Application Research Of Ground Penetrating Radar And Borehole Sampling Analysis In Investigation Of A Chromium Contaminated Site

Sites contaminated of heavy metals are environmental problems left over by heavy industrial production.Investigation of sites contaminated of heavy metals is an important part of the implementation of restoration projects.With the gradual maturity of Geophysical Exploration Technology,Ground Penetrating Radar(GPR)detection technology is one of the important means of environmental geophysical prospecting,which has been widely used in polluted site investigation projects.The application effect is good,and it has become an accurate,fast,convenient and reliable technical method in the investigation of polluted sites at this stage.In this paper,the combination of Ground Penetrating Radar(GPR)and borehole sampling is used to identify the chromium pollution status of chromium-contaminated sites and clarify the groundwater pollution leakage area.The research area is an electroplating plant.The main electroplating processes are chromium plating and galvanizing,which will produce a large amount of chromium-containing electroplating wastewater.The thickness of the Quaternary layer is 4~40m in the study area,and the thickness of the soil layer at the bottom of the main electroplating workshop is 4~5m.In this paper,through the analysis of site geology and hydrogeological conditions,comprehensive application research using(GPR)and sampling analysis,the following conclusions are drawn:(1)The soil areas contaminated by chromium include electroplating workshops and their surroundings,deplating workshops,galvanizing workshops and the north side,chromium plating workshops and surroundings,wastewater treatment workshops and wastewate storage ponds,sewage drainage ditches and flood drainage ditches in the electroplating plants in the study area;(2)The results of on-site ground penetrating radar detection and sampling indicate that the areas where the soil chromium content exceeds the standard(greater than 400 mg/kg)include electroplating workshops,deplating workshops,galvanizing workshops to the north,and chromium plating workshops.In the southwest corner of the side and chrome plating workshop,the total area of contaminated soil with total chromium content higher than 400mg/kg is 301.8m~2.(3)The detection rate of hexavalent chromium on the north side of the galvanizing workshop is low.The existence form of chromium mainly exists in a stable state,and the unstable state and the less harmful to the environment account for less.This can be used as a reference for soil remediation in this area.(4)The numerical simulation software Visual MODFLOW was used to simulate the infiltration process of chromium-containing electroplating wastewater in the chromium plating workshop,and the traceability of groundwater pollutants was simulated.The simulation results are close to the measured results.