CN116422685A - Method and device for out-of-situ restoration of oil-contaminated sites - Google Patents

Abstract

The invention discloses an ectopic repairing method and device for petroleum polluted sites, wherein the method comprises a soil ectopic repairing method and an underground water ectopic repairing method, and the soil ectopic repairing method comprises the repairing processes of screening and cleaning polluted soil, recovering floating oil, carrying out plate and frame filter pressing and carrying out plasma melting; for high-temperature oil gas generated in the plasma melting process, metal sintering dust removal, condensation spraying and sexual carbon adsorption processes are adopted, and underground water ectopic restoration is processed by adopting gravity sedimentation, air floatation, magnetic nanometer fine separation, coagulation sedimentation and two-stage sand filtration processes. The invention aims to provide an off-site restoration method for petroleum polluted site soil and groundwater, which can recycle oil products and realize resource utilization, and is used for solving the problems of poor resource utilization, long restoration time and the like in the prior restoration technology, thereby improving the restoration operation efficiency, shortening the restoration operation time and realizing the resource utilization of off-site treatment.

Description

Method and device for out-of-situ restoration of oil-contaminated sites

technical field

The invention relates to the field of remediation of soil and groundwater pollution, in particular to a method and device for ex-situ remediation of oil-contaminated sites.

Background technique

At present, soil and groundwater pollution remediation can be divided into in-situ and ex-situ remediation methods. For enterprises in production, in order to avoid the impact of in-situ repair on existing facilities such as underground pipelines and cables, ex-situ repair methods are often used. For polluted soil, dig out and backfill with good soil. For polluted soil, methods such as thermal analysis, microbial remediation, and chemical curing and stabilization are often used. Thermal desorption technology can recycle oil, but the operating cost is high, and the residue after treatment needs further resource utilization; microbial remediation technology has low treatment cost, but the remediation time is long, and it is not suitable for treating contaminated soil with high oil content; solidification Stabilization technology cannot recover oil products, and the repair effect needs time to verify, so it is not recognized by the environmental protection department. For the polluted groundwater, in order to shorten the restoration time, the polluted groundwater is often pumped to the ground for treatment, and then injected back into the ground after reaching the standard, but the treatment cost is relatively high.

Contents of the invention

The purpose of the present invention is to provide a recyclable oil product and a method and device for out-of-situ remediation of oil-contaminated sites that can realize resource utilization, which is used to solve the problems of poor resource utilization and long repair time in existing remediation technologies. In this way, the restoration operation efficiency can be improved, the restoration operation time can be shortened, the resource utilization of off-site disposal can be realized, and the comprehensive restoration of the site soil and groundwater can be realized. To achieve the above object, the present invention provides the following technical solutions:

An ex-situ remediation method of an oil-contaminated site, the ex-situ remediation method comprising a soil ex-situ remediation method and a groundwater ex-situ remediation method, wherein,

The steps of the soil heterotopic restoration method include: screening and cleaning the contaminated soil; performing plate and frame pressure filtration on the cleaned soil to form a mud cake; performing plasma melting on the mud cake to complete the heterotopic soil restoration;

The steps of the groundwater dislocation restoration method include: extracting polluted groundwater with a sealing device in a well; gravity sedimentation of the polluted groundwater to obtain preliminary purified water; the preliminary purified water is subjected to air flotation to obtain secondary purified water; Perform magnetic nano-fine separation to obtain tertiary purified water; carry out coagulation sedimentation and two-stage sand filtration on the tertiary purified water to complete the groundwater ex-situ restoration.

Preferably, said sieving and cleaning the polluted soil comprises the following steps:

Unload the polluted soil into the crusher for crushing treatment to obtain crushed polluted soil;

The broken polluted soil enters the sieve of the sieve cleaning machine for spray washing;

The broken polluted soil particles after spraying and washing enter the vibration cleaning machine to obtain small particle soil;

The small particle soil enters the screen of the vibrating cleaning machine for secondary cleaning.

Preferably, the polluted soil is squeezed and sheared by a crusher blade to obtain crushed polluted soil; the size of the crushed polluted soil is less than 10mm.

Preferably, the crushed contaminated soil enters the screen of the screening cleaning machine through a screw conveyor;

The broken polluted soil is gradually flattened with the movement of the push plate on the inner wall of the screen under the rotation of the screen before spraying;

The spraying and washing of the flattened and broken polluted soil includes steam spraying and hot water spraying, the temperature of hot water spraying is 60-95°C, the temperature of steam spraying is 120-160°C, and the pressure is 0.4-0.7MPa.

Preferably, the spraying hot water includes chemical cleaning agents; the chemical cleaning agents include: 0.02% sodium dodecylbenzenesulfonate, 0.12% sodium silicate, 0.10% sodium carbonate, and 99.76% water.

Preferably, the crushed polluted soil particles after spraying and washing enter the vibration cleaning machine to obtain small particle soils including,

The soil particles larger than the sieve hole size of the vibrating cleaning machine are sieved and fall into the screw conveyor, and are pushed out by the screw conveyor;

Soil particles smaller than the sieve size of the vibrating cleaner, together with oil and water, fall onto the sieve of the vibrating cleaner to perform secondary cleaning of the small particle soil.

Preferably, the mesh size of the cleaning machine is 0.1-0.5 mm, and the vibration frequency is 1000-1500 times/minute.

Preferably, the secondary cleaning of the small particle soil includes hot water spraying; the size of the small particle soil is 0.1-0.5mm.

Preferably, performing plate and frame press filtration on the cleaned soil to form a mud cake comprises the following steps:

Carry out degreasing treatment on the cleaned small particles to obtain mixed mud of soil and water;

The mixed mud is transported to a plate and frame filter press for squeeze filtration to form a mud cake.

Preferably, the degreasing treatment of the cleaned small particles includes,

After being cleaned by the vibration cleaner, the small particles of soil together with oil and water enter the oil collection tank, and the oil slick collector in the oil collection tank collects the oil slick on the surface of the pool;

After the oil slick is collected, the plunger pump transports the mixed mud of soil and water to the plate and frame filter press.

Preferably, the water content of the mud cake is less than 40%.

