation electric valve (a-5-4); the first solid phase separation electric valve (a-5-1) is arranged at the top of the solid phase separation equipment shell (a-2) and is used for adjusting the internal gas pressure of the solid phase separation device; The extraction inlet (a-1) is arranged on one side of the solid phase separation equipment shell (a-2) and is in communication with the extraction well; The solid phase separation outlet (a-11) is arranged on the other side of the solid phase separation equipment shell (a-2), and the gas phase separation device (b) is provided with a flow meter (a-4) and a second solid phase separation electric valve (a-5-2) at the front end of the solid phase separation outlet. The filter screen has four, according to the aperture from big to small, respectively, the first filter screen (a-3-1), the second filter screen (a-3-2), the third filter screen (a-3-3), the fourth filter screen (a-3-4), for multi-stage filtration of the soil containing adsorbed organic matter, arranged in the solid phase separation equipment shell (a-2) in turn, the first filter screen (a-3-1) is adjacent to the extract inlet (a-1); The water jet pipe (a-7) has four, which are arranged behind each filter screen, and the four water jet pipes (a-7) are connected with the external water source through the third solid phase separation electric control valve (a-5-3) for spraying water to the filter screen to clean the filter screen; The spiral blade (a-8) is arranged at the bottom of the solid phase separation equipment shell (a-2), one end of the spiral blade (a-8) is provided with the fourth solid phase separation electric control valve (a-5-4) for discharging the soil, the other end of the spiral blade (a-8) is connected with the output shaft of the solid phase separation motor (a-9) through the solid phase separation belt (a-10), the spiral blade (a-8) is provided with rotating power by the solid phase separation motor (a-9) through the solid phase separation belt (a-10), and the spiral blade (a-8) rotates to discharge the soil containing adsorbed organic matter washed down through the fourth solid phase separation electric control valve (a-5-4); The liquid level meter (a-6) is used for monitoring the liquid level in the solid phase separation device, and is arranged on the side of the solid phase separation equipment shell (a-2).

3. The multi-phase extraction separation system for contaminated sites according to claim 1, wherein the gas phase separation device (b) comprises: a gas phase separation inlet (b-1), a tank body (b-2), a gas phase separation electric control valve (b-3), a gas pressure sensor (b-4), a gas phase separation liquid level meter (b-5), a gas outlet (b-6), a centrifugal pump (b-7), a check valve (b-8), and a liquid outlet (b-9), wherein: the gas phase separation inlet (b-1) and the gas outlet (b-6) are arranged on the upper end of the tank body (b-2), the gas phase separation inlet (b-1) is communicated with the solid phase separation outlet of the solid phase separation device (a), and the gas outlet (b-6) is communicated with the gas inlet of the vacuum air extraction equipment (d); the gas phase separation electric control valve (b-3) is arranged on the upper side of the tank body (b-2) and is used for adjusting the gas pressure in the tank body; the gas pressure sensor (b-4) is arranged on the upper side of the tank body (b-2) and is used for monitoring the gas pressure in the tank body; the gas phase separation liquid level meter (b-5) is arranged on the side of the tank body (b-2) and is used for monitoring the liquid level in the tank body; the bottom of the tank body (b-2) is communicated with the inlet of the centrifugal pump (b-7) through a pipeline, the outlet of the centrifugal pump (b-7) is connected with the liquid outlet (b-9), a check valve (b-8) is arranged between the outlet of the centrifugal pump (b-7) and the liquid outlet (b-9), the liquid outlet (b-9) is communicated with the mixed liquid inlet of the NAPL phase separation device (c), the centrifugal pump (b-7) is used for providing power in the liquid discharge process, and the check valve (b-8) is used for preventing liquid backflow.

