Polluted site multiphase extraction and separation system

Abstract

The invention provides a polluted site multiphase extraction and separation system, which comprises a solid phase separation device, a gas phase separation device, an NAPL phase separation device, vacuum pumping equipment and a VOC treatment device, and is used for separating silt containing adsorbed organic matters, gas containing volatile organic matters, water containing soluble organic matters, light non-aqueous phase liquid (LNAPL) and heavy non-aqueous phase liquid (DNAPL). According to the invention, multiphase extraction and multiphase separation are integrated, and extraction and separation can be synchronously realized, so that the remediation efficiency of organic pollution of soil and the pollutant treatment efficiency are remarkably improved, and popularization and application of the system are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation of contaminated sites, and in particular to a multiphase extraction and separation system for contaminated sites. Background Art

[0002] The accelerated advancement of urbanization and the rapid development of the chemical industry have produced a large amount of organic waste, resulting in an increase in the number of contaminated sites year by year. Therefore, 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 heavy non-aqueous phase liquids (DNAPL) according to density. At present, the remediation technologies for contaminated sites are mainly multiphase extraction, chemical oxidation, solidification stabilization, biodegradation, etc. Among them, multiphase extraction technology uses a vacuum method to extract underground contaminated water, gas and NAPL to the ground to reduce the content of organic pollutants in soil and groundwater. Multiphase extraction technology has been widely used due to its ability to quickly control and simultaneously repair underground pollution. At present, my country's multiphase extraction equipment is in the initial stage of development. Existing multiphase extraction equipment can usually only extract underground pollutants and transport them to hazardous waste treatment agencies, making it difficult to achieve separation and treatment on-site. Summary of the invention

[0003] In view of the shortcomings of existing multiphase extraction equipment, the present invention provides a multiphase extraction and separation system for contaminated sites.

[0004] The technical solution of the present invention:

[0005] A multiphase extraction and separation system for a contaminated site, comprising: a solid phase separation device a, a gas phase separation device b, a NAPL phase separation device c, a vacuum exhaust device d, and a VOC treatment device e, wherein:

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

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

[0008] 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;

[0009] The vacuum exhaust equipment d provides negative pressure for the multiphase extraction construction, extracts the gas containing volatile organic compounds in the tank of the gas phase separation device b, and discharges it after purification by the VOC treatment device e.

[0010] Due to the adoption of the above scheme, the beneficial effects of the present invention are:

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

[0012] 2. In order to separate the extracts, solid phase separation devices, gas phase separation devices and NAPL phase separation devices were developed to separate the sediment containing adsorbed organic matter, the gas containing volatile organic matter, the water containing dissolved organic matter, LNAPL and DNAPL for further processing. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0015] Figure 3 This is one of the schematic diagrams of the appearance structure of the solid phase separation device.

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

[0017] Figure 5 Schematic diagram of the internal structure of the solid phase separation device.

[0018] Figure 6 Schematic diagram of the gas phase separation device structure.

[0019] Figure 7 Schematic diagram of the internal structure of the NAPL phase separation device.

[0020] Figure 8 Schematic diagram of the rotating structure assembly in the NAPL phase separation device.

[0021] Fig. 9 A cross-sectional view of the rotating structure in the NAPL phase separation device.

[0022] Fig.10 for Fig. 9Schematic diagram of the cross-sectional structure in A-A', B-B', C-C', D-D', E-E', and F-F' directions.

[0023] Fig.11 It is a schematic diagram of the process flow of the system of the present invention.

[0024] Reference numerals:

[0025] Solid phase separation device a, including: extract inlet a-1, solid phase separation equipment 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 level meter a-6, water spray pipe a-7, spiral 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, including: gas phase separation inlet b-1, gas phase separation tank b-2, gas phase separation electric control valve b-3, air pressure sensor b-4, gas phase separation level gauge b-5, gas outlet b-6, centrifugal pump b-7, check valve b-8, liquid outlet b-9;