Preferably, said performing plasma melting on the mud cake comprises:

After the mud cake enters the plasma melting furnace, add additives to the mud cake, the ratio of mud cake to additive is 1:3～1:5;

The plasma melting furnace emits a plasma arc, and the organic matter in the mud cake decomposes into a high-temperature oil-gas mixture; the inorganic matter and additives in the mud cake reach a state of high-temperature melting, and finally form a vitreous crystal.

Preferably, the additive includes but is not limited to one of silicon dioxide or calcium oxide.

Preferably, the high-temperature oil-gas mixture is treated by metal sintering dust removal, condensation spraying and activated carbon adsorption processes.

Preferably, said extraction of polluted groundwater using the well sealing device comprises the following steps:

Place the sealing device in the well at the set position in the well, open the intake valve, close the exhaust valve, fill the high elastic air bag with air through the air nozzle, the air bag expands, and gradually sticks to the well wall, observe the pressure gauge, when it reaches After setting the pressure, close the intake valve, the highly elastic air bag will fit closely with the well wall, the vacuum in the well will increase, and the polluted groundwater will be extracted by the pump.

Preferably, the gravity settlement of the polluted groundwater includes the natural settlement of the polluted groundwater in the gravity settling tank, the oil phase is located in the upper part of the tank, and the sewage is located in the lower part of the tank; the oil phase enters the sewage oil tank; the sewage It is transported to the air flotation area of the air flotation device by a centrifugal pump.

Preferably, said primary purified water undergoes air flotation to obtain secondary purified water including:

The tiny oil droplets in the preliminary purified water adhere to the air bubbles in the air flotation device to form oil slick particles and float to the water surface;

The oil scraper of the air flotation device recovers the floating oil particles on the surface to the oil collection tank, and removes the oil in the water to obtain secondary purified water.

Preferably, the magnetic nano fine separation of the secondary purified water to obtain the tertiary purified water includes,

The secondary purified water enters the fine separation tank equipped with magnetic nanoparticles;

The magnetic particles are closely arranged at the oil-water interface to form a physical barrier layer, and the upper oil phase enters the oil collection tank to remove the tiny emulsified oil in the secondary purified water to obtain tertiary purified water.

Preferably, performing coagulation sedimentation and two-stage sand filtration on the three-stage purified water includes:

The three-stage purified water reacts with polyaluminum chloride coagulant to form fine flocs, and the flocs react with polyacrylamide flocculants to form flocs, and the flocs are removed by pressing to obtain the three-stage purified water after settlement; the three-stage purified water after settlement The first-grade purified water is filtered through two-stage sand filters to further remove impurities in the water and obtain restoration water.

Preferably, the coagulant coagulation is polyaluminum chloride, and the addition ratio is 10-100PPM; the flocculant is polyacrylamide, and the addition ratio is 5-50PPM; the oil content of the repair water is less than or equal to 0.1mg/L, suspended matter less than or equal to 0.1mg/L.

An ex-situ remediation device for oil-contaminated sites, the device includes: an ex-situ remediation device for oil-contaminated soil, used for remediating polluted soil; and an ex-situ remediation device for groundwater in oil-contaminated sites, used for remediating polluted groundwater.

Preferably, the ectopic remediation of soil in the oil-contaminated site includes a crusher, a screw conveyor, a sieve cleaning machine, a vibrating cleaning machine, an oil collection tank, a screw pump, a plunger pump, a plate and frame filter press, and a plasma melting machine. Furnaces and high temperature oil and gas treatment devices;

The crusher is connected with the screen of the screening cleaning machine through the screw conveyor, the vibrating cleaning machine is connected under the screening cleaning machine, the oil collecting tank is connected under the vibrating cleaning machine, the screw pump is above the oil collecting tank, and the oil collecting tank It is connected with the plate and frame filter press through the plunger pump, and the plate and frame filter press is connected with the plasma melting furnace through the screw conveyor.

Preferably, the sludge crusher is provided with a driving shaft and a driven shaft, blades with cutting edges are installed on the driving shaft and the driven shaft, and the gap between the blades is 5-10mm; the screw conveyor is made of stainless steel The material is a hollow shaftless screw conveyor.

Preferably, the sieve of the sieve cleaning machine includes evenly distributed circular holes, the diameter of the first half of the sieve is 5-7 mm, the diameter of the second half of the sieve is 3-5 mm, and the inside of the sieve is provided with Steam and hot water spray pipelines, hot water spray pipelines are provided between the outside of the screen and the shell of the screening cleaning machine, and a spiral material propulsion plate is provided on the inner wall of the screen; the sieve size of the vibrating cleaning machine is 0.1 ~0.5mm.

Preferably, the inside of the oil collection tank includes an oil floating collector; the oil floating collector includes 4 buoys, the middle of which is a suction inlet, the middle suction inlet is located at the oil-water interface, and the suction inlet is externally connected to the screw pump through the oil collection hose; The screw pump is used to collect floating oil.

Preferably, the high temperature oil and gas treatment device includes:

Metal sintering dust removal device is used to remove dust in high temperature oil and gas;

The condensing spray device is used to remove the volatile organic gases generated during the plasma melting furnace process;

Activated carbon adsorption device is used to adsorb non-condensable gas and pyrolysis gas, including carbon monoxide and hydrogen.

Preferably, the groundwater ectopic restoration device in the oil-contaminated site includes a well sealing device, a gravity settling tank, a waste oil tank, an air flotation device, an oil collection tank, a fine separation tank, a coagulation settling tank, a plate and frame filter press and two Grade sand filter tank;

Among them, the sealing device in the well is installed in the underground well to increase the vacuum in the well; the upper part of the gravity settling tank is connected to the waste oil tank through a valve, and the lower part of the gravity settling tank is connected to the air flotation device through a centrifugal pump; the upper part of the air flotation device is connected to the oil collection tank , the fine separation tank is connected under the air flotation device; the lower part of the fine separation tank is connected with the coagulation settling tank through a pump; the coagulation settling tank is connected with a two-stage sand filter tank through a plate and frame filter press.

Preferably, the sealing device in the well includes a seamless steel pipe, an air nozzle, an air pipeline, a metal baffle, a highly elastic air bag, an intake valve, an exhaust valve and a pressure gauge; wherein, the air intake valve is installed on the air pipeline , Exhaust valves, pressure gauges, air pipelines are connected to the air source of the air compressor, the metal partition is sealed and welded to the seamless steel pipe, the air nozzle is threaded to the metal partition; the upper part of the seamless steel pipe is a pagoda head structure.

