Rapid In-Field Approaches for Delineating VOC in Both Soil Vapour and Groundwater for Vapour Intrusion Assessment

Abstract

Traditional contaminated site characterisation approaches are time-consuming, labour-intensive, and demand a high level of expertise. This case study provides a rapid field-based solution to investigating a VOC contaminated site and its vapour incursion by combining soil vapour and groundwater survey. To fully assess the volatile organic compound (VOC) distribution in a contaminated site, a number of self-developed soil vapour sampling probes (SVSPs) were placed vertically at different locations in a grid with different depths. Hence, 3D subsurface contour maps for VOC concentrations in soil vapour can be obtained and used to help identify hot spots and the migration patterns of VOCs. This SVSP is “easy-to-install” in the field and a cost-effective solution for rapid assessment of soil vapour samples. The SVSPs can be installed both vertically and horizontally. If there is a requirement to take soil vapour samples beneath an existing building from a potential contamination source zone, SVSPs can be horizontally installed beneath the building without compromising its structural integrity. In addition, to ascertain the correct groundwater channels that are likely to carry contaminants from a potential source zone, an electrical resistivity tomography technique was employed to provide the preliminary information for groundwater delineation in a complex groundwater channel network.

The Key Factors for the Fate and Transport of Petroleum Hydrocarbons in Soil With Related in/ex Situ Measurement Methods: An Overview

“…A field-portable Torion-T9 GC-MS, which provides analytical information that is definitive for many types of samples containing the organic analyte(s) using solidphase microextraction (SPME) and Needle Trap as the default sampling method. As demonstrated in our previous study (Wang et al, 2021a;Wang et al, 2021b), Torion-T9 portable GC-MS can provide results within minutes and is suitable for on-site analysis.…”

Review and Perspective: Gas Separation and Discrimination Technologies for Current Gas Sensors in Environmental Applications

“…For subppb or ppt level detection, preconcentration technology, such as solid-state microextraction fiber, can be applied for sampling and preconcentration. The preconcentration technologies have been widely applied to μGC-MS. , …”

“…For subppb or ppt level detection, preconcentration technology, such as solid-state microextraction fiber, can be applied for sampling and preconcentration. The preconcentration technologies have been widely applied to μGC-MS. 6,7 Advanced MOS and eNose. According to the literature, 62,65 MO sensor arrays and data analysis algorithms, such as eNose, can aid in detecting multiple gases simultaneously.…”

“…Recently, several studies have documented the use of portable GC-MS for characterizing and delineating contaminated sites. 6,7 Although they are accurate and precise, the expense of acquisition, the difficulty of operation, and the time required for the analysis all prohibit the wider use of these systems, especially for network monitoring. VI and the VOC results obtained from the field can differ by a huge margin due to spatial and temporal variations.…”

“…In-field analysis significantly reduces labor and commercial laboratory costs, while also speeding up the time it takes to obtain results. Recently, several studies have documented the use of portable GC-MS for characterizing and delineating contaminated sites. , Although they are accurate and precise, the expense of acquisition, the difficulty of operation, and the time required for the analysis all prohibit the wider use of these systems, especially for network monitoring.…”