CN209439181U - Organic Contaminated Soil Purification Device - Google Patents

Abstract

The utility model discloses an organic contaminated soil purifier. The organic contaminated soil purification apparatus described above comprises: the gas infrared heater comprises a heating cavity, a conveying belt penetrating through the heating cavity and an infrared heating furnace; the inlet of the gas suction component is communicated with the top of the heating cavity; a reactor filled with a granular or honeycomb first catalyst, the reactor having a gas inlet and a gas outlet, the gas inlet of the reactor communicating with the outlet of the gas suction means; the catalytic absorption tower comprises an air inlet section, a filler section and a spraying section from bottom to top in sequence, a gas outlet of the reactor is communicated with the air inlet section of the catalytic absorption tower, the air inlet section of the catalytic absorption tower is used for containing absorption liquid, the absorption liquid is mixed with a second catalyst, the filler section of the catalytic absorption tower is provided with an adsorption filler, and the spraying section of the catalytic absorption tower is provided with a spraying pipe. Organic contaminated soil purifier, repair effect is good, efficient, investment and working costs are lower.

Description

Organic Contaminated Soil Purification Device

technical field

The utility model relates to the technical field of soil pollution treatment, in particular to a device for purifying organic polluted soil.

Background technique

Before the contaminated soil can be reused, the contaminated soil needs to be pretreated. The purpose is to remove various pollutants contained in the contaminated soil, so as to avoid future pollution and even damage to human health.

The current methods for treating organically polluted soil generally include surface excavation, chemical rinsing, and adding stabilizers to remove pollutants on the surface of the polluted soil, but these methods have the following defects: 1. The volatilized polluting gas in the process of soil remediation or excavation has not been collected and treated. Even if it is collected and treated, the combustion process is often used, resulting in high investment and operating costs. 2. Most of the washing water is not treated, or the treatment efficiency is low, which is easy to cause secondary pollution. 3. The remediation process of contaminated soil is often carried out intermittently, and rarely treated continuously, so the remediation speed is relatively slow. 4. Catalytic combustion is also used to purify volatile gases, but preheating is required to cause excessive energy consumption. 5. The decomposition speed of pollutants is slow, and the repair effect is not good. 6. The added stabilizer cannot completely eliminate the pollution, and the pollutants will be released slowly in the future.

Soil Vapor Extraction (SVE) has been widely used as an important soil remediation technology in production practice due to its high efficiency, and has been listed as a "revolutionary technology" by the US Environmental Protection Agency (EPA) for its effectiveness and extensiveness. It is divided into in situ SVE and ectopic SVE. The advantages of in-situ SVE are that the equipment is easy to operate, no excavation is required, the soil structure is not damaged, groundwater treatment is taken into account, and operators are not exposed to pollutants. However, the gas phase extraction technology also has the following disadvantages: the processing time varies with the concentration of pollutants in the soil, and the processing results are greatly affected by the soil type and soil layer, and the processing time is relatively long.

In contrast, ex-situ SVE technology can overcome the shortcomings of in-situ SVE to the greatest extent. Its basic principle is to simply screen the contaminated soil first to remove pebbles and coarse particle components, and then place the screened soil in the In the above-ground sealing system with anti-seepage and simple filtrate collection, and establish a ventilation system inside the soil pile, by providing a suitable sealed negative pressure vacuum environment and a suitable temperature and humidity environment, the air extraction device will remove pollutants from the soil Separation and purification of exhaust gas through the exhaust gas treatment system. Ultimately achieve the purpose of removing most of the volatile organic pollutants in the soil, reduce the concentration of pollutants below the target value of soil remediation, and realize the discharge after the exhaust gas is purified, and discharge the percolation water after collection and treatment. The ex-situ SVE technology is suitable for the treatment of soil containing organic volatile substances, and the restoration effect is better when the soil type is sandy and other conditions with good permeability. The ectopic SVE technology has the following advantages: it can effectively remove volatile organic pollutants in the soil, the treatment cycle is generally 1-3 months, the cycle is shorter, the operating cost is lower than similar technologies, the subsequent tail gas treatment is simple, and the tail gas treatment The system can avoid secondary pollution and has little impact on the environment and human health.