Preferably, the air flotation device includes a microbubble generator; the inside of the fine separation tank includes magnetic nanoparticles; The filter diameter is 0.4~0.8mm.

Preferably, the magnetic nanoparticles are ferric oxide with a particle size of 10-20 nm.

Technical effect and advantage of the present invention:

1. The soil remediation process not only achieves the standard treatment of the soil, but also realizes the resource utilization of the soil and the maximum resource disposal;

2. After the groundwater is treated, it can be recycled as the clean water required for soil remediation, realizing water saving and consumption reduction;

3. The process chain is complete, which can realize the standard disposal and resource utilization of soil, groundwater and tail gas, and provide a feasible package solution for site contaminated soil and groundwater restoration;

4. Compared with conventional clamp fastening or tape winding methods, the well sealing device mentioned in the present invention significantly improves the vacuum degree, facilitates the adjustment of the suction port of the suction pipe in the well, and eliminates well pipe leakage to the greatest extent. Effect of gas on vacuum degree.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure pointed out in the written description, claims hereof as well as the appended drawings.

Description of drawings

Fig. 1 is a process flow chart of soil ex-situ remediation;

Figure 2 is a flow chart of the high temperature oil and gas remediation process;

Fig. 3 is the technological flow chart of groundwater dislocation restoration;

Fig. 4 is the structural diagram of the screening cleaning machine;

Figure 5a is a top view of the floating oil collector structure;

Figure 5b is a side view of the structure of the floating oil collector;

Fig. 6 is a structural diagram of a metal sintering dust removal device;

Figure 7 is a diagram of the sealing device in the well.

In the figure: 1. Seamless steel pipe; 2. Air nozzle; 3. Air pipeline; 4. Metal clapboard; 5. High elastic air bag; 6. Intake valve; 7. Exhaust valve; 8. Pressure gauge.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In order to solve the deficiencies of the prior art, the invention discloses a method and device for off-site restoration of an oil-contaminated site, which can realize comprehensive restoration of site soil and groundwater up to standards. The ectopic remediation method includes a soil ectopic remediation method and a groundwater ectopic remediation method, wherein, the steps of the soil ectopic remediation method include: sieving and cleaning the polluted soil; performing plate and frame pressure filtration on the cleaned soil to form a mud cake Carry out plasma melting to the mud cake, and complete soil heterotopic restoration; The steps of the groundwater heterotopic restoration method include: the polluted groundwater is subjected to gravity settlement to obtain preliminary purified water; the preliminary purified water is obtained through air flotation to obtain secondary purified water; The secondary purified water is subjected to magnetic nano fine separation to obtain the tertiary purified water; the tertiary purified water is subjected to coagulation sedimentation and two-stage sand filtration to complete the groundwater ex-situ restoration.

An ex-situ remediation device for oil-contaminated sites includes an ex-situ remediation device for oil-polluted soil, which is used for remediating polluted soil;

The soil dislocation restoration device for oil-contaminated sites is used for repairing contaminated soil crushers, screw conveyors, sieve cleaning machines, vibrating cleaning machines, oil collection tanks, screw pumps, plunger pumps, plate and frame filter presses, Plasma melting furnace and high-temperature oil and gas treatment device; the crusher is connected to the screen of the screening cleaning machine through the screw conveyor, the vibrating cleaning machine is connected under the screening cleaning machine, and the oil collecting tank is connected under the vibrating cleaning machine. A screw pump is installed inside the tank, and the oil collection tank is connected with a plate-and-frame filter press through a screw pump, and the plate-and-frame filter press is connected with a plasma melting furnace through a screw conveyor.

Further, the sludge crusher is provided with a driving shaft and a driven shaft, both of which are equipped with cutting blades, and the gap between the blades is 5-10 mm.

Further, the screw conveyor is made of stainless steel and is a hollow shaftless screw conveyor.

Further, as shown in Figure 4, under the drive of the screw conveyor electrode, the polluted soil enters the push plate in the feed hopper through the feed screw conveyor, and the push plate enters the push plate driven by the motor of the screening device. The sieve, the sieve of the sieve cleaning machine includes evenly distributed circular holes, the diameter of the first half of the screen is 5-7mm, the diameter of the second half of the screen is 3-5mm, and the inside of the screen is equipped with steam and Hot water spray pipeline, there is a hot water spray pipeline between the outside of the screen and the shell of the sieve cleaning machine, and a spiral material push plate is provided on the inner wall of the screen; large particle soil enters the large material screw conveyor, and small particle soil Enter the fines outlet.

Further, the mesh size of the vibration cleaning machine is 0.1-0.5mm.

Further, an oil slick collector is arranged in the oil collection tank, and the oil slick collector as shown in Figure 5 is provided with 4 buoys, the middle is a suction inlet, the middle suction inlet is located at the oil-water interface, and the oil-slick screw pump is received outside the suction inlet. .

Furthermore, the metal sintering dust removal device is used to remove dust in high temperature oil and gas;

Further, the condensing spray device is used to remove the volatile organic gases generated during the treatment process of the plasma melting furnace;

Further, the activated carbon adsorption device is used to adsorb non-condensable gas and cracked gas, including carbon monoxide and hydrogen.

Furthermore, the ectopic groundwater remediation device for oil-contaminated sites includes well sealing devices, gravity settling tanks, waste oil tanks, air flotation devices, oil collection tanks, fine separation tanks, coagulation settling tanks, plate and frame filter presses and two-stage sand Filter tank; among them, the sealing device in the well is installed in the underground well to increase the vacuum degree in the well, which is more conducive to the removal of groundwater; the upper part of the gravity settling tank is connected with the sewage tank through a valve, and the lower part of the gravity settling tank is connected with a centrifugal pump and an air flotation device Connection; the upper part of the air flotation device is connected to the oil collection tank, and the lower part of the air flotation device is connected to the fine separation tank; the lower part of the fine separation tank is connected to the coagulation settling tank through a pump; the coagulation settling tank is connected to the two-stage sand filter tank through a plate and frame filter press .

The air flotation device includes a microbubble generator; the inside of the fine separation tank includes magnetic nanoparticles; the two-stage sand filter tank has a first-stage sand filter diameter of 0.8-1.2mm, and a second-stage sand filter diameter of 0.8-1.2 mm. 0.4～0.8mm.

