Underground water vertical circulation aeration repair system

Abstract

The invention discloses a vertical circulating aeration remediation system for underground water, and belongs to the field of soil and underground water remediation. The system is composed of overground aeration and extraction equipment and an underground vertical circulation aeration well, and a microbial agent is put by adopting an intelligent putting algorithm based on pollutant concentration monitoring and a microbial growth model. And the overground aeration and extraction equipment is used for pressing fresh air into an aeration head at the bottom of the vertical circulating aeration well through a gas pipeline by virtue of a ground air blower or an air compressor, and continuously extracting tail gas collected at the top of the vertical circulating aeration well by virtue of a ground vacuum pump. According to the invention, through one remediation well, the functions of underground water aeration, tail gas extraction, aeration zone polluted soil gas extraction, underground water monitoring, microbial agent addition, NAPL skimming, microbial degradation, vertical circulation remediation and the like are integrated, and integration of underground water aeration, tail gas extraction, NAPL skimming, microbial agent addition and vertical circulation remediation processes is realized; the repair cost is reduced, and the repair efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of soil and groundwater restoration, and in particular to a groundwater vertical circulation aeration restoration system. Background Art

[0002] Aeration remediation technology (AirSparging, AS) for groundwater pollution is an in-situ remediation technology for removing volatile organic compounds (VOCs) from soil and groundwater. It was first used in Germany in 1985 and is considered to be one of the most effective methods for removing volatile organic compounds from saturated soil and groundwater. It has attracted much attention and has good application prospects.

[0003] The in-situ aeration process injects a certain volume of compressed air into the aquifer to remove pollutants through stripping, volatilization, dissolution, adsorption-desorption and biodegradation. Under relatively permeable conditions, when volatile organic pollutants and aerobic biodegradable organic pollutants exist in the saturated zone at the same time, or when one of the pollutants exists, in-situ aeration can be used to remediate the polluted water. The pollutant removal mechanism during groundwater aeration includes three main aspects: first, stripping of soluble volatile organic pollutants; second, accelerating the volatilization of residual and adsorbed organic pollutants below the groundwater level and at the edge of the capillary; third, the injection of oxygen causes aerobic biodegradation of dissolved and adsorbed organic pollutants.

[0004] In order to realize the remediation process required by the technical plan, the remediation site often needs to build various types of remediation wells to meet the requirements of the remediation process for efficient treatment of pollutants of different depths and types. For example, NAPL extraction wells are set up to extract NAPL in the contaminated site; monitoring wells are set up for groundwater monitoring requirements; groundwater aeration wells and tail gas extraction wells are set up for groundwater aeration process; soil gas extraction wells in the aeration zone are set up to eliminate easily volatile soil pollution in the aeration zone; vertical circulation wells are set up to increase the influence radius of the remediation well and strengthen the pollutant removal effect in the strata around the remediation well; microbial agent addition wells are set up to increase the activity of site microorganisms and the microbial degradation effect of semi-volatile organic matter, etc. The more complex the pollution types in the site, the more types of remediation wells need to be set up to efficiently complete the remediation of the site, which increases the amount of on-site construction and subsequent operation and maintenance, and greatly increases the remediation period and cost.

[0005] In order to solve the above problems, the present invention proposes a groundwater vertical circulation aeration remediation system. The system realizes the integration of groundwater aeration, tail gas extraction, NAPL skimming, microbial agent addition and vertical circulation remediation process by drilling a well repair borehole. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects existing in the above-mentioned background technology, and proposes a groundwater vertical circulation aeration remediation system, which integrates groundwater aeration, tail gas extraction, gas extraction of contaminated soil in the vadose zone, groundwater monitoring, addition of high-efficiency microbial preparations, NAPL skimming, microbial degradation and vertical circulation remediation and other remediation functions through a remediation well, thereby realizing the integration of groundwater aeration, tail gas extraction, NAPL skimming, microbial agent addition and vertical circulation remediation process.