[0027] NAPL phase separation device c, including: mixed liquid inlet c-1, equipment 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 The rotating structure c-5 includes: 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 first center circular hole c-5-4-1, an arc-shaped opening c-5-4-2, a first circular opening c-5-4-3, a second bottom plate c-5-5, a second center circular hole c-5-5-1, a groove c-5-5-2, a second circular opening c-5-5-3, a third bottom plate c-5-6, a third center circular hole c-5-6-1, a rectangular groove c-5-6-2, a centrifugal zone inlet c-5-7, a first flow channel c-5-8, a second flow channel c-5-9, a third flow channel c-5-10, a first connecting pipe c-5-11, a second connecting pipe c-5-12, and a third connecting pipe c-5-13;

[0028] Vacuum pumping equipment d, wherein: gas inlet d-1;

[0029] VOC treatment device e. DETAILED DESCRIPTION

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

[0031] like Figure 1 , Figure 2 As shown, a multiphase extraction and separation system for a contaminated site includes: a solid phase separation device a, a gas phase separation device b, a NAPL phase separation device c, a vacuum exhaust device d, and a VOC treatment device e, wherein:

[0032] The solid phase separation device a is used to separate the sediment containing adsorbed organic matter in the extract, and the extract after the sediment is separated 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 matter in the extract, and the water and non-aqueous phase liquid (NAPL) containing dissolved organic matter are pumped into the NAPL phase separation device c;

[0034] 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);

[0035] The vacuum exhaust equipment d provides negative pressure for the multiphase extraction construction, extracts the gas containing volatile organic compounds in the tank of the gas phase separation device b, and discharges it after purification by the VOC treatment device e.

[0036] The solid phase separation device a is used to separate the sediment containing adsorbed organic matter in the extract, and includes: an extract inlet a-1, a solid phase separation device housing a-2, a filter screen, a flow meter a-4, an electric control valve, a solid phase separation 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. Figure 3 , Figure 4 , Figure 5 As shown, where:

[0037] There are four electric control valves, namely the first solid phase separation electric control valve a-5-1, the second solid phase separation electric control valve a-5-2, the third solid phase separation electric control valve a-5-3, and the fourth solid phase separation electric control valve a-5-4; the first solid phase separation electric control valve a-5-1 is arranged on the top of the solid phase separation equipment housing a-2, and is used to adjust the internal air pressure of the solid phase separation device;

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

[0039] The solid phase separation outlet a-11 is arranged on the other side of the solid phase separation equipment housing a-2, and a flow meter a-4 and a second solid phase separation electric control 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 filter screens, which are 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 descending order of aperture, and are used for multi-stage filtration of sediment containing adsorbed organic matter. They are uniformly arranged in sequence in the solid phase separation equipment housing a-2, and the first filter screen a-3-1 is adjacent 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 electric control valve a-5-3 to spray water to clean the filter screen;

[0042] The spiral blade a-8 is arranged at the bottom of the solid phase separation equipment housing a-2, and a fourth solid phase separation electric control valve a-5-4 is arranged at one end of the spiral blade a-8 for removing sediment, and 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, and the solid phase separation motor a-9 provides rotational power to the spiral blade a-8 through the solid phase separation belt a-10, and the spiral blade a-8 rotates to discharge the washed sediment containing adsorbed organic matter through the fourth solid phase separation electric control valve a-5-4;

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

[0044] The gas phase separation device b is used to separate the gas containing volatile organic matter in the extract, and includes: a gas phase separation inlet b-1, a tank body b-2, a gas phase separation electric control valve b-3, a pressure sensor b-4, a gas phase separation 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. Figure 6 As shown, where:

[0045] The gas phase separation inlet b-1 and the gas outlet b-6 are arranged at the upper end of the tank body b-2, the gas phase separation inlet b-1 is communicated with the solid phase separation outlet a-11 of the solid phase separation device a, the gas outlet b-6 is communicated with the gas inlet of the vacuum pumping equipment d, and the liquid outlet b-9 is communicated with the mixed liquid inlet c-1 of the c-NAPL phase separation device;

[0046] The gas phase separation electric control valve b-3 is arranged on the upper side of the tank b-2 and is used to adjust the gas pressure inside the tank;

[0047] The air pressure sensor b-4 is arranged on the upper side of the tank b-2 and is used to monitor the air pressure inside the tank;

[0048] The gas phase separation level meter b-5 is arranged on the side of the tank b-2 and is used to monitor the liquid level in the tank;

