In situ thermal treatment

Tse KKC, S-L Lo, JWH Wang (2001) Pilot study of in-situ thermal treatment for the remediation of pentachlorophenol-contaminated aquifers. Environ Sci Technol 35 4910-4915. 

In situ soil remediation with physical methods includes the in situ heating (in situ thermal treatment), ground-freezing, hydraulic fracturing, immobilization/stabilization, flushing, chemical detoxification, vapor extraction, steam extraction, biodegradation/bioremediation, electroosmosis/ electrokinetic processes, etc. 

FIGURE 16.14 In situ thermal treatment by steam injection. (Taken from U.S. EPA, A Citizen s Guide to In situ Thermal Treatment Methods, Technical Report EPA-542-F-01-012, U.S. EPA, Washington, DC, 2001.)... 

Information relevant to the application of in situ thermal treatment at sites contaminated with MTBE and other oxygenates is available in a U.S. EPA report.115... 

While no projects in the dataset were identified explicitly as using in situ thermal treatment, several projects discussed under other technologies involved these types of components. For example, one site in Texas discussed under bioremediation (Rural Area Disposal Area, Liberty, Texas) used a combination of technologies that included an in situ thermal treatment component. 

U.S. EPA, In Situ Thermal Treatment of Chlorinated Solvents Fundamentals and Field Applications, EPA 542-R-03-012, Office of Solid Waste and Emergency Response, United States Environmental Protection Agency, Washington, DC, July 2003. 

Can be used to enhance the performance of several in situ technologies, including bioremediation, in situ chemical oxidation, in situ thermal treatments, and in situ solidification. 

In situ thermal treatment — In situ thermal treatment allows pollutants to be treated without being excavated and transported. Thermal treatment requires a shorter clean-up time however, high costs are usually associated with the amount of energy and equipment required. For example, enhanced soil vapor extraction is usually an energy-intensive process. 

This chapter will present the principles governing thermal desorption and from this, the changes in chemical and biological reactions that occur during in situ thermal treatment. 

In the case of fermentation, the chlorinated aliphatic hydrocarbons act as TED, TEA, and carbon source. This may be occurring under in situ thermal treatment were yeastlike odors have been noted, but the degree to which this is occurring is uncertain. 

The organic substrates were resin layers formed by the spin coatingof PI-5878 (8juthick) onto Si wafers. The resin was heated to approximately 100°C on a hot plate for 20-30 minutes to remove excess solvent (i.e.,N-methylpyrroli-done) so as to form a rigid condensed-phase polyamic acid (PAA) layer. A 0.1% aqueous solution of JT-APS was then applied to the PAA film layer by use of a puddle-spin application method. These specimens were examined by XPS before and after in situ thermal treatment. The results were compared with those obtained for non-silane treated PAA films before and after curing. 

The preparation of BC hybrids with ZnO nanoparticles (BC/ZnO NPs) has been addressed in some studies by in situ thermal treatment of Zn aqueous solutions [268, 269, 270]. It was demonstrated that BC is a good template to prepare ZnO NPs nearly spherically in shape and with the average sizes of 20-50 nm [268] and 50-100 nm [270] (Figure 2.34). These BC/ZnO NPs can also serve as sources of pure ZnO NPs upon BC calcination [268]. 

More recently, low-energy ion scattering spectroscopy (LEISS) has been used to elucidate the surface coverage of the monolayer supported and bulk vanadium and molybdenum oxide-based catalysts under in situ thermal treatments [2]. In LEISS, a beam of ions (typically, He+) with a certain energy (0.1 to 10 keV) scatters elastically from the outermost layer of atoms since the ions that penetrates the solid are neutralized [1]. 

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