Table 5-24. DHA data for column degradation III.


Time Column 1 Column 2 Column 3

 AVG. ST.ER. AVG. ST.ER. AVG. ST.ER.
day mg/l/day ( % ) mg/l/day ( % ) mg/l/day ( % )
 -3 -3 -3
0 3.07xl0- 61.6 3.07xl03 18.2 3.36x03 7.7
5 8.56x0-3 23.9 1.45x1 2 16.1 1.42x10- 2.9
 -2 -2 -2
16 2.13x10- 19.6 4.09x10 1.1 2.58x10 31.0
 -2 -2 -2
43 3.45x10 17.4 1.08x10 14.3 1.42x10 3.1



 As in previous experiments, phenol degraded rapidly,

the half-life was about 11 hours for all three columns.

2,4-Dichlorophenol and PCP both degraded slowest in anoxic

conditions (column #1) while the system that amended with

hydrogen peroxide (column #3) degraded fastest but not by a

wide margin. The DHA data correlated generally well with

the degradation data. In column #1 anoxicc conditions) the

microbial activities increased consistently but were lower

than the other two systems except at the end of the

experiment. However, between the two aerobic conditions

(columns #2 and #3) the DHA data did not show significant

difference. Column #2 demonstrated an unusual weak sorption

of PCP, but the reason is unclear.

 The results of this experiment revealed that the three

phenolic compounds degrade in both aerobic and anoxic

conditions, but the degradation is less effective in an

anoxic condition. The microbial populations in anoxic

conditions also build up slower than in aerobic conditions.