University of Mons, Faculty of Engineering, Fundamental and Applied Geology Department, 20 Place du Parc, 7000 Mons, Belgium.
J Contam Hydrol. 2012 Aug;136-137:25-42. doi: 10.1016/j.jconhyd.2012.05.003. Epub 2012 May 15.
Without a good estimation of samples representativeness, the delineation of the contaminated plume extent and the evaluation of volumes of hydrocarbon-impacted soils may remain difficult. To contribute to this question, a time domain induced polarization (IP) field experiment was conducted on an industrial waste land. Boreholes were drilled to specify the local geological context. Cross-hole seismic tomographies were performed to extend borehole logs and to draw an interpreted geological cross-section. Soil samples taken during drillings were analysed in laboratory. A preliminary survey was conducted to locate the IP profile. The polarization signatures linked to the presence of clayey sediments were filtered out from the data set. Chargeability and resistivity depth soundings were computed and compared to mean concentrations of total organic products to overcome the data support issue between the geophysical models and the spot samples of soils. A logarithmic relation between chargeabilities and smoothed hydrocarbon concentrations in soils was found. Taking into account contaminant's concentration thresholds defined in local codes and regulations allows defining chargeability classes to delineate hotspots on this site. This showed that IP tomography can be an accurate screening methodology. A statistical methodology is proposed to assess the efficiency of the investigation strategy.
如果不能很好地估计样本的代表性，那么污染羽范围的划定和受烃类污染土壤体积的评估可能仍然很困难。为了解决这个问题，在一个工业废弃地上进行了时间域激发极化（IP）现场实验。钻孔以确定当地的地质情况。进行了井间地震层析成像，以扩展钻孔记录并绘制解释性地质横剖面图。在实验室中对钻探过程中取出的土壤样本进行了分析。进行了初步调查以定位 IP 剖面。从数据集过滤掉与粘性沉积物存在相关的极化特征。计算了电导率和电阻率深度探测，并与总有机产物的平均浓度进行了比较，以克服地球物理模型和土壤现场样本之间的数据支持问题。发现电导率与土壤中平滑烃浓度之间存在对数关系。考虑到当地法规和规定中定义的污染物浓度阈值，可以定义电导率类别来划定该地点的热点。这表明 IP 层析成像可以是一种准确的筛选方法。提出了一种统计方法来评估调查策略的效率。
