Also note that the author terminated all of these tests due to a failure of the oven used to maintain the samples at 50 C. Due to these experimental limitations, the tests without sludge were approximately 2500 hours in duration. This preliminary analysis might suggest that the reaction was not due to copper. However, a number of significant differences exist between the conditions in this test and the conditions under which this rate constant was developed. In particular, the rate constant was developed from tests in which only soluble NaTPB was present and at lower hydroxide concentrations. These results taken as a whole indicate that the observed decomposition shown in Figure 1 agrees with a copper catalysis decomposition reaction.
Additional insight results from comparing the boron data to the phenol data.
Figure 2 contains a plot of the phenol data from these experiments. Inspection of Figure 2 indicates an identical trend in the phenol data as seen in the boron data. Furthermore, the average phenol rise in the tests with sludge at 50 C measured 7 mM. Note that the average boron rise for the same tests measured 6.1 mM. The standard deviations of these two average values indicate that these two values agree within experimental error. This agreement suggests that phenol forms from a single stage in the decomposition reaction. The current data does not allow one to identify the reaction step involved.