Stable isotopic analysis of water in plant, soil, and hydrological studies often requires the extraction of water from plant or soil samples. Cryogenic vacuum extraction is one of the most widely used and accurate extraction methods to obtain such water samples. Here, we present a new design of a cryogenic vacuum extraction system with 18 extraction slots and an innovative mechanism to aerate t...

An intermediate-scale flow cell experiment was conducted to study the removal of a DNAPL mixture from a layered porous medium through soil vapor extraction (SVE) with moist and dry air. A dual-energy gamma radiation system was used at various times to non-intrusively determine fluid saturations. The mixture, which contained the volatile organic carbon tetrachloride, mimics the DNAPL disposed at...

Many non-aqueous phase liquids (NAPLs) are expected to spread at the air-water interface, particularly under non-equilibrium conditions. In the vadose zone, this spreading should increase the surface area for mass transfer and the efficiency of volatile NAPL recovery by soil vapor extraction (SVE). Observations of spreading on water wet surfaces led to a conceptual model of oil spreading vertic...

1.0 Introduction .............................................. 1 2.0 Background on Issue Paper ....................... 2 3.0 In Situ Treatment Technologies ............... 2 3.1 Physical/Chemical Treatment Technologies ...................................... 2 3.1.1 Soil Vapor Extraction ............... 2 3.1.2 Solidification/Stabilization ........ 6 3.1.3 Chemical Oxidation ......................

So far, no research has been focused on the determination of organomercuries in sewage sludge. Here, an ultrasonic extraction method for the rapid determination of methylmercury (MeHg) and ethylmercury (EtHg) in sewage sludge after ultrasound-assisted extraction is proposed. Using TMA (tetramethylammonium hydroxide) as the extractant with 3.0 g copper powder, ultrasonic extraction for 30 min at...

Vapor intrusion from affected soils and groundwater into overlying structures has been identified as a potential mechanism for human exposure to volatile organic chemicals (VOCs), including petroleum hydrocarbons. However, in many cases, background concentrations of organic vapors in indoor air, associated with household products, vehicles, or ambient air, can lead to incorrect conclusions rega...

This chapter focuses on three widely used techniques for extraction of semivolatile organics from liquids: liquid–liquid extraction (LLE), solid-phase extraction (SPE), and solid-phase microextraction (SPME). Other techniques may be useful in selected circumstances, but these three techniques have become the extraction methods of choice for research and commercial analytical laboratories. A fou...