Sparging (chemistry)
In chemistry, sparging, also known as gas flushing in metallurgy, is a technique which involves bubbling a chemically inert gas, such as nitrogen, argon, or helium, through a liquid. This can be used to remove dissolved gases (e.g. oxygen) from the liquid. By Henry's law, the amount of dissolved gases in a liquid depend on the partial pressure of the gases exposed to the liquid. Sparging increases the gas-liquid interface.
Liquid chromatography[edit]
Solvents used in high-performance liquid chromatography (HPLC) are often sparged with helium.[1]
Engineering[edit]
In biochemical engineering, sparging can also be a method to remove low-boiling liquids from a solution. The low-boiling components tend to evaporate more rapidly, hence they may be removed from the bulk solution containing higher-boiling components. It is an alternative to distillation, and it does not require heat.
Environmental chemistry[edit]
This technique is also used in environmental chemistry to extract the volatile organic contaminants from subsoil water and soil.
Metallurgy[edit]
In metallurgy, this process is used to remove dissolved gases from the melt prior to the material being processed.[2][3] For example, before casting aluminium alloys, argon bubbles are injected into liquid aluminium using a rotary degasser. The resulting argon bubbles will rise to the surface, bringing with them a quantity of the dissolved hydrogen. This degassing treatment reduces the occurrence of hydrogen gas porosity.
References[edit]
- ^ M. W. Dong (2000). "Precision in HPLC. Mastering the art of HPLC". Today's Chemist at Work. American Chemical Society. 9 (8): 28–32.
- ^ Degarmo, E. Paul; Black, J T.; Kohser, Ronald A. (2003). Materials and Processes in Manufacturing (9th ed.). Wiley. p. 284. ISBN 0-471-65653-4.
- ^ Stefanescu, D. M. (1990). ASM handbook. Materials Park, OH: ASM International. ISBN 0-87170-021-2.