Further, the magnetic nanoparticles are ferric oxide, and the particle diameter is about 10-20nm.

Further, as shown in the flow chart of the soil heterotopic restoration method shown in Figure 1, after the contaminated soil is excavated, the contaminated soil is unloaded into the hopper of the crusher with a forklift, and the sludge crusher is provided with a driving shaft and a driven shaft , the driving shaft drives the driven shaft to rotate, the blades with cutting edges are installed on the driving shaft and the driven shaft, the blades move towards each other, there is a gap of 5-10mm between the blades, and the differential rotation of the driving shaft and the driven shaft The working mode realizes the extrusion and shearing of the blade to the soil. After the polluted soil is processed by a crusher, the soil is crushed to a size within 10mm. The crushed contaminated soil enters the screening and cleaning machine through the screw conveyor, as shown in Figure 4, the structure diagram of the screening and cleaning machine, the screen of the screening and cleaning machine is evenly arranged with circular small holes, and the first half of the screen is sieved. The diameter is about 5-7mm, and the diameter of the second half of the screen is about 3-5mm. There are steam and hot water spray lines inside the screen, and hot water spray lines between the outside of the screen and the shell of the sieve cleaning machine. . When the polluted soil enters the screening and cleaning machine, the motor of the screening and cleaning machine drives the screen to rotate slowly at a rotation rate of about 3 to 7 rpm. , as the pusher plate gradually flattens and moves from the feed port to the discharge port, the steam spray line and the hot water spray line in the screen spray steam and hot water respectively to the polluted soil. Next, the oil adsorbed by the polluted soil is washed out, together with the spray water and the soil particles smaller than the sieve hole, enter the vibrating cleaning machine below the sieve cleaner, and the soil particles larger than the sieve size are cleaned, and then the sieve The end of the washing machine comes out, falls into the screw conveyor, and is pushed out by the screw conveyor. Fine pieces of material, that is, small particles of soil, together with oil and water, fall onto the screen of the vibration cleaning machine. Hot water spray head for secondary cleaning of small particles of soil. After being cleaned by the vibrating cleaner, the small particles of soil, together with oil and water, enter the oil collection tank under the vibrating screen. An oil slick collector is arranged in the oil collecting tank to collect the slick oil on the surface of the tank. The oil slick collector is equipped with 4 buoys, and the middle is the suction port. The overall density of the oil slick collector is lighter than water and heavier than oil, so that the middle suction port is located at the oil-water interface, and the oil is received outside the suction port by the screw pump. Next, the floating oil on the surface of the oil collection tank is sucked into the pipeline through the suction port, and then pumped to the waste oil tank. There is a submerged screw pump in the oil collection tank. After collecting the floating oil, the plunger pump is used to transport the mixed mud of soil and water to the plate and frame filter press. Under the extrusion of the plate and frame, the solid phase is pressed by the plate and frame. The filter cloth of the filter machine is intercepted to form a mud cake, and the liquid phase is discharged through the filter cloth, thereby realizing the dehydration of the mixed mud. The moisture content of the mud cake after dehydration is about 40% or less, and the filtrate from the press filter can be transported to the groundwater treatment device for treatment . The dehydrated mud cake enters the plasma melting furnace through the screw conveyor, and glass particles such as silica are added at a ratio of 1:3 to 1:5 between the mud cake and the additive. The plasma gun heats the inert gas argon into a superheated conductive gas, ejects a plasma arc, and the temperature is about 350-600 degrees. Using the heat capacity and good thermal conductivity of the plasma arc, it breaks the chemical bonds of organic matter under the condition of oxygen isolation. It is decomposed into gas mixtures such as carbon monoxide and hydrogen, and the high-temperature oil-gas mixture enters the subsequent processing device. Under the action of ultra-high temperature, inorganic substances (minerals, heavy metals, etc.) and additives reach a high-temperature melting state, and finally form glass crystals. The leaching rate of glassy crystals is extremely low, and can be used as building materials to achieve zero landfill and resource utilization.

长度为1200～2500mm。该装置采用下行式进气设计，高温油气从除尘装置下端进入，从每个滤芯表层进入滤芯空腔内，穿透滤芯，油气中的灰尘在滤芯表层实现有效拦截过滤后，油气从装置顶部经由油气出口出，进入下一级喷淋装置。金属烧结滤芯可过滤0.1μm以上的灰尘，过滤后高温油气粉尘含量低于10mg/Nm3，从而实现高温油气的有效除尘。金属烧结除尘装置设有氮气反吹，当滤芯内外压差大于0.6kpa时，启动氮气反吹，每根滤芯上部设有氮气反吹喷嘴，喷嘴采用拉瓦尔管结构，以提高喷嘴出口氮气速度接近音速，氮气以高速脉冲形式对滤芯内部进行反吹，反吹氮气压力0.6～0.8MPa，反吹间隔根据运行情况设定，可为0.5～3分钟，以清除滤芯内外截留的灰渣。金属烧结除尘装置底部设有两级出渣，上部卸灰阀打开，下部卸灰阀关闭时，灰渣掉入料仓内，料仓设有物位计，当料仓内灰渣较多达到设定物位时，上部卸灰阀关闭，下部卸灰阀打开，灰渣落入灰渣收集袋内，从而保证除尘装置滤芯内的油气不会随灰渣溢出。另外，为了保证顺利出料，在两级卸灰阀上端设有氮气吹扫，每次卸灰完毕，进行氮气吹扫，以清除干净灰渣。因等离子熔融炉处理过程中，可能会有挥发性有机物未分解直接进入后端装置，为去除此类有机气体，经除尘后的高温油气进入冷凝喷淋装置，与冷凝水直接接触，经水喷淋冷却至50℃以下，高温油气中的有机物冷凝下来，和水进入油水分离槽，进而实现油水分离。不凝气和裂解产生的一氧化碳、氢气等进入活性炭吸附罐，经活性炭吸附后达标排放。Furthermore, during the treatment process of the plasma melting furnace, the high-temperature oil and gas generated are processed by metal sintering dust removal, condensation spraying and activated carbon adsorption. The flow chart of the high-temperature oil and gas repair method is shown in Figure 2. The high-temperature oil and gas first enter the metal sintered dust removal device, and 60 to 85 metal sintered filter elements are evenly arranged in the device. The filter element is a cylindrical structure, hollow, and the diameter is