However, regardless of in-situ SVE or ex-situ SVE technology, when the soil fine particle content is high and the water content is high, the restoration effect is quite limited, and the restoration time will be longer, and the restoration cost will increase accordingly. In addition, when the soil organic matter content is high, the removal efficiency of SVE technology will also decrease. Moreover, when SVE technology treats clay soil, the strong adsorption of clay will affect the release of organic matter, so the treatment effect on clay soil is poor. In addition, the organic waste gas generated by SVE treatment needs to be further treated by biological methods and other methods, which makes the equipment occupy a large area and the treatment effect is not stable.

Utility model content

Based on this, it is necessary for the utility model to provide an organic polluted soil purification device with good restoration effect, high restoration efficiency, no need for further treatment, and low investment and operating costs.

In order to realize the purpose of the utility model, the utility model adopts the following technical solutions:

A device for purifying organic polluted soil, comprising:

A gas-fired infrared heater, the gas-fired infrared heater comprising a heating cavity, a conveyor belt passing through the heating cavity, and an infrared heating furnace providing infrared radiation for the soil on the conveyor belt;

a gas suction part, the inlet of the gas suction part communicates with the top of the heating cavity;

A reactor, the reactor is filled with a granular or honeycomb-shaped first catalyst, the reactor has a gas inlet and a gas outlet, and the gas inlet of the reactor communicates with the outlet of the gas suction component;

A catalytic absorption tower, the catalytic absorption tower includes an air intake section, a packing section and a spray section from bottom to top, the gas outlet of the reactor is connected to the air intake section of the catalytic absorption tower, and the inlet section of the catalytic absorption tower The gas section is used to contain the absorption liquid, the absorption liquid is mixed with the second catalyst, the packing section of the catalytic absorption tower is equipped with adsorption packing, and the spray section of the catalytic absorption tower is provided with a spray pipe.

The above-mentioned organic polluted soil purification device, combined with infrared radiation, low-temperature catalytic combustion and catalytic absorption technology, can quickly restore various organic polluted soils, and is not affected by soil moisture content, whether it is clay or ordinary soil, The above methods can be used to quickly repair, and the application range is wide. The combined repair can effectively avoid pollution rebound without further treatment, greatly reducing investment, operation costs and post-maintenance costs; making full use of gas preheating without auxiliary heating and The heat released by preheating, gas blowing and catalytic combustion can increase the temperature of the subsequent absorption liquid, accelerate the catalytic decomposition of organic matter, and will not produce secondary pollutants such as dioxin.

In some of the embodiments, the device for purifying organic polluted soil also includes a soil excavation part, an air collecting hood is arranged above the soil excavating part, and the air collecting hood communicates with an air blowing part, and the air blowing The component communicates with the infrared heating furnace, and is used for blowing the VOC gas volatilized at the soil excavation point into the infrared heating furnace.

In some of the embodiments, the device for purifying organic polluted soil further includes a crusher, and the crusher is connected to the soil excavation component through a conveying device.

In some of these embodiments, the reactor is connected to the oxidizing agent container or the reducing agent container.

In some of the embodiments, the catalytic absorption tower is connected to the oxidant container or the reducing agent container or the high-efficiency absorbent container.

In some embodiments, when the oxidant container or the reductant container or the high-efficiency absorbent container is a gas container, the oxidant container or the reductant container or the high-efficiency absorbent container is connected to the gas inlet section of the catalytic absorption tower.

In some embodiments, when the oxidant container or the reducing agent container or the high-efficiency absorbent container is a liquid container, the oxidant container or the reducing agent container or the high-efficiency absorbent container is connected to the spray pipe.

In some embodiments, the adsorption filler is one or more of ceramic filler, graphene sponge, metal organic framework or adsorption resin.

In some of these embodiments, the first catalyst is activated carbon, zeolite, ceramic or silicon carbide loaded with metal or metal oxide.

In some embodiments, the second catalyst is an oxide of one or more metals in Mn, Co, Fe, Zn, Cu, Mo, Mg or Al.

