Analysis of TCE decay.

First-order decay curves at SG-106

Here we focus on the project period between 12/4/2019 - 12/14/2019.

The image shown below for the degradation of TCE/PCE levels after adding VaporRemed on 12/4/2019.

These numbers allowed us to extrapolate a decay model for TCE based on the PCE data (an approximate second-order derivative). The image shown below shows an increase in TCE before falling off to a straight-line first-order decay.

The curve shown above indicates that TCE levels increase before they decrease. This observation is inline with most literature on bio-remediation of PCE that breaksdown into TCE and other compounds as shown here. If we do some “back-of-the-envelope” computations, for each PCE molecule generates a TCE molecule that is fed back into the bio-remediation system. Therefore if we guess that the rate of decay of contamination for TCE is approximately half that of PCE, our guess may not be that far off from the observations on the field :

• PCE - -37%
• TCE - -19%