KR-102959986-B1 - FREE-PHASE GROUNDWATER OIL EXTRACTION SYSTEM

Abstract

The present invention relates to a groundwater free-phase oil extraction system, comprising: a lipophilic/superhydrophobic floating part floating on the water surface; a suction part coupled to the floating part and floating on the water surface to continuously suck up free-phase oil located on the water surface in response to changes in the water surface; a coil-shaped first transfer line and a first pump connected to the suction part to transport the collected oil to the surface; a mooring part that temporarily receives the oil and re-separates the water and oil; and a second pump. The device system according to the present invention has a relatively simple configuration, enabling rapid installation. Consequently, the spread of the pollutant can be prevented in the early stages through a rapid initial response in the event of a pollutant spill. Furthermore, according to the present invention, the device can be implemented at a low cost, and only the pollutant can be selectively extracted from the pollutant and groundwater, thereby reducing the cost of surface wastewater treatment. Additionally, according to the present invention, only LNAPL, which is a pollutant located on the groundwater surface, can be selectively collected in response to groundwater with continuously changing water levels, thereby simplifying the wastewater treatment process and minimizing operating costs.

Inventors

• 이준명
• 노훈
• 김경수
• 추덕성

Assignees

• 바른종합기술 주식회사

Dates

Publication Date

20260508

Application Date

20221221

Claims (8)

1. A floating part (100) that is made of a superhydrophobic sponge material and has a density that allows it to float on the surface of groundwater and be positioned together on LNAPL; A first sensor (120) is provided to operate a first pump (200) when oil is detected, and a suction part (110) is coupled to the floating part (100) and floats on the water surface to suck up free-phase oil (O) located on the water surface in response to changes in the water surface; and A groundwater free-phase oil extraction system comprising: a first pump (200) positioned above and fixedly spaced apart from the floating part (100) and the suction part (110); and a first transfer line (L1) in the shape of a coil or spiral connected to the suction part (110) to transfer collected oil (O) to the ground. A groundwater free-phase extraction system comprising six suction modules combined with the floating section (100) and the suction section (110), arranged in a hexagonal shape, connected to each other at the center and connected to the first transfer line (L1) at the center.
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4. In Article 1, A mooring section (300) that receives oil (O) through a second transfer line (L2) connected to the first pump (200) and has a predetermined space formed inside so that the oil (O) can be stored; and A groundwater free-phase oil extraction system comprising: a second pump (400) provided at a position spaced apart by a predetermined height from the bottom surface of the mooring section (300) and transferring the oil (O) filling the predetermined space of the mooring section (300) to the ground through a third transfer line (L3).
5. In Article 4, The first pump (200) and the second pump (400) are electrically connected to external ground power (T2) and a conductive wire (L0), and A groundwater free-phase oil extraction system that prevents the inflow of foreign substances by providing a cap portion (500) through which only the third transfer line (L3) and the conductive line (L0) pass on the ground.
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Description

Free-Phase Groundwater Oil Extraction System The present invention relates to a groundwater free-phase oil extraction system. More specifically, it relates to a low-power, low-cost oil extraction system capable of selectively and continuously extracting only free-phase oil in response to changing water levels. Groundwater contamination caused by oil compounds, which are fuel hydrocarbons (TPH; Total Petroleum Hydrocarbon) classified as non-aqueous phase liquids (NAPL), mainly occurs from spills from underground oil storage tanks or spills from refineries, transfer lines, or oil transport. Oil compounds spilled into the soil move downward along the soil pores and, upon encountering a groundwater aquifer, float in a free phase above the groundwater. Their position can change vertically depending on the groundwater level, and they can also move horizontally along the upper part of the aquifer, spreading continuous soil contamination and extensive groundwater contamination, which can have a serious impact on the surrounding area and therefore requires rapid removal. According to the results of the Ministry of Environment's 2014 soil and groundwater environmental survey of areas of concern for contamination, petroleum compounds (TPH) exceeding contamination standards were detected in 31.6% of the 38 surveyed sites, including aging gas stations and industrial facilities near residential areas. In the case of industrial complexes, it was reported that the soil at 8 out of 16 surveyed companies (50%) was contaminated by petroleum. Groundwater contamination cases have been steadily increasing nationwide, with cleanup measures implemented in 2019 after groundwater levels in 24 locations near industrial complexes in Gwangju City exceeded contamination standards. In particular, detailed soil surveys conducted at sites where the second phase of the U.S. military base relocation project has been underway since 2019 have reported that large-scale soil and groundwater cleanup projects amounting to hundreds of billions of won are required. Meanwhile, Dual-Phase Extraction (DPE) and Two-Phase Extraction (TPE) processes are currently being researched and developed as methods to simultaneously extract oils and volatile chemicals distributed in high concentrations within the unsaturated soil layer and on the groundwater surface. Among these, DPE is a method that extracts contaminated soil vapor and contaminated groundwater individually by installing a contaminated groundwater extraction pipe separately from the soil vapor extraction pipe inside the extraction well and connecting them to different extraction pumps, whereas TPE is a method that extracts soil vapor and groundwater simultaneously through a single extraction pipe using a single high-vacuum pump. However, in the case of DPE, the equipment is complex and installation costs are high; operation is unstable due to frequent failures of submerged pumps; and problems arise regarding the treatment of excessive groundwater discharge during the restoration process because the submerged pumps are installed below the groundwater surface and selective oil extraction is impossible. Similarly, in the case of TPE, since selective oil extraction is also impossible, operating costs, including the cost of gas-liquid separation on the surface, are high due to the inflow of large amounts of groundwater. In addition, in environments with severe groundwater level fluctuations, groundwater reprocessing costs increase significantly when the groundwater level rises, and higher vacuum pressure is required when the groundwater level falls. Meanwhile, to overcome the disadvantages of DPE, a technology using a skimmer instead of an extraction pipe has recently been commercialized overseas. In the case of the skimmer, it moves up and down inside the extraction well according to changes in the groundwater level, allowing for more effective removal of LNAPL. Since it extracts mostly only LNAPL, it can be operated by installing only a waste oil storage tank without above-ground water treatment facilities. However, due to the limitations of the skimmer principle, there may be a problem where trace amounts of LNAPL remain in the groundwater. If the position of the skimmer is lowered within the groundwater to prevent this, it may have the disadvantage of continuously extracting even the non-contaminated groundwater below, thereby increasing the amount of waste oil to be treated. FIGS. 1 and 2 are schematic diagrams illustrating a groundwater free-phase oil extraction system according to an embodiment of the present invention. FIG. 3 is a diagram showing a groundwater free-phase oil extraction system according to an embodiment of the present invention collecting free-phase oil. FIG. 4 is a diagram showing a state in which a groundwater free-phase oil extraction system according to an embodiment of the present invention has stopped collection because it has not detected free-phase oil. FIGS. 5 and 6 are d