The length is 1200-2500mm. The device adopts a downward air intake design. The high-temperature oil and gas enter from the lower end of the dust removal device, enter the cavity of the filter element from the surface of each filter element, and penetrate the filter element. After the dust in the oil and gas is effectively intercepted and filtered on the surface of the filter element, the oil and gas pass through The oil and gas exits and enters the next level of spraying device. The metal sintered filter element can filter dust above 0.1μm, and the dust content of high-temperature oil and gas after filtration is less than 10mg/Nm3, so as to realize effective dust removal of high-temperature oil and gas. The metal sintering dust removal device is equipped with nitrogen blowback. When the pressure difference between the inside and outside of the filter element is greater than 0.6kpa, the nitrogen blowback is started. The upper part of each filter element is equipped with a nitrogen blowback nozzle. The nozzle adopts a Laval tube structure to increase the nitrogen speed at the nozzle outlet. At the speed of sound, the nitrogen gas backflushes the inside of the filter element in the form of high-speed pulses. The nitrogen pressure of the backflush is 0.6-0.8MPa. The backflush interval can be set according to the operating conditions, which can be 0.5-3 minutes to remove the ash trapped inside and outside the filter element. There are two stages of slag discharge at the bottom of the metal sintering dust removal device. When the upper ash unloading valve is opened and the lower ash unloading valve is closed, the ash will fall into the silo. The silo is equipped with a level gauge. When setting the material level, the upper ash unloading valve is closed, the lower ash unloading valve is opened, and the ash falls into the ash collection bag, so as to ensure that the oil and gas in the filter element of the dust removal device will not overflow with the ash. In addition, in order to ensure smooth discharge, nitrogen purge is provided at the upper end of the two-stage ash unloading valve. After each ash unloading, nitrogen purge is carried out to remove clean ash. During the treatment process of the plasma melting furnace, there may be volatile organic compounds that are not decomposed and directly enter the back-end device. In order to remove such organic gas, the high-temperature oil gas after dust removal enters the condensation spray device, directly contacts with the condensed water, and is sprayed with water. After cooling down to below 50°C, the organic matter in the high-temperature oil and gas condenses and enters the oil-water separation tank with water to realize oil-water separation. Non-condensable gas and carbon monoxide and hydrogen produced by pyrolysis enter the activated carbon adsorption tank, and are discharged up to the standard after being adsorbed by activated carbon.

Further, the function of the soil breaker is to realize the homogenization of the soil before sieving and cleaning treatment, so as to avoid the appearance of large particles of soil and affect the cleaning effect. When the soil contains a lot of pebbles and gravel, considering the impact of the wear of the crusher blade, it can directly enter the screening and cleaning machine through the screw conveyor without passing through the crusher.

Further, the screw conveyor is made of stainless steel in consideration of material properties, and is a hollow shaftless screw conveyor.

Further, in the sieve cleaning machine, the hot water spraying temperature is 60-95°C, the steam spraying temperature is 120-160°C, and the pressure is 0.4-0.7MPa. Spray pipes are provided with spray ports every 15-30cm.

Further, the sieve cleaning machine can add chemical cleaning agents to the spraying hot water, so as to facilitate the separation of oil from the polluted soil. The composition and ratio of the chemical cleaning agents are: 0.02% sodium dodecylbenzenesulfonate, 0.12% sodium silicate, 0.10% sodium carbonate, and 99.76% water.

Further, for the oil slick collector, Fig. 5a is a top view of the structure of the oil slick collector. It can be seen from the figure that the oil slick collector includes 4 buoys, with a suction port in the middle. According to Fig. 5b, it is a side view of the structure of the oil slick recovery machine. , the middle suction port is located at the oil-water interface, and an oleophilic and hydrophobic film made of metal can be added at the suction port, so that the oil slick can flow to the suction port smoothly, while the water is effectively blocked and difficult to enter, thereby reducing the loss of water in the collected oil slick Inhalation volume.

Further, the suction port is externally connected to the screw pump through the oil collection hose; the screw pump is used to collect floating oil.

The oil slick tank is equipped with an air flotation pipeline, and the tiny air bubbles generated by the air flotation machine lift the slick oil in the water to the surface to recover the slick oil to the greatest extent and ensure that the oil content of the mud entering the filter press is reduced to a minimum.

Furthermore, if the plasma melting furnace is screened and cleaned at the front end, the soil can meet the restoration standard, and it does not need to enter the plasma melting furnace for further treatment. In the plasma melting furnace, a paddle type stirring device is provided to fully mix the mud cake and the glass body and avoid coking of the furnace wall. In the plasma melting furnace, there is an aluminum silicate heat-resisting refractory material.

Further, the filter element of the metal sintered dust removal device is a metal porous filter structure, which can be made of stainless steel 316L, 304L, 310, high-temperature alloy and other materials according to the processing temperature requirements, after metal melting, atomization, screening, rolling, high-temperature vacuum Processed by sintering and other processes, it can withstand 400-800 °C. The filter element of the metal sintering dust removal device has a wall thickness of 0.7 mm to 2.5 mm and a filtration accuracy of 0.1 um to 100 um.

Further, as shown in Figure 6, the structural diagram of the metal sintering dust removal device, the metal sintering dust removal device includes a pressure difference changer, a temperature changer, a metal sintering filter element, a dust removal cylinder, a blowback nitrogen inlet, an oil and gas inlet, and an oil and gas outlet , nitrogen purge port, slag outlet and ash discharge valve, etc. The filter element of the dust removal device and the tube sheet are threaded, which can withstand high temperature and high pressure, and avoid the tight seal caused by gaskets and other methods. The ash discharge valve of the metal sintering dust removal device is a rice-shaped structure, which prevents the oil and gas in the cavity from volatilizing while discharging the ash. The affiliated metal sintering dust removal device is equipped with 5 to 7 filter areas, and the pipeline in each area is equipped with a solenoid valve. It adopts the process mode of continuous filtration and regular online partition back blowing. When single area back blowing, the rest of the areas filter normally. .

