Dipartimento di Geoscienze, Università di Padova, Padova, Italy,
Environ Sci Pollut Res Int. 2014;21(15):8914-31. doi: 10.1007/s11356-014-2494-7. Epub 2014 Mar 13.
The characterization of contaminated sites can benefit from the supplementation of direct investigations with a set of less invasive and more extensive measurements. A combination of geophysical methods and direct push techniques for contaminated land characterization has been proposed within the EU FP7 project ModelPROBE and the affiliated project SoilCAM. In this paper, we present results of the investigations conducted at the Trecate field site (NW Italy), which was affected in 1994 by crude oil contamination. The less invasive investigations include ground-penetrating radar (GPR), electrical resistivity tomography (ERT), and electromagnetic induction (EMI) surveys, together with direct push sampling and soil electrical conductivity (EC) logs. Many of the geophysical measurements were conducted in time-lapse mode in order to separate static and dynamic signals, the latter being linked to strong seasonal changes in water table elevations. The main challenge was to extract significant geophysical signals linked to contamination from the mix of geological and hydrological signals present at the site. The most significant aspects of this characterization are: (a) the geometrical link between the distribution of contamination and the site's heterogeneity, with particular regard to the presence of less permeable layers, as evidenced by the extensive surface geophysical measurements; and (b) the link between contamination and specific geophysical signals, particularly evident from cross-hole measurements. The extensive work conducted at the Trecate site shows how a combination of direct (e.g., chemical) and indirect (e.g., geophysical) investigations can lead to a comprehensive and solid understanding of a contaminated site's mechanisms.
受污染场地的特征描述可受益于直接调查与一系列非侵入性和更广泛的测量相结合。在欧盟 FP7 项目 ModelPROBE 及其附属项目 SoilCAM 中，提出了用于污染土地特征描述的地球物理方法和直接推技术的组合。在本文中，我们介绍了在特雷卡泰（意大利西北部）现场进行的调查结果，该场地于 1994 年受到原油污染。非侵入性调查包括探地雷达（GPR）、电阻率层析成像（ERT）和电磁感应（EMI）测量，以及直接推采样和土壤电导率（EC）测井。许多地球物理测量都是在时移模式下进行的，以便分离静态和动态信号，后者与地下水位强烈的季节性变化有关。主要的挑战是从现场存在的地质和水文信号中提取与污染相关的重要地球物理信号。该特征描述的最重要方面是：(a) 污染分布与场地异质性之间的几何关系，特别考虑到存在渗透性较差的地层，这可以从广泛的地面地球物理测量中得到证明；(b) 污染与特定地球物理信号之间的关系，这从跨孔测量中可以明显看出。在特雷卡泰现场进行的广泛工作表明，直接（例如化学）和间接（例如地球物理）调查的组合如何导致对污染场地机制的全面而可靠的理解。
