Biodegradation of low concentrations of 1,2-dibromoethane in groundwater is enhanced by phenol
- 388 Downloads
The lead scavenger 1,2-dibromoethane (EDB), a former additive to leaded gasoline, is a common groundwater contaminant, yet not much knowledge is available for its targeted bioremediation, especially under in situ conditions. The study site was an aviation gas spill site, which, although all hydrocarbons and most of the EDB were remediated in the mid-1990s, still exhibits low levels of EDB remaining in the groundwater (about 11 μg EDB/l). To evaluate the effect of phenol on biostimulation of low concentration of EDB, microcosms were established from an EDB-contaminated aquifer. After 300 days at environmentally relevant conditions (12 ± 2 °C, static incubation), EDB was not significantly removed from unamended microcosms compared to the abiotic control. However, in treatments amended with phenol, up to 80 % of the initial EDB concentration had been degraded, while added phenol was removed completely. Microbial community composition in unamended and phenol-amended microcosms remained unchanged, and Polaromonas sp. dominated both types of microcosms, but total bacterial abundance and numbers of the gene for phenol hydroxylase were higher in phenol-amended microcosms. Dehalogenase, an indicator suggesting targeted aerobic biodegradation of EDB, was not detected in either treatment. This finding suggests phenol hydroxylase, rather than a dehalogenation reaction, may be responsible for 1,2-dibromoethane oxidation under in situ conditions. In addition, biostimulation of EDB is possible through the addition of low levels of phenol in aerobic groundwater sites.
KeywordsBiostimulation Cometabolism 1,2-dibromoethane Groundwater Natural attenuation Phenol
This research was funded by the Air Force Center for Engineering and the Environment (AFCEE). We thank AFCEE/CH2M HILL for providing us with soil core and groundwater samples.
- Air Force Center for Engineering and the Environment (2007) Massachusetts Military Reservation Cape Code, Groundwater Plume Maps & Information Booklet.Google Scholar
- Aronson D, Howard PH (2008) The Environmental Behavior of Ethylene Dibromide and 1,2-Dichloroethane in Surface Water, Soil, and Groundwater. Publication 4774. American Petroleum Institute, Washington, D.C.Google Scholar
- Dionisi HM, Chewning CS, Morgan KH, Menn F, Easter JP, Sayler GS (2004) Abundance of dioxygenase genes similar to Ralstonia sp. strain U2 nagAc is correlated with naphthalene concentrations in coal tar-contaminated freshwater sediments. Appl Environ Microbiol 70:3988–3995. doi: 10.1128/AEM.70.7.3988-3995.2004 PubMedCentralPubMedCrossRefGoogle Scholar
- Environmental Protection Agency US (1995) Method 504.1. 1,2-dibromoethane (EDB), 1,2-dibromo-3-chloropropane (DBCP), and 1,2,3-trichloropropane (123TCP) in water by microextraction and gas chromatography, Revision 1.1. United States Environmental Protection Agency, Washington D.CGoogle Scholar
- Futamata H, Nagano Y, Watanabe K, Hiraishi A (2005) Unique kinetic properties of phenol-degrading Variovorax strains responsible for efficient trichloroethylene degradation in a chemostat enrichment culture. Appl Environ Microbiol 71:904–911. doi: 10.1128/AEM.71.2.904-911.2005 PubMedCentralPubMedCrossRefGoogle Scholar
- Hartzell KE, Burton CD, Leeson A (2001) Biodegradation of ethylene dibromide through cometabolic mechanisms. In: Leeson A, Johnson PC, Hinchee RE, Semprini L, Magar VS (eds) In situ aeration and aerobic remediation: Sixth International In Situ and On-Site Bioremediation Symposium, vol 10. Battelle Press, Columbus Ohio, pp 193–199Google Scholar
- Hatzinger PB, Streger S, Begley JF, Forbes R (2011) Enhancing aerobic biodegradation of 1,2-dibromoethane and 1,2-dichloroethane using ethane gas. International Symposium on Bioremediation and Sustainable Environmental Technologies. Nevada, BattelleGoogle Scholar
- McKeever R, Sheppard D, Nüsslein K, Baek K, Rieber K, Ergas SJ, Forbes R, Hilyard M, Park C (2012) Biodegradation of ethylene dibromide (1,2-dibromoethane [EDB]) in microcosms simulating in situ and biostimulated conditions. J Haz Materials 209–210:92–98. doi: 10.1016/j.jhazmat.2011.12.067 CrossRefGoogle Scholar
- MDEP, Massachusetts Department of Environmental Protection (2004) Current Regulatory Limit: Ethylene Dibromide (EDB), http://www.mass.gov/dep/water/drinking/standards/edibrom.htm.
- U.S. Environmental Protection Agency (1983a) Ethylene dibromide: decision and emergency order suspending registration of pesticide products containing ethylene dibromide for use as a soil fumigant. Fed Regist 48:46228–46248Google Scholar
- U.S. Environmental Protection Agency (1983b) Methods for Chemical Analysis of Water and Wastes, Method 420.1. United States Environmental Protection Agency, Washington D.CGoogle Scholar
- Wilson JT, Banks K, Earle RC, He Y, Kuder T, Adair C ( 2008) Natural attenuation of the lead scavengers 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) at motor fuel release sites and implications for risk management. USEPA National Risk Management Research Laboratory. EPA 600/R-08/107 http://www.epa.gov/ahaazvuc/pubs/reports.html.