Description of drawings

Fig. 1 is the structural representation of the organic polluted soil purifying device described in a preferred embodiment of the present invention;

Fig. 2 is a schematic structural view of an organic polluted soil purification device according to another preferred embodiment of the present invention.

Detailed ways

In order to facilitate understanding of the utility model, the utility model will be described more fully below in conjunction with the accompanying drawings. However, the invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present utility model more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of this invention. The terminology used in the description of the utility model herein is only for the purpose of describing specific embodiments, and is not intended to limit the utility model.

Embodiment one

The present embodiment provides a method for purifying organically polluted soil, comprising the steps of:

Put the soil in an infrared radiation environment, the radiated infrared rays penetrate into the soil, heat the soil to blow off the organic matter adsorbed by the soil, and generate high-temperature VOC gas;

The high-temperature VOC gas is transferred to the reactor equipped with a granular or honeycomb first catalyst, and the VOC gas undergoes an oxidation reaction on the surface of the first catalyst through its own heat to remove part of the VOC gas;

The unreacted VOC gas in the reactor enters the catalytic absorption tower, and the adsorption packing is installed in the catalytic absorption tower. The bottom of the catalytic absorption tower is equipped with an absorption liquid, and the absorption liquid is mixed with a second catalyst. Under the action of the second catalyst, the VOC gas Generate organic acids with good water solubility and dissolve in the absorption liquid of the catalytic absorption tower.

Before the soil is placed in the infrared radiation environment, it also includes the step of breaking the soil into 1mm-10mm particles, so that the infrared radiation can penetrate into the soil more thoroughly. The soil is excavated by the excavator, and then the excavated soil is transported to the crusher for crushing by the conveying equipment. If there is no crushing process, the excavated soil is directly transported to the infrared radiation environment through the conveying equipment.

The infrared radiation environment uses a porous ceramic plate as the combustion furnace head, injecting gas (such as LNG, etc.) to burn to generate infrared radiation to heat, dry and keep the soil warm. The infrared radiation emitted by the burner during combustion has strong penetrating power. And it can excite water molecules to resonate, which can evenly penetrate the heat into the core depth of the soil, ensure uniform heating effect, and improve heating quality and drying efficiency. Since the infrared burner is completely pre-mixed with air during combustion, it ensures complete combustion, thereby reducing pollutant emissions.

Blowing components can be installed at the soil excavation point to collect volatilized VOC gas at the excavation point, so that it can be injected into the infrared radiation environment. Gas consumption. Specifically, an air collecting hood is arranged above the excavation point, and the air collecting hood communicates with the blowing part. Setting up a gas collecting hood can prevent part of the VOC gas from volatilizing into the air during excavation.

The stripping time of the soil in the infrared radiation environment is 1min-60min, that is, the time for the soil to pass through the infrared radiation environment is 1min-60min, which is selected according to the type of contaminated soil, or according to the degree of contamination of the soil.

The VOC gas undergoes low-temperature catalytic combustion in the reactor containing the first catalyst to generate vibrationally excited state products. Catalytic combustion is a complete oxidation reaction of fuel on the surface of the catalyst. During the catalytic combustion reaction, the reactants form low-energy surface free radicals on the surface of the catalyst, generate vibrationally excited products, and release energy in the form of infrared radiation. While the reaction is completely carried out, the selectivity of the catalyst is used to effectively suppress the occurrence of side reactions that generate toxic and harmful substances, and basically no or very little pollutants such as NOx, CO, and HC are produced. Traditional catalytic combustion requires an external heating source and preheating to about 300°C. This scheme makes full use of the high temperature generated by the front-end infrared radiation environment, and the volatilized organic matter is rapidly decomposed on the surface of the first catalyst at a relatively low temperature of 150°C-250°C. The process does not require additional The heat source also does not need to be preheated. For complex organic substances such as halogenated hydrocarbons and polycyclic aromatic hydrocarbons, the temperature is controlled to be less than 200°C to prevent the formation of harmful substances such as dioxins. The temperature of the VOC gas in the reactor is 150°C-250°C. The temperature of the VOC gas in the infrared radiation environment is 200°C-300°C, and the temperature after entering the reactor is 150°C-250°C.

