Chemical plume

Groundwater pollution problems, however, are modeled using a two dimensional analysis. A typical aquifer has area dimensions that are much hirger than the vertical dimension. Therefore, chemictils dissolved in the groundwater aclticvc ertical uniformity a short distance from the source and the chemical plume will move in the lateral and longitudinal directions. 

T. Kikas, H. Ishida and J. Janata, Chemical plume tracking. 3. Ascorbic acid A biologically relevant marker, Anal. Chem., 74 (2002) 3605-3610. 

Short RT, Toler SK, Kibelka GPG, Roa DTR, Bell RJ, Byrne RH (2006) Detection and quantification of chemical plumes using a portable underwater membrane introduction mass spectrometer. Trends Anal Chem 25 637-646... 

This should provide direction as to how operations staff, emergency responders, and the public should respond to a potential toxic release (e.g., chemical plumes released), including facility evacuation, personnel accountability, proper personal protective equipment (PPE) as dictated by the Risk Management Program and Process Safety Management Plan, and whether the nearby public should be in-place sheltered or evacuated. 

Dasi, L. P. Statistical Characteristics of Turbulent Chemical Plumes. Master s Thesis, Georgia Institute of Technology, Atlanta, Georgia, July 2000. 

Figure 5.1 shows a photograph of a chemical plume in a turbulent water flow. The dye in this example has been released from a small orifice upstream of... 

Several laboratory studies have contributed to our understanding of turbulent chemical plumes and the effects of various flow configurations. Fackrell and Robins [25] released an isokinetic neutrally buoyant plume in a wind tunnel at elevated and bed-level locations. Bara et al. [26], Yee et al. [27], Crimaldi and Koseff [28], and Crimaldi et al. [29] studied plumes released in water channels from bed-level and elevated positions. Airborne plumes in atmospheric boundary layers also have been studied in the field by Murlis and Jones [30], Jones [31], Murlis [32], Hanna and Insley [33], Mylne [34, 35], and Yee et al. [36, 37], In addition, aqueous plumes in coastal environments have been studied by Stacey et al. [38] and Fong and Stacey [39], The combined information of these and other studies reveals that the plume structure is influenced by several factors including the bulk velocity, fluid environment, release conditions, bed conditions, flow meander, and surface waves. 

Based on the discussed example parameters that influence the turbulent mixing process, it is clear that plume structure can be described in general terms, but the specific characteristics are likely to be case dependent. Nevertheless, certain characteristics, such as those employed by the odor-gated rheotaxis with bilateral comparison strategy, may be similar enough to allow animals and engineered systems to track chemical plumes for a wide range of flow conditions. 

In June 2003, the SeaPup sensor was tested at a site off the Atlantic coast. As was discussed in Section 6.4.3, the SeaPup sensor showed almost an order of magnitude improvement in sensitivity over the SeaDog due to design enhancements incorporated into the system. In addition, the SeaPup responds much more rapidly to TNT than the SeaDog, which is an important advantage for mapping chemical plumes in the marine environment. 

Georgia Institute of Technology School of Civil/Environmental Engineering 790 Atlantic Drive Atlanta, GA, 30332 Ph 404.894.6704 (Dr. Donald Webster) www.ce.gatech. edu Environmental fluid mechanics and turbulence of chemical plumes. 

Chapter 5, The Structure of Chemical Plumes, continues the thrust of the preceding chapter by describing in detail the way small concentrations of chemicals are transported through water or air. 

Fig. 10.14 Chemical plume of red dye spreading in turbulent stream. Highlighted sensors from the array are positioned downstream from the nozzle at distances LI and L2. They are selected for correlation analysis...

Fast response is possible with swelling-based sensing mechanisms. For example, the mapping of a chemical plume caused by a release into the air could employ such a sensor positioned on an unmanned aerial vehicle (UAV). With this vehicle traveling at 40 miles/h, subsecond response times would be required to locate and map out the released analyte. An example of this is shown in Fig. 16, which describes a thin film of poly(2,2-bistrifluoromethyl-4,5-difluoro-l,3-dioxole-co-tetrafluoroethylene), Teflon AF placed on an interferometer which in turn was placed in the nose cone of an UAV, which was positioned in a wind tunnel with the wind moving at 40 mph. Small amounts of toluene vapor were introduced into the air stream to get an idea of whether the sensor would work in such an application. The sensor responded quickly, established equilibrium in seconds, and reversibly returned to baseline after the material passed. 

Groundwater treatment wall purifies chemical plume... 

NONLINEAR CHEMICAL PLUME DETECTION USING KERNEL-BASED MATCHED SUBSPACE DETECTORS... 

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