by sludge amendment. Glucose and sodium acetate seemed to

have little influence, and the bacteria that were acclimated

to both 2,4-DCP and PCP were not significantly effective in

aiding phenol degradation.

 Table 5-17, Table 5-18 and Figures 5-22 through 5-27

show the results for PCP degradation in multi-compound

conditions. For the same reason as described in the PCP

single-compound degradation study, a weighted average method

was used to calculate the rates and to construct the

figures. The correlation coefficient (R ) values for some

samples in the lower concentration range were low,

presumably because the deviations caused by analytical

problems were magnified at the lower initial concentrations

relative to at the higher initial concentrations. Less

weight was put on these samples when assessing the results.

Also, #407 was discontinued at t=27 days when the sample was

contaminated with PCP standard solution. Therefore, the KBD

and tl/2 values of #407 cannot be compared with other

samples. Notice the samples #402 and #410 in Table 5-17

that the PCP degradation rates in multi-compound systems

were significantly greater than in single-compound systems.

The average half-life for plain soil samples was about 85

days, compared to 120 days in #302 and #308 in Table 5-14

when PCP was in single-compound systems. This may be that

PCP was co-metabolized by the bacterial populations which

were increased by metabolizing phenol as a primary

substrate.