Furthermore, if the high-temperature oil and gas produced by the plasma melting furnace contains more ash, a cyclone dust removal device can be installed in front of the metal sintering dust removal device to remove larger particle size ash and reduce the load on the metal sintering dust removal device. Because the main components of high-temperature oil and gas are combustible gases such as carbon monoxide and hydrogen, torch combustion devices can also be used instead of activated carbon adsorption.

As shown in Figure 3, the groundwater dislocation repair method uses the sealing device in the well to extract the polluted groundwater; the polluted groundwater is subjected to gravity settlement to obtain primary purified water; the primary purified water is obtained through air flotation to obtain secondary purified water; The purified water is subjected to magnetic nano-fine separation to obtain tertiary purified water; the tertiary purified water is subjected to coagulation sedimentation and two-stage sand filtration to complete the heterogeneous restoration of groundwater.

Furthermore, the polluted groundwater is pumped to the ground through vacuum pumps and diaphragm pumps through well sealing devices and other suction equipment, first enters the gravity settling tank, and naturally settles in the settling tank. Cut to the waste oil tank, the sewage in the lower part of the buffer tank is transported to the air flotation area of the air flotation device by the centrifugal pump. The air flotation device is equipped with a micro-bubble generator to form highly dispersed micro-bubbles in the air. The diameter of the bubbles ranges from 20 to 40um. The oil scraper installed on the upper part of the air flotation device recovers the floating oil on the surface to the oil collection tank, further realizing the removal of oil in the water. The secondary purified water after air flotation treatment flows to the fine separation tank by itself. The separation tank is equipped with magnetic nanoparticles. The two sides of the surface of the particles have hydrophilicity and lipophilicity respectively. In the barrier layer, the upper oil phase enters the oil collection tank through the upper overflow port of the fine separation tank, so as to realize the removal of the micro-emulsified oil in the sewage. The three-stage purified water in the lower part of the fine separation tank is pumped to the coagulation settling tank, and polyaluminum chloride (PAC) coagulant is added to the tank first. Under the action of the agent, the fine suspended matter in the sewage gathers to form a fine Then add polyacrylamide (PAM) flocculant to further aggregate the flocs and sink to the bottom of the tank, pump them out to the plate and frame filter press for pressure filtration, so as to remove impurities such as suspended solids in the water. The treated three-stage purified water enters the two-stage sand filter tank, and the suspended solids in the water are trapped on the surface of the filter medium, and are filtered through the two-stage sand filter to further remove impurities in the water. After this process, the effluent can reach an oil content of ≤0.1mg/l and a suspended solid of ≤0.1mg/l, which can be used as screening and cleaning water in soil remediation to realize the recycling of water resources.

Further, the magnetic nanoparticles are Fe ₃ O ₄ with a particle diameter of about 10-20 nm.

Further, in the coagulation settling tank, the dosing ratio of polyaluminum chloride (PAC) is 10-100PPM, and the dosing ratio of polyacrylamide (PAM) is 5-50PPM. It is adjusted due to the different proportions of suspended solids and oil in water. If the suspended matter in the sewage is very low, this treatment step can be skipped.

Further, in the two-stage sand filter tank, the first-stage sand filter has a filter diameter of 0.8-1.2 mm, and the second-stage sand filter has a filter diameter of 0.4-0.8 mm. If the suspended matter in the sewage is very low, this treatment step can also be skipped.

Further, in the two-stage sand filter tank, when the dirt interception amount on the surface of the filter medium reaches the set value for backwashing, the equipment starts to perform automatic backwashing operations.

For the pollution of groundwater depth below 8 meters, submersible pumps can be used to extract groundwater to the surface.

Furthermore, when the vacuum pump is used to suck the groundwater, in order to ensure the sealing in the well, improve the vacuum degree in the well, and be more conducive to the removal of the groundwater, a sealing device in the well is provided. As shown in Figure 7, the sealing device in the well includes a seamless steel pipe 1, an air nozzle 2, an air pipeline 3, a metal partition 4, a highly elastic air bag 5, an intake valve 6, and an exhaust valve 7 and gauge 8.

Among them, the air inlet valve 6, the exhaust valve 7, and the pressure gauge 8 are installed on the air pipeline 3, the air pipeline 3 is connected with the air source of the air compressor, the metal partition 4 is sealed and welded with the seamless steel pipe 1, and the air nozzle 2 Connect with the metal partition 4 threads. The upper part of the seamless steel pipe is a pagoda head structure, which is convenient for connecting the suction hose. First, connect all components as shown in Figure 7. After placing the device at the set position in the well, open the intake valve 6, close the exhaust valve 7, fill air into the highly elastic air bag 5 through the air nozzle 2, the air bag expands, and gradually sticks to the well wall of the suction well. Observe the pressure gauge 8, when the set pressure is reached, close the intake valve 6, at this time, the highly elastic air bag 5 is closely attached to the well wall of the suction well, and the sealing effect in the well can be achieved. When it is necessary to readjust the suction liquid level in the well, close the intake valve 6, open the exhaust valve 7, the air in the highly elastic air bag 5 is discharged, the air bag shrinks, and gradually separates from the well wall of the suction well, observe the pressure gauge 8, when After the pressure returns to zero, the highly elastic air bag 5 is separated from the well wall of the suction well, and can move up and down to the set position in the well.

On the basis of the above technical solutions, the following improvements can also be made.

Further, the highly elastic airbag is bonded to the metal partition with hot vulcanized glue.

Further, the wall thickness of the highly elastic airbag is about 2-3 mm, and it is made of rubber material.

Furthermore, when the air is not filled, there should be a distance of 2-10 mm between the highly elastic air bag and the well wall.

Further, the suction pipe connected with the seamless steel pipe can be provided with a scale, so as to adjust the position of the sealing device in the well pipe.

Further, the sealing device can be placed at a position above the liquid level in the well, or at a position below the liquid level to realize vacuum suction of the liquid phase. It can be adjusted according to soil pollution and remediation requirements. The general principle is to minimize the suction space in the well.

Further, the device does not limit the pipe diameter specification.

It should be emphasized that those skilled in the art should understand that in the embodiments of the present invention, each step is continuous and cooperates with each other to form a whole, and there are related in-out pipelines between each processing flow and even each equipment. And import and export, to ensure the smooth progress of the soil and groundwater remediation process. In the case of separating the whole process and adopting a certain step alone, the effect is far less than the technical effect obtained by the overall process.

