Appeal No. 1997-2755
Application 08/311,426
groundwater examined. The method taught by Fathepure involves the complete
degradation of polychlorinated hydrocarbons by a two-stage biofilm reactor. In this
reactor, organic halides such as hexachlorobenzene (HCB), tetrachloroethylene (PCE),
and chloroform (CF) are first reductively dechlorinated in an anaerobic portion using a
carbon source such as glucose. These organic halides, however, are only dechlorinated to
the levels of tri- and dichlorinated products in the anaerobic portion of the reactor. See
Table I on page 3420 of Fathepure. Complete dechlorination of these organic halides only
occurs in the second aerobic stage of the reactor where an oxygen source is added.
Therefore, Fathepure fails to teach of the complete reductive dehalogenation of the
organic halides. Rather, the method of Fathepure requires a second, aerobic step to
achieve complete dehalogenation.
Fathepure also fails to describe an in situ method of organic halide dehalogenation
as part of that work . To supply this missing teaching, the examiner refers to a reference
7a (Dooley-Danna) disclosed on page 3422 of Fathepure. However, the examiner
Dooley-Danna describe the sequential anaerobic/aerobic biodegradation of chlorinated
ethenes in an aquifer simulator. In situ biodegradation of tetrachloroethylene (PCE) and
trichloroethylene (TCE) is performed by adding nutrients to groundwater that stimulate the
activity of naturally occurring bacteria. In the first anaerobic stage, PCE and TCE are
degraded to dichloroethylene (DCE). Oxygen is then introduced in the aerobic stage to
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