American Society of Civil Engineers


Low-Temperature Oxygen Trap for Maintaining Strict Anoxic Conditions


by Byong-Hun Jeon, (Research Associate, Dept. of Civ. & Envir. Engrg., Pennsylvania State Univ., 212 Sackett Bldg., University Park, PA 16802-1408.; formerly, Ph.D. candidate, Depet. of Civ. and Envir. Engrg., Pennsylvania State Univ., presently, Pacific Northwest Natl. Lab., P.O. Box 999, MS K8-96, Richland, WA 99352. E-mail: bxj114@bama.ua.edu), Brian A. Dempsey, M.ASCE, (Prof., Dept. of Civ. & Envir. Engrg., Pennsylvania State Univ., 212 Sackett Bldg., University Park, PA 16802-1408), Richard A. Royer, (Res. Assoc., Dept. of Civ. & Envir. Engrg., Pennsylvania State Univ., 212 Sackett Bldg., University Park, PA 16802-1408), and William D. Burgos, M.ASCE, (Assoc. Prof., Dept. of Civ. & Envir. Engrg., Pennsylvania State Univ., 212 Sackett Bldg., University Park, PA 16802-1408)

Journal of Environmental Engineering, Vol. 130, No. 11, November 2004, pp. 1407-1410, (doi:  http://dx.doi.org/10.1061/(ASCE)0733-9372(2004)130:11(1407))

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Document type: Technical Note
Abstract: A low-temperature O2 trap was designed in order to achieve strict anoxic conditions. The work was motivated by observation of slow oxidation of Fe(II) in an anaerobic chamber, leading to an estimated 3.8×10-7 atm O2 (well below the O2 monitor detection limit) despite recirculation of the N2:H2 atmosphere across a Pd catalyst. Very low O2 activity inside an “anaerobic” chamber can result in erroneous conclusions regarding oxidation-reduction reactivities in anoxic environments. The O2 trap consisted of two sequential barrier suspensions with 93.2 mM Fe(III) as ferric hydroxide, 0.90 mM FeCl2, and pH 8.1. The partial pressure of O2 was estimated to be less than 7.5×10-9 atm O2 when reactors were attached to the traps, based on no observed oxidation of Fe(II).


ASCE Subject Headings:
Abatement and removal
Anaerobic treatment
Oxidation
Oxygen
Temperature effects