Finally, it should be noted that: the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still It is possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. within the spirit and principles of the present invention shall be included in the within the protection scope of the present invention.

Claims (30)

1. An oil-contaminated site ectopic remediation method, characterized in that, the ectopic remediation method includes a soil ectopic remediation method and a groundwater ectopic remediation method, wherein, The steps of the soil heterotopic restoration method include: screening and cleaning the contaminated soil; performing plate and frame pressure filtration on the cleaned soil to form a mud cake; performing plasma melting on the mud cake to complete the heterotopic soil restoration; The steps of the groundwater dislocation restoration method include: extracting polluted groundwater with a sealing device in a well; gravity sedimentation of the polluted groundwater to obtain preliminary purified water; the preliminary purified water is subjected to air flotation to obtain secondary purified water; Perform magnetic nano-fine separation to obtain tertiary purified water; carry out coagulation sedimentation and two-stage sand filtration on the tertiary purified water to complete the groundwater ex-situ restoration. 2. A method for ex-situ remediation of oil-contaminated sites according to claim 1, wherein said screening and cleaning the polluted soil comprises the following steps: Unload the polluted soil into the crusher for crushing treatment to obtain crushed polluted soil; The broken polluted soil enters the sieve of the sieve cleaning machine for spray washing; The broken polluted soil particles after spraying and washing enter the vibration cleaning machine to obtain small particle soil; The small particle soil enters the screen of the vibrating cleaning machine for secondary cleaning. 3. a kind of oil-contaminated site ex-situ restoration method according to claim 2, is characterized in that, The polluted soil is squeezed and sheared by a crusher blade to obtain crushed polluted soil; the size of the crushed polluted soil is less than 10mm. 4. a kind of oil-contaminated site ectopic remediation method according to claim 2, is characterized in that, The crushed polluted soil enters the screen of the screening cleaning machine through a screw conveyor; The broken polluted soil is gradually flattened with the movement of the push plate on the inner wall of the screen under the rotation of the screen before spraying; The spraying and washing of the flattened and broken polluted soil includes steam spraying and hot water spraying, the temperature of hot water spraying is 60-95°C, the temperature of steam spraying is 120-160°C, and the pressure is 0.4-0.7MPa. 5. A method for remediating oil-contaminated sites in situ according to claim 4, characterized in that, The spraying hot water includes chemical cleaning agents; The chemical cleaning agents include: 0.02% sodium dodecylbenzenesulfonate, 0.12% sodium silicate, 0.10% sodium carbonate, and 99.76% water. 6. A method for remediating oil-contaminated sites in situ according to claim 2, wherein the sprayed and washed broken polluted soil particles enter a vibrating cleaning machine to obtain small particle soils, comprising: The soil particles larger than the sieve hole size of the vibrating cleaning machine are sieved and fall into the screw conveyor, and are pushed out by the screw conveyor; Soil particles smaller than the sieve size of the vibrating cleaner, together with oil and water, fall onto the sieve of the vibrating cleaner to perform secondary cleaning of the small particle soil. 7. A method for ex situ remediation of oil-contaminated sites according to claim 6, characterized in that, The mesh size of the vibration cleaning machine is 0.1-0.5mm, and the vibration frequency is 1000-1500 times/min. 8. A method for ex situ remediation of oil-contaminated sites according to claim 6, characterized in that: The secondary cleaning of the small particle soil includes hot water spraying; The size of the small particle soil is 0.1-0.5mm. 9. A method for ex-situ remediation of oil-contaminated sites according to claim 1, wherein said performing plate and frame press filtration on the cleaned soil to form a mud cake comprises: Carry out degreasing treatment on the cleaned small particles to obtain mixed mud of soil and water; The mixed mud is transported to a plate and frame filter press for squeeze filtration to form a mud cake. 10. A method for ex-situ remediation of oil-contaminated sites according to claim 9, wherein said degreasing treatment of the cleaned small particles comprises: After being cleaned by the vibration cleaner, the small particles of soil together with oil and water enter the oil collection tank, and the oil slick collector in the oil collection tank collects the oil slick on the surface of the pool; The plunger pump transports the mixed slurry of soil and water from which oil slicks have been removed to the plate and frame filter press. 11. A method for ex-situ remediation of oil-contaminated sites according to claim 9, characterized in that: The moisture content of the mud cake is less than 40%. 12. A method for ex-situ remediation of oil-contaminated sites according to claim 1, wherein said plasma melting the mud cake comprises: After the mud cake enters the plasma melting furnace, add additives to the mud cake, the ratio of mud cake to additive is 1:3～1:5; The plasma melting furnace emits a plasma arc, and the organic matter in the mud cake decomposes into a high-temperature oil-gas mixture; the inorganic matter and additives in the mud cake reach a state of high-temperature melting, and finally form a vitreous crystal. 13. A method for ex situ remediation of oil-contaminated sites according to claim 12, characterized in that: The additive includes but not limited to one of silicon dioxide or calcium oxide. 14. A method for ex situ remediation of oil-contaminated sites according to claim 12, characterized in that: The high-temperature oil-gas mixture is treated by metal sintering dust removal, condensation spraying and activated carbon adsorption processes. 15. A method for ex-situ remediation of oil-contaminated sites according to claim 1, characterized in that: The extraction of polluted groundwater by means of sealing devices in wells includes: Place the sealing device in the well at the set position in the well, open the intake valve (6), close the exhaust valve (7), fill the high elastic air bag (5) with air through the air nozzle (2), the air bag expands, and gradually Adhere to the well wall, observe the pressure gauge (8), when the set pressure is reached, close the intake valve (6), the highly elastic air bag (5) is closely attached to the well wall, the vacuum degree in the well is increased, and the pollution is extracted by the pump groundwater. 16. The method for ex-situ remediation of oil-contaminated sites according to claim 1, wherein the gravity settlement of the polluted groundwater comprises: The polluted groundwater settles naturally in the gravity settling tank, the oil phase is located in the upper part of the tank, and the sewage is located in the lower part of the tank; the oil phase enters the waste oil tank; the sewage is transported to the air flotation area of the air flotation device by a centrifugal pump. 17. The method for ex-situ restoration of oil-contaminated sites according to claim 1, wherein said primary purified water is subjected to air flotation to obtain secondary purified water comprising: The tiny oil droplets in the preliminary purified water adhere to the air bubbles in the air flotation device to form oil slick particles and float to the water surface; The oil scraper of the air flotation device recovers the floating oil particles on the surface to the oil collection tank, and removes the oil in the water to obtain secondary purified water. 