[0049] The bottom of the tank body b-2 is connected to the inlet of the centrifugal pump b-7 through a pipeline, and the outlet of the centrifugal pump b-7 is connected to the liquid outlet b-9. A check valve b-8 is provided 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 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 includes: a mixed liquid inlet c-1, an equipment housing 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, such as Figure 7 , Figure 8 , Fig. 9 , Fig.10 As shown, where:

[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 in the gas phase separation device b;

[0052] The rotating structure c-5 is installed in the equipment housing 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 to the separation pipe c-6; the rotating structure c-5 is used for high-speed rotation to separate water containing dissolved organic matter, light non-aqueous phase liquid (LNAPL) and heavy non-aqueous phase liquid (DNAPL) from each other, and includes a bearing c-5-1, a rotating housing 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 inserted into the groove of the first bottom plate c-5-4, and the upper part of the rotating blade c-5-3 is inserted 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 inside the rotating structure. Two bearings c-5-1 are respectively installed on the upper and lower parts of the whole, thus forming a rotating structure c-5.

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

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

[0055] A centrifugal zone inlet c-5-7 is provided between the top edge of the rotating blade c-5-3 and the rotating housing c-5-2;

[0056] The rotating blade c-5-3 is a grid structure, and a first flow channel c-5-8 and a second flow channel c-5-9 are arranged inside. A third flow channel c-5-10 is arranged between the rotating blade c-5-3 and the side wall of the rotating shell c-5-2. The three flow channels are interconnected in the horizontal direction through the grid of the rotating blade c-5-3.

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

[0058] The second bottom plate c-5-5: a second circular hole c-5-5-1 is provided in the center, and a circle of grooves c-5-5-2 is provided along the second circular hole c-5-5-1, and the grooves c-5-5-2 are opposite to and connected with the arc-shaped opening c-5-4-2 of the first bottom plate c-5-4, and further connected with the second flow channel c-5-9 inside the rotating blade c-5-3; a second circular opening c-5-5-3 is provided on the edge, and the second circular opening c-5-5-3 is connected with the first circular opening c-5-4-3 at the edge of the first bottom plate c-5-4, and further connected with the third flow channel c-5-10 inside the rotating blade c-5-3;

[0059] The third bottom plate c-5-6: a third circular hole c-5-6-1 is provided in the center, and a rectangular groove c-5-6-2 is provided radially outwardly at the edge of the third circular hole c-5-6-1, and 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 further communicated with the third flow channel c-5-10 inside the rotating blade c-5-3;

[0060] The apertures of the first connecting tube c-5-11, the second connecting tube c-5-12, and the third connecting tube c-5-13 are from small to large, wherein: the first connecting tube 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 tube 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 tube 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 there is a gap between the adjacent inner and outer walls. The connection between the three connecting pipes and the bottom plate is provided with sealing measures. Finally, there are:

[0062] The first connecting pipe c-5-11 is connected in sequence 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 inside the rotating blade c-5-3 to form a complete flow channel, namely, the LNAPL flow channel, for removing the 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 is sequentially connected with the second circular hole c-5-5-1 at 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 inside the rotating blade c-5-3, forming a complete flow channel, i.e., a 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 connected in sequence 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 inside the rotating blade c-5-3 to form a complete flow channel, namely, the DNAPL flow channel, for discharging the DNAPL.

[0065] The separation pipe c-6 includes three channel outlets, which are respectively connected to the three complete flow channels (LNAPL flow channel, water, and DNAPL flow channel) of the rotating structure c-5, and then the separation pipe c-6 is divided into three outputs: 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 control 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 control 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 control 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 respectively arranged on the first bottom plate c-5-4, the second bottom plate c-5-5, and the third bottom plate c-5-6, and are used to measure the liquid resistivity to monitor the separation purity (LNAPL and DNAPL have high resistivity, and water containing dissolved organic matter has low resistivity). The three groups of electrodes are respectively powered by three groups of power supply slip rings, namely 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 embodiment, 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 housing c-2, and its output shaft is connected to the rotating structure c-5 through the NAPL phase separation belt c-4. The NAPL phase separation motor c-3 provides power to the rotating structure c-5 through the NAPL phase separation belt c-4.