[0007] The present invention adopts the following technical solutions to solve the above technical problems:

[0008] A groundwater vertical circulation aeration remediation system, the system comprising:

[0009] Monitoring well cover (1); tail gas extraction pipe (2); monitoring well (3); compressed air pipeline (4), air compressor or blower presses fresh air into the aeration head through the compressed air pipeline; ground hardening layer (5); original soil layer (6); filler 1 (7), generally bentonite; filler 2 (8), generally quartz sand; tail gas extraction integrated filler section (9); tail gas extraction flower pipe (10); groundwater level line (11); fixed pipe (12); aeration head (13), which evenly distributes the pressed fresh air to the bottom of the repair well in the form of tiny bubbles; steam-water separator (14), which is used to separate water droplets extracted with the tail gas from the extraction pipeline; vacuum pump or induced draft fan (15), tail gas extraction power equipment; blower or air compressor (16), which presses fresh air into the underground aeration head through the compressed air pipeline;

[0010] The system integrates groundwater aeration, tail gas extraction, gas extraction of contaminated soil in the vadose zone, groundwater monitoring, addition of high-efficiency microbial agents, NAPL skimming, microbial degradation and vertical circulation remediation functions, realizing the integration of groundwater aeration, tail gas extraction, NAPL skimming, microbial agent addition and vertical circulation remediation processes; the NAPL is a non-aqueous phase liquid;

[0011] The system uses an intelligent delivery algorithm based on pollutant concentration monitoring and microbial growth model to deliver microbial agents into groundwater to enhance the remediation effect.

[0012] Furthermore, the tail gas extraction pipe extracts the volatile pollutants that have spilled onto the top of the repair well and around the aeration zone into the ground in a gaseous state through a vacuum pump or an induced draft fan.

[0013] Furthermore, the top of the monitoring well is sealed with a well cover to prevent ground air from entering the well pipe and causing a short circuit in the system gas. The upper part is a solid pipe section, and the lower part is a flower pipe section buried in quartz sand filler. In addition to monitoring groundwater, it can be used as a NAPL skimmer well when the pollution concentration of the land is high in the early stage.

[0014] Furthermore, the exhaust gas extraction integrated filler section is wrapped around the exhaust gas extraction flower tube, and the filler and the flower tube section are fixed into a whole through a metal material skeleton and a metal woven mesh wrapped around the outside of the filler, thereby enhancing the effect of the flower tube section in extracting exhaust gas and encapsulating soil gas.

[0015] Furthermore, the exhaust gas extraction flower pipe is located above the groundwater surface, and during operation, the groundwater level is required to be lower than the flower pipe to prevent the exhaust gas extraction effect from being reduced.

[0016] Furthermore, the fixed pipe connects the bottom aeration head with the exhaust gas extraction section composed of the exhaust gas extraction integrated filler section and the exhaust gas extraction flower pipe, and the top and bottom of the fixed pipe are sealed to avoid forming a gas short-circuit channel by conducting with the upper flower pipe and the bottom aeration head.

[0017] Furthermore, the algorithm accurately calculates the optimal time, dosage and frequency of microbial agent administration by real-time monitoring of the types and concentrations of pollutants in groundwater and combining analysis of the growth characteristics and degradation capabilities of administered microorganisms;

[0018] The specific process of the algorithm is as follows:

[0019] Step S1, initialization parameters: Assume the concentration of target pollutants in groundwater is C p , the microbial growth rate constant is μ max , the saturation constant is K s The initial concentration of microorganisms is X0, and the degradation rate constant of pollutants by microorganisms is k d , the active ingredient content of the agent is η;

[0020] Step S2: According to the microbial growth kinetics model and the pollutant degradation model, the microbial growth rate μ is calculated as: and the degradation rate of pollutants by microorganisms d for:

[0021] Step S3: Determine the dosage D and time interval Δt of the microbial agent: the pollutant concentration reduction target C set according to the remediation target target , calculate the amount of pollutants that need to be degraded within a certain period of time ΔC = C p -C target ; Then, according to the degradation rate of microorganisms r d and the volume V of groundwater in the remediation well, calculate the total amount of microorganisms required Finally, the dosage of the drug is calculated based on the active ingredient content η of the drug. The time interval Δt is dynamically adjusted according to the changes in the growth cycle and degradation rate of the microorganisms. By monitoring the changes in indicators such as the respiration rate or enzyme activity of the microorganisms and the concentration of pollutants, a feedback control algorithm is used to optimize the value of Δt to ensure that the microorganisms can work under the best growth and degradation conditions.

[0022] Compared with the prior art, the present invention adopts the above technical solution and has the following beneficial effects:

[0023] (1) The system of the present invention integrates the functions of groundwater aeration, tail gas extraction, gas extraction of contaminated soil in the vadose zone, groundwater monitoring, addition of high-efficiency microbial agents, NAPL skimming, microbial degradation and vertical circulation remediation, realizing the integration of groundwater aeration, tail gas extraction, NAPL skimming, addition of microbial agents and vertical circulation remediation processes, improving the remediation efficiency of soil and groundwater pollution, reducing the amount of on-site construction and subsequent operation and maintenance, and greatly reducing the remediation period and cost.

[0024] (2) The microbial agent delivery algorithm used in the system of the present invention is based on real-time monitoring and scientific calculation of multiple factors such as pollutant concentration and microbial characteristics. It can accurately customize the delivery strategy to adapt to the dynamic changes in the restoration environment, ensure that microorganisms can efficiently degrade pollutants, and significantly improve the restoration efficiency. Reasonable agent delivery helps maintain a stable microbial community, enhance the stability and reliability of the restoration system, and promote the restoration of ecological balance, which is in line with the concept of green restoration, reduces interference and negative impact on the environment, and promotes the restoration work to develop in a more environmentally friendly and sustainable direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall system of the present invention;

[0026] Figure 2 This is a flow chart of the intelligent delivery algorithm based on pollutant concentration monitoring and microbial growth model. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] A groundwater vertical circulation aeration remediation system, such as Figure 1 As shown, the system comprises:

[0029] Monitoring well cover (1); tail gas extraction pipe (2); monitoring well (3); compressed air pipeline (4); ground hardening layer (5); original soil layer (6); filler 1 (7), generally bentonite; filler 2 (8), generally quartz sand; tail gas extraction integrated filler section (9); tail gas extraction flower pipe (10); groundwater level line (11); fixed pipe (12); aeration head (13); steam-water separator (14); vacuum pump or induced draft fan (15), tail gas extraction power equipment; blower or air compressor (16);

[0030] The ground aeration and extraction equipment uses a ground blower or air compressor to press fresh air into the aeration head at the bottom of the vertical circulation aeration well through a gas pipeline, and continuously extracts the tail gas collected at the top of the vertical circulation aeration well through a ground vacuum pump.

[0031] After being pressurized by the ground aeration equipment, the fresh air enters the aeration head (13) through the compressed air pipeline (4). The fresh air is distributed by the aeration head and ejected from the aeration head in the form of tiny bubbles. The tiny bubbles rise under the action of buoyancy, and firstly discharge the volatile pollutants in the groundwater in the form of gas through the effects of stripping, volatilization, dissolution, adsorption-desorption, etc., so that the volatile gas rises with the air, and then is collected and discharged through the well pipe of the tail gas extraction integrated filling section (9) exposed to the groundwater surface at the top of the vertical circulation aeration well; at the same time, if there is pure phase NAPL around the repair well, the NAPL is enriched from the bottom to the top of the repair well due to the entrainment of the rising bubbles, and the NAPL can be skimmed off manually or by a skimmer pump through the monitoring well at the top, thereby realizing the enrichment and removal of NAPL in the formation. When the biodegradation capacity of the indigenous microorganisms in the remediation site is insufficient, microbial agents can be added to the groundwater aeration vertical circulation remediation well through the monitoring well (3). The system uses an intelligent delivery algorithm based on pollutant concentration monitoring and microbial growth model to deliver microbial agents to the groundwater to enhance the remediation effect; the specific process of the algorithm is as follows:

[0032] Step S1, initialization parameters: Assume the concentration of target pollutants in groundwater is C p , the microbial growth rate constant is μ max , the saturation constant is K s The initial concentration of microorganisms is X0, and the degradation rate constant of pollutants by microorganisms is k d , the active ingredient content of the agent is η;

[0033] Step S2: According to the microbial growth kinetics model and the pollutant degradation model, the microbial growth rate μ is calculated as: and the degradation rate of pollutants by microorganisms d for:

[0034] Step S3: Determine the dosage D and time interval Δt of the microbial agent: the pollutant concentration reduction target C set according to the remediation target target , calculate the amount of pollutants that need to be degraded within a certain period of time ΔC = C p -C target ; Then, according to the degradation rate of microorganisms r d and the volume V of groundwater in the remediation well, calculate the total amount of microorganisms required Finally, the dosage of the drug is calculated based on the active ingredient content η of the drug. The time interval Δt is dynamically adjusted according to the changes in the growth cycle and degradation rate of the microorganisms. By monitoring the changes in indicators such as the respiration rate or enzyme activity of the microorganisms and the concentration of pollutants, a feedback control algorithm is used to optimize the value of Δt to ensure that the microorganisms can work under the best growth and degradation conditions.

[0035] In addition, due to the large amount of fresh air being pressed in, a large amount of oxygen in the air is dissolved into the water body, increasing the oxygen content of the water body, providing an oxygen-rich environment for underwater microorganisms to decompose non-volatile organic matter, and improving the bioremediation effect of organic matter; finally, due to the rise of bubbles at the bottom, the groundwater in the remediation well will form an upward movement, and the groundwater around the aeration head at the bottom of the remediation well will gather to the bottom of the remediation well. Due to the negative pressure extraction and the continuous rise of bubbles at the aeration head at the top of the remediation well, the groundwater level at the top of the remediation well rises, and the groundwater at the top tends to diffuse to the surroundings, thus forming a circulating flow field centered on the remediation well, allowing the groundwater to continuously leach the pollution sources around the remediation well and migrate the pollution to the remediation well, and then through the aeration, flotation, biological decomposition, NAPL skimming, tail gas extraction and other functions of the remediation well, the vertical circulation aeration remediation well and the surrounding groundwater and soil pollution are continuously reduced.

[0036] The present invention realizes groundwater aeration, tail gas extraction, NAPL skimming, microbial agent addition + vertical circulation remediation through a remediation well, integrating multiple remediation processes in one, saving construction investment costs, and greatly improving the remediation efficiency of soil and groundwater pollution.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A groundwater vertical circulation aeration remediation system, characterized in that: The system comprises: Monitoring well cover (1); tail gas extraction pipe (2); monitoring well (3); compressed air pipeline (4), air compressor or blower presses fresh air into the aeration head through the compressed air pipeline; ground hardening layer (5); original soil layer (6); filler 1 (7), generally bentonite; filler 2 (8), generally quartz sand; tail gas extraction integrated filler section (9); tail gas extraction flower pipe (10); groundwater level line (11); fixed pipe (12); aeration head (13), which evenly distributes the pressed fresh air to the bottom of the repair well in the form of tiny bubbles; steam-water separator (14), which is used to separate water droplets extracted with the tail gas from the extraction pipeline; vacuum pump or induced draft fan (15), tail gas extraction power equipment; blower or air compressor (16), which presses fresh air into the underground aeration head through the compressed air pipeline; The system integrates groundwater aeration, tail gas extraction, gas extraction of contaminated soil in the vadose zone, groundwater monitoring, addition of high-efficiency microbial agents, NAPL skimming, microbial degradation and vertical circulation remediation functions, realizing the integration of groundwater aeration, tail gas extraction, NAPL skimming, microbial agent addition and vertical circulation remediation processes; the NAPL is a non-aqueous phase liquid; The system uses an intelligent delivery algorithm based on pollutant concentration monitoring and microbial growth model to deliver microbial agents into groundwater to enhance the remediation effect.