The residence time of VOC gas in the reactor is 0.5s-3s. The first catalyst is activated carbon, zeolite, ceramic or silicon carbide loaded with metal or metal oxide.

An oxidizing agent or a reducing agent can also be added into the reactor to accelerate the catalytic oxidation or catalytic reduction speed of the VOC gas in the reactor. The oxidizing agent is, for example, a strong oxidizing agent such as ozone gas or hydrogen peroxide, and the reducing agent is sodium sulfite, sodium thiosulfate, ferrous sulfate, or the like. The reducing agent can be added to the reactor in advance according to the type of pollutants, and the ozone gas and VOC gas can be added to the reactor at the same time.

The catalytic absorption tower uses the principle of similar compatibility between liquid absorption liquid and VOC exhaust gas to achieve the purpose of treating VOC exhaust gas. By setting adsorption materials, catalysts, and oxidizing agents (or reducing agents), hydrophobic VOCs are catalyzed and oxidized ( Or catalytic reduction) is an organic acid substance with good water solubility, which uses absorption to avoid environmental pollution by exhaust gas. When the temperature of the absorbing liquid rises, the catalytic rate will be accelerated. The catalytic absorption tower is equipped with spraying facilities such as circulating pumps, water pipes and nozzles. It also makes full use of the blown-off VOC gas and the heat released by catalytic combustion to increase the temperature of the absorbing liquid in the catalytic absorption tower and accelerate the catalytic decomposition of organic matter.

The adsorption filler is preferably one or more of ceramic fillers, graphene sponges, metal-organic frameworks or adsorption resins. The second catalyst is one or more metal oxides in Mn, Co, Fe, Zn, Cu, Mo, Mg or Al, and the above catalysts participate in the reaction, which can improve the reaction speed and efficiency. The second catalyst added to the catalytic absorption tower can also promote the decomposition of the added oxidant ozone, so as to avoid secondary pollution.

The oxidant, reducing agent or high-efficiency absorbent can be added into the spray pipe of the catalytic absorption tower, and the oxidant, reducing agent or high-efficiency absorbent is sprayed into the catalytic absorption tower together with water to accelerate the oxidation or reduction. The oxidizing agent is, for example, a strong oxidizing agent such as ozone gas or hydrogen peroxide, and the reducing agent is sodium sulfite, sodium thiosulfate, ferrous sulfate, or the like.

The above method of purifying organic polluted soil, combined with infrared radiation, low-temperature catalytic combustion and catalytic absorption technology, can quickly restore various organic polluted soils, and is not affected by the moisture content of the soil, whether it is clay or ordinary soil, The above methods can be used to quickly repair, with a wide range of applications, without adding or adding less absorbent throughout the process, without adjusting the pH value, and will not increase the salinity of the repaired soil or bring in new substances. This combination of repairs can effectively avoid Pollution bounces back without further treatment, greatly reducing investment, operating costs, and post-maintenance costs; making full use of gas preheating without auxiliary heating and preheating, the heat released by blowing off gas and catalytic combustion can increase the temperature of the subsequent absorption liquid and accelerate The speed of catalytic decomposition of organic matter will not produce secondary pollutants such as dioxins; the above-mentioned equipment can be operated continuously, with high production efficiency and easy operation.

