NATO/CCMS Pilot Study Evaluation of Demonstrated and ... - CLU-IN

NATO/CCMS Pilot Project on Contaminated Land and Groundwater (Phase III) January 2002
at the site of investigation. Interception of the HCH/Chlorobenzene/benzene plume is needed to protect a
canal located at the boundary of the site.
3. DESCRIPTION OF PROCESS
Chlorinated solvent site. Laboratory experiments identified that a mixture of electron-donors is most
suitable to enhance the in situ reductive dechlorination. In situ full-scale demonstration of enhanced
anaerobic degradation in the source zone designed for complete reductive dechlorination is currently
performed. The same technology is considered to be applied later at the head of the plume in terms of a
treatment zone.
Oil refinery site. Bench scale experiments have been finished and established: i) optimal grain-size and
packing density for the porous media used in the trench, ii) optimal oxygen supply rates to sufficiently
initiate aliphatic hydrocarbon biodegradation and to minimise clogging with iron (III) oxides. Three
different technologies are being tested at pilot scale: two gravel filled reactive trenches with biosparging
units and one biosparging fence, without excavation of the soil. Each pilot application has a length of 40
m, and a depth of 4 meters.
Aromatic hydrocarbon (BTEX) sites. Microcosms were used to investigate possibilities to stimulate
biodegradation of benzene and TEX compounds. Especially, addition of nitrate and low amounts of
oxygen to the anaerobic systems appears to be the appropriate way to create down-stream biostimulated
zones. Pilot demonstration tests are currently performed. One pilot test is a biostimulated zone with
dimensions of 10 to 10 meters.
Chlorinated pesticide site. A bioactivated zone as an alternative to conventional large-scale pump-andtreat
is currently being investigated. Laboratory process research indicated that a combination of
anaerobic-microaerophilic in-situ stimulation in a bioactivated zone is the most feasible approach.
Preparations are being made to incorporate the installation of the biotreatment zone in new building
activities ate the site.
4. RESULTS AND EVALUATION
The status of most projects is that they recently have entered a pilot or a full-scale phase. First
evaluations of technology performance are to be expected at the end of 1999.
5. COSTS
In a separate cost-analyses project, the costs of investment and operation of various bioscreen
configurations (i.e. the funnel-and-gate TM , the reactive trench and the biostimulated zone configuration) is
being evaluated for various sites. The results indicate that biotreatment zones are in most cases the
cheapest and most flexible approach, whereas funnel-and-gate TM systems and reactive trenches have a cost
level comparable to conventional pump-and-treat. Biotreatment zones have therefore the greatest market
perspective, whereas funnel-and-gate TM systems and reactive trenches can be used when a high degree of
protection is required or when these approaches can be integrated with other building activities planned at
the site.
6. REFERENCES AND BIBLIOGRAPHY
1. Bosma, T. N. P., Van Aalst, M.A., Rijnaarts, H.H.M., Taat, J., & Bovendeur, J. (1997) Intrinsic
dechlorination of 1,2-dichloroethane at an industrial site monitoring of extensive in-situ
biotechnological remediation. In: In Situ and On Site Bioremediation, the 4th International
Symposium, New Orleans, Louisiana, April 28-May 1.
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