Biomedical Engineering Reference
In-Depth Information
Vinyl chloride was finally shown to be completely reduced to ethene by a unique group of
organisms ( Dehalococcoides spp.) (Freedman and Gossett, 1989 ). In the case of chlorinated
solvents, two bacterial groups ( Dehalococcoides and Dehalobacter ) have been relatively well
studied in the laboratory, and in the case of Dehalococcoides , its presence has been correlated
with the ability of the “natural” microbiota to completely degrade chlorinated solvents
(Hendrickson et al., 2002 ). This breakthrough and subsequent research that further revealed
the unique capabilities of this group of bacteria made effective bioaugmentation possible
(Duhamel et al., 2002 ; Cupples et al., 2003 ; He et al., 2003 ). Recognition that complete
dechlorination was achievable even at concentrations near the solubility limit for the most
highly chlorinated compounds led to even greater interest in this process and the potential for
using bioaugmentation to enhance in situ bioremediation of chlorinated solvents (DiStefano
et al., 1991 ; Adamson et al., 2003 ; Stroo et al., 2010 ).
As this volume shows, bioaugmentation has become a more accepted and successful
technique in recent years mainly due to the success with chlorinated solvents. Bioaugmentation
with Dehalococcoides spp. to remediate chlorinated solvents has become a viable commercial
practice and has been used at several hundred sites (Figure 1.2 ). In addition, bioaugmentation
with aerobic bacteria capable of cometabolically degrading chloroethenes has been used
at approximately 150 chlorinated solvent sites (personal communication, Michael Saul,
CL-Solutions, Inc., March 24, 2010). Bioaugmentation with aerobic cometabolic bacteria is
not discussed at length in this volume, largely because of the lack of peer-reviewed literature
describing demonstrations of the process. However, there is growing commercial use and
information on case studies (www.cl-solutions.com; accessed June 18, 2012).
In the case of Dehalococcoides bioaugmentation, it is well-documented that it can improve
bioremediation performance by increasing the rate of biological treatment and decreasing the
WA
4
NH
3
MA
13
OR
9
NY
1
WI
5
SD
3
MI
6
CT
4
PA
5
NJ
12
NE
1
OH
7
IL
4
IN
8
DE
1
UT
2
CA
80
CO
12
VA
2
KS
15
MD
13
KY
2
NC
6
TN - 3
OK
5
SC
14
GA
20
MS
8
Canada (Ontario)
2
TX
13
LA
2
AK
1
Denmark
6
England
2
FL
24
South Africa
2
HI
3
Sweden
1
Figure 1.2. Recent census of bioaugmentation applications using Dehalococcoides spp. for site
cleanup. Figure based on information provided in 2009 by R. J. Steffan (Shaw Environmental
& Infrastructure, Inc., Lawrenceville, NJ), R. L. Raymond, Jr. (Terra Systems, Inc., Wilmington, DE)
and P. C. Dennis (SiREM, Guelph, Ontario, Canada).
Search WWH ::




Custom Search