4. The multi-phase extraction separation system for contaminated sites according to claim 1, wherein the rotating structure (c-5) is specifically: ​ ​ The rotating shell (c-5-2) is a circular truncated cone structure, which is narrow at the top and wide at the bottom; The rotating blade (c-5-3) is provided with a centrifugal zone inlet (c-5-7) between the top edge of the rotating blade (c-5-3) and the rotating shell (c-5-2); The rotating blade (c-5-3) is a grid structure, and is provided with a first flow channel (c-5-8), a second flow channel (c-5-9) and a third flow channel (c-5-10) between the side wall of the rotating blade (c-5-3) and the rotating shell (c-5-2), and the three flow channels are communicated in the horizontal direction through the grid of the rotating blade (c-5-3); The first bottom plate (c-5-4) is provided with a first circular hole (c-5-4-1) in the center, which is communicated with the first flow channel (c-5-8) in the rotating blade (c-5-3); an arc-shaped opening (c-5-4-2) is arranged in the middle, which is communicated with the second flow channel (c-5-9) in the rotating blade (c-5-3); and a first circular opening (c-5-4-3) is arranged at the edge, which is communicated with the third flow channel (c-5-10) in the rotating blade (c-5-3); The second bottom plate (c-5-5) is provided with a second circular hole (c-5-5-1) in the center, and a groove (c-5-5-2) is arranged around the second circular hole (c-5-5-1), the groove (c-5-5-2) is opposite to and communicated with the arc-shaped opening (c-5-4-2) of the first bottom plate (c-5-4), and then communicated with the second flow channel (c-5-9) in the rotating blade (c-5-3); and a second circular opening (c-5-5-3) is arranged at the edge, which is communicated with the first circular opening (c-5-4-3) at the edge of the first bottom plate (c-5-4), and then communicated with the third flow channel (c-5-10) in the rotating blade (c-5-3); The third bottom plate (c-5-6) is provided with a third circular hole (c-5-6-1) in the center, and a rectangular groove (c-5-6-2) is arranged at the edge of the third circular hole (c-5-6-1) in the radial direction, the rectangular groove (c-5-6-2) is communicated with the circular opening (c-5-5-3) at the edge of the second bottom plate (c-5-5), and then communicated with the third flow channel (c-5-10) in the rotating blade (c-5-3); The hole diameters of the first connecting pipe (c-5-11), the second connecting pipe (c-5-12) and the third connecting pipe (c-5-13) are arranged from small to large, wherein the first connecting pipe (c-5-11) is connected at the bottom of the first bottom plate (c-5-4) and communicated with the first center circular hole (c-5-4-1), the second connecting pipe (c-5-12) is connected at the bottom of the second bottom plate (c-5-5) and communicated with the second center circular hole (c-5-5-1), and the third connecting pipe (c-5-13) is connected at the bottom of the third bottom plate (c-5-6) and communicated with the third center circular hole (c-5-6-1); The above three connecting pipes are nested in sequence and have gaps between adjacent inner and outer walls, and sealing measures are arranged at the connection between the three connecting pipes and the bottom plate, and finally The first connecting pipe (c-5-11) is in communication with the first circular hole (c-5-4-1) in the center of the first bottom plate (c-5-4) and the first flow channel (c-5-8) in the rotating vane (c-5-3) in sequence, forming a complete flow channel, i.e. LNAPL flow channel, for discharging LNAPL; The gap between the inner wall of the second connecting pipe (c-5-12) and the outer wall of the first connecting pipe (c-5-11) forms a flow channel, and is in communication with the second circular hole (c-5-5-1) in the center of the second bottom plate (c-5-5), the groove (c-5-5-2), the arc-shaped opening (c-5-4-2) in the middle of the first bottom plate (c-5-4), and the second flow channel (c-5-9) in the rotating vane (c-5-3) in sequence, forming a complete flow channel, i.e. water flow channel, for discharging water containing dissolved organic matter; The gap between the inner wall of the third connecting pipe (c-5-13) and the outer wall of the second connecting pipe (c-5-12) forms a flow channel, and is in communication with the third circular hole (c-5-6-1) in the center of the third bottom plate (c-5-6), the rectangular groove (c-5-6-2), the second circular opening (c-5-5-3) at the edge of the second bottom plate (c-5-5), the first circular opening (c-5-4-3) at the edge of the first bottom plate (c-5-4), and the third flow channel (c-5-10) in the rotating vane (c-5-3) in sequence, forming a complete flow channel, i.e. DNAPL flow channel, for discharging DNAPL.

