Research On Prospecting For Oil Pollution Of Groundwater Based On Very Low Frequency

Petroleum products are one of the common sources of soil pollution caused by human activities,which cause major changes in soil microbial,chemical composition,structure and physical properties.The main purpose of this study was to assess groundwater contamination in the gas station area.During the operation of the gas station,oil leakage(corrosion damage of the oil storage container,etc.)and random discharge of oily sewage will cause groundwater pollution.The oil that penetrates into the ground may cause long-term unsustainable damage to the groundwater environment,and even damage people’s Healthy body.In the new era,the state advocates that “green mountains and green mountains are Jinshan Yinshan”,so it is extremely urgent to solve the problem of groundwater oil pollution.The very low frequency method(VLF)is an abbreviation for very low frequency electromagnetic method(VLF-EM),an electromagnetic method commonly used to measure the electromagnetic field distribution in space,surface and underground,to obtain electrical structural features based on local electrical differences,with propagation The characteristics are stable,the phase change is predictable,and the fundamental mode attenuation is small.In practical applications,it can use the large navigation platform that has been built as the source of the launching field for surveying.It does not need to bring its own source,avoiding the handling of heavy equipment such as power supply and cable necessary for other electromagnetic exploration technology in the field.The work has the advantages of simple and light equipment,high monitoring accuracy and low cost,so it is widely used in underground exploration in many countries and regions.A large number of relevant data prove that the VLF method has a good application prospect in the research of fault zones,bedrock fissure water and groundwater pollution monitoring in hydrology,prospecting and geological disasters.The research idea of this subject is to monitor the groundwater oil pollution status of gas stations by using the very low frequency method on the basis of software radio technology.When the very low frequency electromagnetic signal emitted by the high-power VLF communication navigation station encounters a good conductor in the ground,electromagnetic induction occurs,causing a certain change in its amplitude and phase.The monitoring system is based on the abnormal reaction of the electromagnetic wave propagation process,via computer software.The variation of amplitude and phase and the tangential electric field component and vertical magnetic field component of the very low frequency electromagnetic signal are analyzed.The collected data is uploaded to the calculation module in real time through the transmission module and the upper computer control module,and then the mathematical relationship is obtained.The groundwater apparent resistivity value of the leakage area is compared with the apparent resistivity value measured by the laboratory in the contaminated state by means of MATLAB.The dynamic penetration trajectory of groundwater pollution is estimated according to the graph,which proves the monitoring method can effectively outline the pollutant plume generated by underground tank leakage oil,which provides a basic basis for the subsequent treatment of groundwater oil pollution and further research on such problems.