Please refer to Fig. 1, the utility model protects a kind of organic pollution soil purification device 100, and it comprises crusher 10, gas infrared heater 20, gas suction part 30, reactor 40 and catalytic absorption tower 50, and crusher 10 is close to The inlet end of the gas infrared heater 20 is provided; the gas infrared heater 20 includes a heating cavity 22, a conveyor belt 21 for transporting soil through the heating cavity 22, and an infrared heating system that provides infrared radiation for the soil on the conveyor belt 21. Furnace 23; the inlet of gas suction part 30 is communicated with the top of heating chamber 22, and the reactor 40 is filled with granular or honeycomb first catalyst 41, and reactor 40 has gas inlet 42 and gas outlet 43, and reactor 40 The gas inlet 42 of the gas suction part 30 is connected to the outlet of the gas suction part 30, so that the VOC gas extracted by the gas suction part 30 enters the reactor 40 for reaction; the catalytic absorption tower 50 is divided into an inlet section 51, a packing section 52 and The spray section 53, the gas outlet 43 of the reactor 40 is connected to the intake section 51 of the catalytic absorption tower 50, the intake section 51 of the catalytic absorption tower 50 is used to hold the absorption liquid, the absorption liquid is mixed with the second catalyst, and the catalytic absorption tower 50 The packing section 52 is equipped with adsorption packing, and the spray section 53 of the catalytic absorption tower 50 is provided with a spray pipe for spraying water or other liquids. The excavated soil is crushed by the crusher 10 and then enters the gas infrared heater 20. The infrared radiation emitted by the gas infrared heater 20 penetrates into the soil and heats the soil to blow off the organic matter adsorbed by the soil, generating a high temperature of 200°C-300°C VOC gas, the obtained soil can be directly landfilled after cooling down, or it can also be further processed; the high-temperature VOC gas enters the reactor, and the temperature drops to 150°C-250°C, and the VOC gas passes through its own heat. The surface of the catalyst 41 forms low-energy surface free radicals to generate vibrationally excited state products, that is, the VOC gas is oxidized under the action of the first catalyst 41 to remove part of the VOC gas; The intake section 51 of the absorption tower 50 enters the catalytic absorption tower, the second catalyst, and under the action of the second catalyst, the VOC gas generates organic acids with better water solubility, which are then absorbed by the absorption liquid to avoid environmental pollution by exhaust gas.

The particle size of the soil crushed by the crusher 10 is 1mm-10mm.

The gas-fired infrared heater 20 adopts a porous ceramic plate as a burner head, injects gas (such as LNG, etc.) and burns to generate infrared radiation to heat, dry and insulate the soil. In this embodiment, the infrared heating furnace 23 is installed below the conveyor belt 21 to heat the soil on the conveyor belt 21 through the conveyor belt 21 . In other embodiments, the infrared heating furnace 23 can be installed on the inner wall of the heating cavity 22 . The heating chamber 22 is semi-closed, and the conveyor belt 21 can enter and leave the heating chamber 22 from the bottom of the heating chamber 22 . The heating cavity 22 covers the soil, which can prevent heat loss and reduce fuel consumption.

A gas outlet 24 is opened on the top of the heating chamber 22 for extracting VOC gas.

The gas suction unit 30 includes a gas pipe 31 and a fan 32 connected to the gas pipe 31 , the gas pipe 31 is connected to the gas outlet 24 of the heating chamber 22 , and the outlet of the fan 32 is connected to the gas inlet 42 of the reactor 40 .

The reactor 40 can also communicate with the oxidant container 60 or the reductant container 70, so that the oxidant or the reductant can be added into the reactor 40 to accelerate the rate of catalytic oxidation or catalytic reduction.

Catalytic absorption tower 50 is equipped with spraying part, and this spraying part comprises water pipe 54, shower nozzle 55 and circulation pump 56, and one end of water pipe 54 stretches into the spray section 53 of catalytic absorption tower 50, and the other end stretches into catalytic absorption tower 50. The circulating pump 56 is installed in the position near the bottom of the water pipe 54, and the nozzle 55 is installed in the inlet section 51 where the water pipe 54 stretches into the catalytic absorption tower 50. The circulating pump 56 can pump the absorbing liquid to eject from the nozzle 55 to accelerate the dissolving of the gas.

Catalytic absorption tower 50 can communicate with oxidant container 60 or reductant container 70 or high-efficiency absorbent container 80, so that oxidant or reductant or high-efficiency absorbent is added in catalytic absorption tower 50, to accelerate the rate of catalytic oxidation or catalytic reduction or absorption . Specifically, when the oxidant container 60, the reductant container 70 or the high-efficiency absorbent container 80 are gas containers, they are connected to the water pipe 54, and the gas is directly passed into the water pipe 54, and is ejected into the catalytic absorption tower 50 along with the nozzle 55; For example, when the oxidant container 60 is an ozone generator, the oxidant container 60 is directly connected to the water pipe 54 . When the oxidant container 60 , the reductant container 70 or the high-efficiency absorbent container 80 is a liquid container, the oxidant container 60 , the reductant container 70 or the high-efficiency absorbent container 80 is connected to the intake section 51 of the catalytic absorption tower 50 . For example, when the oxidant container 60 is a hydrogen peroxide container, the hydrogen peroxide container is connected to the intake section 51 of the catalytic absorption tower 50 , and the hydrogen peroxide is directly added into the absorbent of the catalytic absorption tower 50 .