[0068] The principle of flow separation between water and NAPL is:

[0069] After water and NAPL enter the rotating structure c-5 through the mixed liquid inlet c-1, the mixed liquid enters the centrifugal zone at the bottom of 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 make the rotating structure c-5 rotate at high speed. The mixed liquid inside the centrifugal zone is driven by the rotating blade c-5-3 to rotate at high speed. Since the density of LNAPL is less than that of water, the LNAPL in the mixed liquid will transfer to the center of the rotating axis c-13, that is, the LNAPL will transfer to the first flow channel c-5-8 through the grille of the rotating blade c-5-3. Similarly, due to DNAP L density is greater than that of water, and DNAPL in the mixed liquid will move away from the center of the rotating axis c-13, that is, LNAPL will be transferred to the third flow channel c-5-10 through the grille of the rotating blade c-5-3, and water will be located between LNAPL and DNAPL. Therefore, LNAPL, DNAPL and water are separated, and from the center of the rotating axis c-13 to the outside, they are LNAPL, water, and DNAPL in order. The inclined side wall of the rotating shell c-5-2 helps DNAPL to gather at the outer edge of the bottom of the centrifugal zone. The center of the rotating blade c-5-3 has a conical structure with the top of the cone facing downward, which helps LNAPL to gather at the center of the rotating axis at the bottom of the centrifugal zone.

[0070] Compared with water, LNAPL and DNAPL have higher resistivity. The resistivity of LNAPL at this position is monitored by the first electrode group c-11-1. When the resistivity reaches the resistivity setting threshold for separating LNAPL, the second NAPL phase separation electric control valve c-7-2 opens, and LNAPL passes through the LNAPL flow channel and is discharged from the LNAPL outlet c-9; similarly, the resistivity of DNAPL is monitored by the third electrode group c-11-3. When the resistivity reaches the resistivity setting threshold for separating DNAPL, the third NAPL phase separation electric control valve c-7-3 opens, and DNAPL passes through the DNAPL flow channel and is discharged from the DNAPL outlet c-10; the resistivity of water is monitored by the second electrode group c-11-2. When the resistivity reaches the resistivity setting threshold for separating water, the first NAPL phase separation electric control valve c-7-1 opens, and water containing dissolved organic matter passes through the water flow channel and is discharged from the water outlet c-8.

[0071] The vacuum pumping equipment d provides negative pressure for multiphase extraction construction, and 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 separation device b, and the gas outlet is connected to the VOC treatment device e. The vacuum pumping equipment d extracts the gas containing volatile organic compounds in the tank b-2 of the gas phase separation device b, and discharges it after purification by the VOC treatment device e.

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

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

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

[0075] When in use, the extract inlet a-1 of the solid phase separation device a is connected to 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 to an external water source.

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

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

[0078] Step 2: Start extraction.

[0079] 2.1: The vacuum suction device d is in operation, and cooperates with the gas phase separation electric control valve b-3 to extract the air in the tank b-2 of the gas phase separation device b to reach the set extraction negative pressure range. Under the action of vacuum pressure, the extract containing pollutants such as water, air, sediment and NAPL 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 multi-stage filtration of filters with decreasing pore sizes in the solid phase separation device a (the first filter a-3-1, the second filter a-3-2, the third filter a-3-3, and the fourth filter a-3-4), the sediment containing adsorbed organic matter remains on the filter, and water, air and NAPL enter the gas phase separation device b.

[0081] After the equipment has been running for a certain period of time, the filter screen is blocked by sediment, 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, the sediment on the filter screen begins to be cleaned. The cleaning process is as follows:

[0082] The first solid phase separation electric control valve a-5-1 is opened to return the interior of the solid phase separation device a to normal pressure. At this time, 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 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, and the external water source sprays water to the filter screen through the water spray pipe a-7 to wash the sediment. The solid phase separation motor a-9 is operated. The spiral blade a-8 discharges the mud and sand containing the adsorbed organic matter through the opening of the fourth solid-phase separation electric-controlled valve a-5-4. When the flushing time reaches the set flushing time, the third solid-phase separation electric-controlled valve a-5-3 and the fourth solid-phase separation electric-controlled valve a-5-4 are closed, and the solid-phase separation motor a-9 stops running, thus ending the cleaning process. After the cleaning process, if it is necessary to continue the extraction operation, the states of each electric-controlled valve and the solid-phase separation motor a-9 are set to the states at the beginning of the above-mentioned extraction operation, and the extraction operation is continued.