2. A groundwater vertical circulation aeration remediation system according to claim 1, characterized in that: The tail gas extraction pipe extracts the volatile pollutants that have spilled over the top of the repair well and around the aeration zone into the ground in a gaseous state through a vacuum pump or an induced draft fan.

3. A groundwater vertical circulation aeration remediation system according to claim 1, characterized in that: The top of the monitoring well is sealed with a well cover to prevent ground air from entering the well pipe and causing a short circuit in the system gas. The upper part is a solid pipe section, and the lower part is a flower pipe section buried in quartz sand filler. In addition to monitoring groundwater, it can be used as a NAPL skimmer well when the pollution concentration of the land is high in the early stage.

4. A groundwater vertical circulation aeration remediation system according to claim 1, characterized in that: The exhaust gas extraction integrated filler section is wrapped around the exhaust gas extraction flower tube, and the filler and the flower tube section are fixed into a whole through a metal material skeleton and a metal woven mesh wrapped around the outside of the filler, thereby enhancing the effect of the flower tube section in extracting exhaust gas and encapsulating soil gas.

5. A groundwater vertical circulation aeration remediation system according to claim 1, characterized in that: The tail gas extraction flower pipe is located above the groundwater surface. During operation, the groundwater level is required to be lower than the flower pipe to prevent the tail gas extraction effect from being reduced.

6. A groundwater vertical circulation aeration remediation system according to claim 1, characterized in that: The fixed pipe connects the bottom aeration head with the tail gas extraction section composed of the tail gas extraction integrated filler section and the tail gas extraction flower pipe, and the top and bottom of the fixed pipe are sealed to avoid forming a gas short-circuit channel through conduction with the upper flower pipe and the bottom aeration head.

7. A groundwater vertical circulation aeration remediation system according to claim 1, characterized in that: The algorithm accurately calculates the optimal time, dosage and frequency of microbial agent administration by real-time monitoring of the types and concentrations of pollutants in groundwater and combining analysis of the growth characteristics and degradation capabilities of the administered microorganisms; The specific process of the algorithm is as follows: Step S71, initialization parameters: assuming the concentration of the target pollutant in groundwater is C p , the microbial growth rate constant is μ max , the saturation constant is K s The initial concentration of microorganisms is X0, and the degradation rate constant of pollutants by microorganisms is k d , the active ingredient content of the agent is η; Step S72: According to the microbial growth kinetics model and the pollutant degradation model, the microbial growth rate μ is calculated as: and the degradation rate of pollutants by microorganisms d for: Step S73, determine the dosage D and time interval Δt of the microbial agent: the pollutant concentration reduction target C set according to the remediation target target , calculate the amount of pollutants that need to be degraded within a certain period of time ΔC = C p -C target ; Then, according to the degradation rate of microorganisms r d and the volume V of groundwater in the remediation well, calculate the total amount of microorganisms required Finally, the dosage of the drug is calculated based on the active ingredient content η of the drug. The time interval Δt is dynamically adjusted according to the changes in the growth cycle and degradation rate of the microorganisms. By monitoring the changes in indicators such as the respiration rate or enzyme activity of the microorganisms and the concentration of pollutants, a feedback control algorithm is used to optimize the value of Δt to ensure that the microorganisms can work under the best growth and degradation conditions.

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