The reactor 40 and the catalytic absorption tower 50 can communicate with the oxidant container 60 or the reducing agent container 70 at the same time, or alternatively communicate with the oxidant container 60 or the reducing agent container 70 .

Further, the above-mentioned organic polluted soil purification device 100 also includes a soil excavation component 90 for excavating soil. The soil excavation component 90 is connected to the crusher 10 through the conveying device 102, and directly transports the excavated soil to the crusher 10 through the conveying device 102 for crushing.

The above-mentioned organic polluted soil purifying device 100 is used to realize the aforementioned method for purifying organic polluted soil.

Embodiment two

Please refer to Fig. 2, the difference between the present embodiment and the first embodiment is that a gas collecting hood 101 is arranged above the soil excavation part 90, and the gas collecting hood 101 communicates with a blasting part 103, and the blasting part 103 communicates with gas infrared heating The infrared heating furnace 23 of the device 20 is used to blow the VOC gas volatilized from the soil excavation point into the infrared heating furnace 23 for further combustion. On the one hand, it can save fuel, and on the other hand, it can also prevent the VOC gas from the excavation point from volatilizing into the air. pollute the environment.

The above-mentioned embodiments only express several implementation modes of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as limiting the patent scope of the present utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the scope of protection of the utility model patent should be based on the appended claims.

Claims (7)

1. a kind of organic polluted soil purification device characterized by comprising

Gas Infrared heater, the Gas Infrared heater include heating cavity, wear the heating cavity conveyer belt and The infrared heating furnace of infra-red radiation is provided for the soil on the conveyer belt；

The entrance of gas pumping part, the gas pumping part is connected to the top of the heating cavity；

Reactor, the reactor is interior to be entered filled with graininess or cellular first catalyst, the reactor with gas Mouth and gas vent, the gas access of the reactor are connected to the outlet of the gas pumping part；

Catalytic absorption tower, the catalytic absorption tower successively include air inlet section, packing section and spray section, the reactor from the bottom to top Gas vent be connected to the air inlet section of the catalytic absorption tower, the air inlet section of the catalytic absorption tower is for containing absorbing liquid, institute It states absorbing liquid and is mixed with the second catalyst, the packing section of the catalytic absorption tower is equipped with adsorption stuffing, the catalytic absorption tower Spray section is equipped with spray tube.

2. organic polluted soil purification device according to claim 1, which is characterized in that the organic polluted soil purification Device further includes that a soil excavates component, and a gas gathering mask, the gas gathering mask connection one is arranged in the top that the soil excavates component Air blast component, infrared heating furnace described in the air blast members, the VOC gas for soil to be excavated point volatilization are blown into described Infrared heating furnace.

3. organic polluted soil purification device according to claim 2, which is characterized in that the organic polluted soil purification Device further includes crusher, and the crusher connects the soil by conveying equipment and excavates component.

4. organic polluted soil purification device according to claim 1-3, which is characterized in that the reactor connects Logical oxidant vessel or container for reducing agent.

5. organic polluted soil purification device according to claim 1-3, which is characterized in that the catalytic absorption Tower is connected to oxidant vessel or container for reducing agent or efficient absorption agent container.

6. organic polluted soil purification device according to claim 5, which is characterized in that the oxidant vessel or reduction When agent container or efficient absorption agent container are gas container, the oxidant vessel or container for reducing agent or efficient absorption agent container It is connected to the air inlet section of the catalytic absorption tower.

7. organic polluted soil purification device according to claim 5, which is characterized in that the oxidant vessel or reduction When agent container or efficient absorption agent container are liquid container, the oxidant vessel or container for reducing agent or efficient absorption agent container It is connected to the spray tube.