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

[0084] When the gas phase separation 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 level range, the centrifugal pump b-7 and the NAPL phase separation device c start to operate, and the LNAPL, DNAPL and water are separated according to the aforementioned water and NAPL phase separation diversion principle; when the gas phase separation 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 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 ends.

[0085] Step 3: End the extraction.

[0086] After the extraction operation is completed, the vacuum exhaust equipment d is turned off, and the gas phase separation electric control valve b-3 is opened to return the inside of the tank b-2 to normal pressure, and the system stops running.

[0087] The above description is only a description of the preferred embodiments of the present application, and is not intended to limit the scope of the present application. Any changes or modifications made by any person skilled in the art based on the above disclosed technical contents shall be deemed as equivalent effective embodiments and shall fall within the scope of protection of the technical solution of the present application.

Claims

1. A multiphase extraction and separation system for contaminated sites, characterized in that: include: Solid phase separation device (a), gas phase separation device (b), NAPL phase separation device (c), vacuum pumping equipment (d), VOC treatment device (e), wherein: The solid phase separation device (a) is used to separate the sediment containing adsorbed organic matter in the extract, and the extract after the sediment is separated is transported to the gas phase separation device (b); The gas phase separation device (b) is used to separate the gas containing volatile organic matter in the extract, and the water and non-aqueous phase liquid NAPL containing dissolved organic matter are pumped into the NAPL phase separation device (c); The NAPL phase separation device (c) is used to separate water and non-aqueous phase liquid NAPL containing dissolved organic matter into water, light non-aqueous phase liquid LNAPL and heavy non-aqueous phase liquid DNAPL; The vacuum exhaust equipment (d) provides negative pressure for the multiphase extraction construction, extracts the gas containing volatile organic compounds in the tank of the gas phase separation device (b), and the extracted gas is purified by the VOC treatment device (e) before being discharged.

2. A multiphase extraction and separation system for contaminated sites as claimed in claim 1, characterized in that: The solid phase separation device (a) comprises: an extract inlet (a-1), a solid phase separation device housing (a-2), a filter screen, a flow meter (a-4), an electric control valve, a solid phase separation 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), wherein: There are four electric control valves, namely the first solid phase separation electric control valve (a-5-1), the second solid phase separation electric control valve (a-5-2), the third solid phase separation electric control valve (a-5-3), and the fourth solid phase separation electric control valve (a-5-4); the first solid phase separation electric control valve (a-5-1) is arranged on the top of the solid phase separation equipment housing (a-2) and is used to adjust the internal air pressure of the solid phase separation device; The extract inlet (a-1) is arranged on one side of the solid phase separation device housing (a-2) and is connected to the extraction well; The solid phase separation outlet (a-11) is arranged on the other side of the solid phase separation equipment housing (a-2), and a flow meter (a-4) and a second solid phase separation electric control valve (a-5-2) are provided at the front end of the solid phase separation outlet of the gas phase separation device (b); There are four filter screens, which are respectively 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 descending order of aperture, and are used for multi-stage filtration of sediment containing adsorbed organic matter, and are uniformly arranged in sequence in the housing (a-2) of the solid phase separation device, and the first filter screen (a-3-1) is adjacent to the extract inlet (a-1); There are four water spray pipes (a-7), which are arranged behind each filter screen respectively. The four water spray pipes (a-7) are connected to an external water source through a third solid phase separation electric control valve (a-5-3) to spray water to clean the filter screen; The spiral blade (a-8) is arranged at the bottom of the solid phase separation equipment housing (a-2), one end of the spiral blade (a-8) is provided with a fourth solid phase separation electric control valve (a-5-4) for removing sediment, the other end of the spiral blade (a-8) is connected to the output shaft of the solid phase separation motor (a-9) through a 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), and the spiral blade (a-8) rotates to discharge the washed sediment containing adsorbed organic matter through the fourth solid phase separation electric control valve (a-5-4); The liquid level meter (a-6) is used to monitor the liquid level in the solid phase separation device and is arranged on the side of the solid phase separation equipment housing (a-2).