5. The system of claim 1, wherein the vacuum air extraction device (d) comprises a gas inlet (d-1) and a gas outlet, the gas inlet (d-1) being in communication with the gas outlet of the gas phase separation device (b), and the gas outlet being in communication with the VOC treatment device (e).

6. The system of claim 2, wherein the extraction operation comprises: When the extraction flow rate monitored by the flow meter (a-4) is lower than the set flow rate threshold during the extraction operation, the cleaning of the silt on the filter screen is started, and the specific cleaning process comprises: ​ The first solid phase separation electric control valve (a-5-1) is opened, at this time the internal pressure of the solid phase separation device (a) returns to normal, and water, air and NAPL continue to slowly enter the gas phase separation device (b), the liquid level is monitored by the solid phase separation liquid level gauge (a-6), when the liquid level is lower than the set solid phase separation liquid level threshold, the second solid phase separation electric control valve (a-5-2) is closed, the third solid phase separation electric control valve (a-5-3) and the fourth solid phase separation electric control valve (a-5-4) are opened, the external water source sprays water to the filter screen through the water spray pipe (a-7) to flush the sand, the solid phase separation motor (a-9) operates to discharge the sand containing adsorbed organic matter through the fourth solid phase separation electric control valve (a-5-4) opening by the helical blade (a-8), when the flushing time reaches the set flushing time, the third solid phase separation electric control valve (a-5-3) and the fourth solid phase separation electric control valve (a-5-4) are closed, the solid phase separation motor (a-9) stops operating, and the cleaning process is ended.

7. The contaminated site multi-phase extraction separation system of claim 3, wherein, When the extraction operation starts, the centrifugal pump (b-7) stops, the NAPL phase separation device (c) stops, and the liquid level in the tank (b-2) is monitored by the gas phase separation liquid level gauge (b-5); when the liquid level is higher than the upper limit of the set gas phase separation liquid level range, the NAPL phase separation process starts, the centrifugal pump (b-7) operates, and the NAPL phase separation device (c) operates synchronously; when the gas phase separation liquid level gauge (b-5) detects that the liquid level in the tank (b-2) is lower than the lower limit of the set gas phase separation liquid level range or the extraction operation needs to be stopped, the centrifugal pump (b-7) stops, the NAPL phase separation device (c) stops, and the NAPL phase separation process is ended.

8. The contaminated site multi-phase extraction separation system of claim 1, wherein, The LNAPL, DNAPL and water separation process includes: The NAPL phase separation motor (c-3) operates to make the rotating structure (c-5) of the NAPL phase separation device (c) rotate at high speed, water and NAPL enter the rotating structure (c-5) through the mixed liquid inlet (c-1), and the mixed liquid passes through the gap at the top edge of the rotating blade (c-5-3) to enter the centrifugal zone at the lower part of the rotating blade (c-5-3), under the action of high-speed rotation, LNAPL, DNAPL and water are separated, and LNAPL, water and DNAPL are arranged from the center of the rotating shaft to the outside in sequence; The resistivity of LNAPL is monitored by the first electrode group (c-11-1), when the resistivity reaches the set threshold of the LNAPL separation resistivity, the second NAPL phase separation electric control valve (c-7-2) is opened, and LNAPL is discharged through the LNAPL outlet (c-9); The resistivity of DNAPL is monitored by the third electrode group (c-11-3), when the resistivity reaches the set threshold of the DNAPL separation resistivity, the third NAPL phase separation electric control valve (c-7-3) is opened, and DNAPL is discharged through the DNAPL outlet (c-10); The water resistivity is monitored by the second electrode set (c-11-2), and when the water resistivity reaches a set threshold, the first NAPL phase separation electrically controlled valve (c-7-1) is opened, and the water containing dissolved organic matter is discharged through the water outlet (c-8).

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