18. The method for ex-situ remediation of oil-contaminated sites according to claim 1, wherein said performing magnetic nano-fine separation on secondary purified water to obtain tertiary purified water comprises: The secondary purified water enters the fine separation tank equipped with magnetic nanoparticles; The magnetic particles are closely arranged at the oil-water interface to form a physical barrier layer, and the upper oil phase enters the oil collection tank to remove the tiny emulsified oil in the secondary purified water to obtain tertiary purified water. 19. The method for ex-situ remediation of oil-contaminated sites according to claim 1, wherein said coagulation and sedimentation of the three-stage purified water and two-stage sand filtration include: Tertiary purified water reacts with polyaluminum chloride coagulant to form fine flocs, flocs react with polyacrylamide flocculants to form flocs, and press filter to remove flocs to obtain tertiary purified water after settlement; After settling, the three-stage purified water is filtered through two-stage sand filter to further remove impurities in the water and obtain restoration water. 20. A method for ex-situ remediation of oil-contaminated sites according to claim 19, characterized in that, The coagulant coagulation is polyaluminum chloride, and the addition ratio is 10-100PPM; The flocculant is polyacrylamide, and the addition ratio is 5-50PPM; The oil content of the restoration water is less than or equal to 0.1 mg/L, and the suspended matter is less than or equal to 0.1 mg/L. 21. An ex-situ remediation device for oil-contaminated sites using the method according to any one of claims 1-20, characterized in that the device comprises: The ex-situ remediation device for oil-contaminated site soil is used to remediate polluted soil; The groundwater ex situ remediation device for oil-contaminated sites is used to remediate polluted groundwater. 22. An off-site restoration device for oil-contaminated sites according to claim 21, characterized in that: The soil ectopic remediation of the oil-contaminated site includes a crusher, a screw conveyor, a sieve cleaning machine, a vibration cleaning machine, an oil collection tank, a screw pump, a plunger pump, a plate and frame filter press, a plasma melting furnace and a high temperature Oil and gas treatment equipment; The crusher is connected with the screen of the screening cleaning machine through the screw conveyor, the vibrating cleaning machine is connected under the screening cleaning machine, the oil collecting tank is connected under the vibrating cleaning machine, the screw pump is above the oil collecting tank, and the oil collecting tank It is connected with the plate and frame filter press through the plunger pump, and the plate and frame filter press is connected with the plasma melting furnace through the screw conveyor. 23. An off-site restoration device for oil-contaminated sites according to claim 22, characterized in that: The sludge crusher is provided with a driving shaft and a driven shaft, blades with cutting edges are installed on the driving shaft and the driven shaft, and the gap between the blades is 5-10 mm; The screw conveyor is made of stainless steel and is a hollow shaftless screw conveyor. 24. An off-site restoration device for oil-contaminated sites according to claim 22, characterized in that: The sieve of the sieve cleaning machine includes evenly distributed circular holes, the diameter of the first half of the sieve is 5-7mm, the diameter of the second half of the sieve is 3-5mm, and the inside of the sieve is provided with steam and heat Water spray pipeline, a hot water spray pipeline is installed between the outside of the screen and the casing of the screen cleaning machine, and a spiral material push plate is provided on the inner wall of the screen; The mesh size of the vibrating cleaning machine is 0.1-0.5 mm. 25. An off-site restoration device for oil-contaminated sites according to claim 22, characterized in that: The inside of the oil collection tank includes a floating oil collector; The oil slick collector includes 4 buoys, the middle is the suction port, the middle suction port is located at the oil-water interface, and the suction port is externally connected to the screw pump through the oil collecting hose; The screw pump is used to collect floating oil. 26. The off-site remediation device for oil-contaminated sites according to claim 22, wherein the high-temperature oil and gas treatment device comprises: Metal sintering dust removal device is used to remove dust in high temperature oil and gas; The condensing spray device is used to remove the volatile organic gases generated during the plasma melting furnace process; Activated carbon adsorption device is used to adsorb non-condensable gas and pyrolysis gas, including carbon monoxide and hydrogen. 27. An off-site restoration device for oil-contaminated sites according to claim 21, characterized in that: The groundwater dislocation restoration device in the oil-contaminated site includes a well sealing device, a gravity settling tank, a waste oil tank, an air flotation device, an oil collection tank, a fine separation tank, a coagulation settling tank, a plate and frame filter press, and a two-stage sand filter Can; Among them, the sealing device in the well is installed in the underground well to increase the vacuum in the well; the upper part of the gravity settling tank is connected to the waste oil tank through a valve, and the lower part of the gravity settling tank is connected to the air flotation device through a centrifugal pump; the upper part of the air flotation device is connected to the oil collection tank , the fine separation tank is connected under the air flotation device; the lower part of the fine separation tank is connected with the coagulation settling tank through a pump; the coagulation settling tank is connected with a two-stage sand filter tank through a plate and frame filter press. 28. An off-site restoration device for oil-contaminated sites according to claim 27, characterized in that: The sealing device in the well includes a seamless steel pipe (1), an air nozzle (2), an air pipeline (3), a metal partition (4), a highly elastic air bag (5), an air intake valve (6), an exhaust Valve (7) and pressure gauge (8); Air intake valve (6), exhaust valve (7) and pressure gauge (8) are installed on the air pipeline (3), the air pipeline (3) is connected with the air source of the air compressor, and the metal partition (4) is connected with the seamless The steel pipe (1) is sealed and welded, and the air nozzle (3) is threaded with the metal partition (4); The upper part of the seamless steel pipe is a pagoda head structure. 29. An off-site restoration device for oil-contaminated sites according to claim 27, characterized in that: The air flotation device includes a microbubble generator; The interior of the fine separation tank includes magnetic nanoparticles; In the two-stage sand filter tank, the primary sand filter diameter is 0.8-1.2 mm, and the secondary sand filter diameter is 0.4-0.8 mm. 30. The off-site remediation device for oil-contaminated sites according to claim 27, characterized in that: The magnetic nanoparticles are ferric oxide, and the particle diameter is 10-20nm.

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