3. A multiphase extraction and separation system for contaminated sites as claimed in claim 1, characterized in that: 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 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), wherein: A gas phase separation inlet (b-1) and a gas outlet (b-6) are arranged at 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 pumping device (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 to adjust the gas pressure inside the tank body; The air pressure sensor (b-4) is arranged on the upper side of the tank body (b-2) and is used to monitor the air pressure inside 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 to monitor the liquid level in the tank body; The bottom of the tank body (b-2) is connected to the inlet of the centrifugal pump (b-7) through a pipeline, the outlet of the centrifugal pump (b-7) is connected to 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 connected to the mixed liquid inlet of the NAPL phase separation device (c), the centrifugal pump (b-7) is used to provide power during the discharge process, and the check valve (b-8) is used to prevent the liquid from flowing back.

4. A multiphase extraction and separation system for contaminated sites as claimed in claim 1, characterized in that: The NAPL phase separation device (c) comprises: a mixed liquid inlet (c-1), an equipment housing (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 at the upper end of the rotating structure (c-5), and the mixed liquid inlet (c-1) is connected to the liquid outlet of the gas phase separation device (b); The rotating structure (c-5) is installed in the equipment housing (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) includes a bearing (c-5-1), a rotating housing (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 housing (c-5-2) and the first bottom plate (c-5- 4) A groove is provided, the lower part of the rotating blade (c-5-3) is inserted into the groove of the first bottom plate (c-5-4), and the upper part of the rotating blade (c-5-3) is inserted 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 inside the rotating structure. Two bearings (c-5-1) are respectively installed on the upper and lower parts of the whole, so as to form a rotating structure (c-5); The separation pipe (c-6) is divided into three outputs: LNAPL is discharged downward through the separation pipe (c-6) and discharged from the LNAPL outlet (c-9) through the second NAPL phase separation electric control valve (c-7-2); water containing dissolved organic matter is discharged to the right through the separation pipe (c-6) and discharged from the water outlet (c-8) through the first NAPL phase separation electric control valve (c-7-1); DNAPL is discharged to the left through the separation pipe (c-6) and discharged from the DNAPL outlet (c-10) through the third NAPL phase separation electric control 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 respectively arranged on the first bottom plate (c-5-4), the second bottom plate (c-5-5), and the third bottom plate (c-5-6), and the three groups of electrodes are respectively powered by three groups of power supply slip rings, namely 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 housing (c-2), and its output shaft is connected to the rotating structure (c-5) through the NAPL phase separation belt (c-4). The NAPL phase separation motor (c-3) provides power to the rotating structure (c-5) through the NAPL phase separation belt (c-4).

