Environmental Engineering Reference
In-Depth Information
aqueous phase. Data are not shown, but the results were similar to those
shown previously for
P. aeruginosa
strain 64 growing in PAH-contaminated
soil (Figure 7.18). Wash water released five to six times more HMW PAHs
when
P. aeruingosa
strain 64 was present in soil samples vs. no
P. aeruginosa
strain 64 amendment of the soil.
The amount of PAHs released exceeded their aqueous solubility, indi-
cating the solubilizing effect of the biosurfactant. From the experiments, the
amount of biomass used in the inoculation of
P. aeruingosa
strain 64 seemed
to have little effect; therefore, inoculating with the 10
6
cells/g of vermiculite
(added to soil at 2% by weight) appears to yield the optimal effect. Figure
7.20 shows the effects of different concentrations of dried-blood fertilizer on
bacterial growth in PAH-contaminated soil from the SMWT site. Samples
were plated on LB agar with 0.3% glycerol to promote pigment production.
The addition of 2% dried-blood fertilizer worked as well as the 4% concen-
tration, which makes the lower-concentration fertilizer addition more rea-
sonable for field application. In addition, experiments with EPA 505 have
shown that the presence of the dried blood did not affect the ability of the
organisms to degrade PAHs.
7.4.1.4 Vermiculite carrier technology
The survival of
P. aeruginosa
strain 64 on the vermiculite carrier (vs. vermic-
ulite with no added bacteria) when introduced into contaminated soil is
shown in Figure 7.21. Total counts of bacteria increased by three orders of
1.00E + 10
1.00E + 09
1.00E + 08
1.00E + 07
1.00E + 06
0% Dried Blood
0.5% Dried Blood
1% Dried Blood
2% Dried Blood
4% Dried Blood
1.00E + 05
1.00E + 04
0
2
4
6
8
10
12
14
16
Times (days)
Figure 7.20
The effects of varying concentration of dried-blood fertilizer on bacterial
growth in SMWT site soil inoculated with
P. aeruginosa
strain 64.
