Double-pump multiphase extraction device and control method thereof applied to soil groundwater remediation

Abstract

The invention discloses a double-pump multiphase extraction device and a control method thereof applied to soil groundwater remediation. The extraction device comprises an extraction well system, a gas-phase extraction and treatment system and a liquid-phase extraction and pretreatment system; the gas-phase extraction and treatment system comprises a gas filter, a vacuum pump, a cooling water tank and activated carbon adsorption tanks; and the liquid-phase extraction and pretreatment system comprises an oil-water separator, an air compressor, a main control board, an air bag pump and a liquid level probe, wherein the liquid level probe is connected to the main control board through a wire, the air bag pump communicates with the air compressor through a compressed air pipe and communicates with the oil-water separator through a water outlet pipe, a compressed air electromagnetic valve is arranged on the compressed air pipe and is connected to the main control board, and the oil-water separator is connected to a wastewater treatment system through a water outlet valve and communicates with a hazardous waste recycling device through an emptying valve. The double-pump multiphase extraction device and the control method thereof applied to the soil groundwater remediation have the advantages that the position of extracted groundwater can be adjusted in real time, and the requirement for flexibly adjusting the parameters of the remediation work can be met.

Description

technical field [0001] The invention relates to the field of soil and groundwater restoration, in particular to a dual-pump multiphase extraction device and a control method for soil and groundwater restoration. Background technique [0002] Multiphase extraction is an in-situ remediation technology, the main feature is that soil gas, groundwater and non-aqueous phase fluid (Non-Aqueous Phase Liquid, NAPL) are simultaneously extracted under vacuum-enhanced conditions, and then discharged after being treated by ground treatment facilities Or take the next step to remediate the soil and groundwater in the contaminated area. Non-aqueous phase fluid is also called free phase in the field of soil and groundwater remediation. The main advantage of multiphase extraction technology is that this technology is a combination of multiple restoration technologies, including pumping treatment, soil gas extraction, biological ventilation, free phase recovery, etc., and can simultaneously ...

AI Technical Summary

Problems solved by technology

The single-pump multiphase extraction system has the following three obvious limitations: 1) The single-pump multiphase extraction system realizes the extraction of groundwater through negative pressure. For areas with deep groundwater, a large vacuum pump is required to provide sufficient negative pressure. , thus putting forward very high requirements on the pressure resistance and airtightness of the system and pipelines, and then the whole system has large investment and high energy consumption, which is generally not feasible for engineering; 2) single-pump extraction systems generally It is impossible to adjust the extraction position in real time according to the needs of the restoration project; 3) The groundwater and NAPL are emulsified during the simultaneous extraction process, which makes the subsequent oil-water separation effect worse. Then the subsequent wastewater treatment load becomes larger

Although the single-pump multiphase extraction device can extract as much NAPL as possible by adjusting the position of the extraction dropper in the extraction well and reduce the amount of subsequent wastewater treatment, it is difficult to control the flow rate of groundwater extracted by the vacuum pump, and the extraction process is difficult. Severe disturbance will inevitably cause mixing between groundwater and NAPL and emulsification

[0004] The double-pump multi-phase extraction system can effectively overcome the disadvantages of the above-mentioned single-pump system, but due to its relatively complex system design, relatively high installation, operation and maintenance costs, there are no related patents and mature complete sets of equipment in China

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