5. A multiphase extraction and separation system for contaminated sites as claimed in claim 4, characterized in that: The rotating structure (c-5) is specifically: The rotating shell (c-5-2) is a truncated cone structure, narrow at the top and wide at the bottom; A centrifugal zone inlet (c-5-7) is provided 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) and a second flow channel (c-5-9) inside. A third flow channel (c-5-10) is provided between the rotating blade (c-5-3) and the side wall of the rotating shell (c-5-2). The three flow channels are interconnected in the horizontal direction through the grid of the rotating blade (c-5-3); The first bottom plate (c-5-4): a first circular hole (c-5-4-1) is provided in the center, communicating with the first flow channel (c-5-8) inside the rotating blade (c-5-3); an arc-shaped opening (c-5-4-2) is provided in the middle, communicating with the second flow channel (c-5-9) inside the rotating blade (c-5-3); a first circular opening (c-5-4-3) is provided at the edge, communicating with the third flow channel (c-5-10) inside the rotating blade (c-5-3); The second bottom plate (c-5-5): a second circular hole (c-5-5-1) is provided at the center, and a circle of grooves (c-5-5-2) is provided along the second circular hole (c-5-5-1), the grooves (c-5-5-2) are opposite to and communicated with the arc-shaped opening (c-5-4-2) of the first bottom plate (c-5-4), and further communicated with the second flow channel (c-5-9) inside the rotating blade (c-5-3); a second circular opening (c-5-5-3) is provided at the edge, the second circular opening (c-5-5-3) is communicated with the first circular opening (c-5-4-3) at the edge of the first bottom plate (c-5-4), and further communicated with the third flow channel (c-5-10) inside the rotating blade (c-5-3); The third bottom plate (c-5-6): a third circular hole (c-5-6-1) is provided at the center, a rectangular groove (c-5-6-2) is provided radially outwardly at the edge of the third circular hole (c-5-6-1), and 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 further communicated with the third flow channel (c-5-10) inside the rotating blade (c-5-3); The apertures of the first connecting tube (c-5-11), the second connecting tube (c-5-12), and the third connecting tube (c-5-13) are from small to large, wherein: the first connecting tube (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 tube (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 tube (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); The above three connecting pipes are nested in sequence and there is a gap between the adjacent inner and outer walls. The connection between the three connecting pipes and the bottom plate is provided with sealing measures. Finally, there are: The first connecting pipe (c-5-11) is connected in sequence with the first circular hole (c-5-4-1) at the center of the first bottom plate (c-5-4) and the first flow channel (c-5-8) inside the rotating blade (c-5-3) to form a complete flow channel, namely, an LNAPL flow channel, for removing 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 sequentially connected 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) inside the rotating blade (c-5-3), forming a complete flow channel, i.e., a 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 connected in sequence 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) inside the rotating blade (c-5-3), to form a complete flow channel, namely the DNAPL flow channel, for discharging the DNAPL.

6. A multiphase extraction and separation system for contaminated sites as claimed in claim 1, characterized in that: The vacuum pumping equipment (d) comprises a gas inlet (d-1) and a gas outlet, the gas inlet (d-1) is connected to the gas outlet of the gas phase separation device (b), and the gas outlet is connected to the VOC treatment device (e).

7. A multiphase extraction and separation system for contaminated sites as claimed in claim 2, characterized in that: During the extraction operation, when the extraction flow rate monitored by the flow meter (a-4) is lower than the set flow rate threshold, the filter screen starts to be cleaned of sediment. The specific cleaning process includes: The first solid-phase separation electric control valve (a-5-1) is opened, and the interior of the solid-phase separation device (a) returns to normal pressure, wherein water, air and NAPL continue to slowly enter the gas phase separation device (b), and the liquid level is monitored by 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, and 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, and the external water The source sprays water to the filter screen through the water spray pipe (a-7) to flush the sediment, and the solid phase separation motor (a-9) runs, and the sediment 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, 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, and the solid phase separation motor (a-9) stops running, ending the cleaning process.

8. A multiphase extraction and separation system for contaminated sites as claimed in claim 3, characterized in that: 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 body (b-2) is monitored by the gas phase separation liquid level meter (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) runs, and the NAPL phase separation device (c) runs synchronously; 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 ends.

9. A contaminated site multiphase extraction and separation system as claimed in claim 4, characterized in that: The LNAPL, DNAPL and water separation process includes: The NAPL phase separation motor (c-3) is operated to make the rotating structure (c-5) of the NAPL phase separation device (c) rotate at a high speed, and 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) and enters the centrifugal area below the rotating blade (c-5-3). Under the action of high-speed rotation, LNAPL, DNAPL and water are separated, and from the center of the rotating shaft to the outside, they are LNAPL, water, and DNAPL in order; The resistivity of the LNAPL is monitored by the first electrode group (c-11-1), and when the resistivity reaches a set resistivity threshold for separating the LNAPL, the second NAPL phase separation electric control valve (c-7-2) is opened, and the LNAPL is discharged through the LNAPL outlet (c-9); The resistivity of the DNAPL is monitored by the third electrode group (c-11-3), and when the resistivity reaches a set resistivity threshold for separating the DNAPL, the third NAPL phase separation electric control valve (c-7-3) is opened, and the DNAPL is discharged through the DNAPL outlet (c-10); The resistivity of water is monitored by the second electrode group (c-11-2). When the resistivity set threshold of the separated water is reached, the first NAPL phase separation electric control valve (c-7-1) opens, and the water containing dissolved organic matter is discharged through the water outlet (c-8).

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