Complete lab-scale detoxification of groundwater containing 1,2-dichloroethane.
The suspected carcinogenic solvent 1,2-dichloroethane (1,2-DCA) is the most abundant chlorinated C(2) groundwater pollutant on earth. However, an efficient reductive in situ detoxification technology for this compound is not known. Detoxification results of 1,2-DCA with the recently isolated anaerobic bacterium Desulfitobacterium dichloroeliminans strain DCA1 are presented. First, it was verified that strain DCA1 could compete for nutrients in the presence of fast-growing Enterococcus faecalis; the latter was observed in the enrichment culture from which strain DCA1 was isolated. Subsequently, lab-scale bioaugmentation of the strain to groundwater containing 40 mg 1,2-DCA/l indicated that the bacterium has strong metabolic activity under prevailing environmental conditions, converting the pollutant into ethene. During exponential growth, the maximum 1,2-DCA dechlorination rate exceeded 350 nmol chloride released per min per mg total bacterial protein. Growth and dechlorination within the community with autochthonous bacteria indicated a high competitive strength of strain DCA1. Interestingly this dechlorination process does not produce any toxic byproducts, such as vinyl chloride. Furthermore, complete groundwater detoxification happens within a short time-frame (days) and is robust in terms of bacterial competition, oxygen tolerance, high ionic strength, and pH range.
De Wildeman
S
S
Laboratory of Microbial Ecology and Technology, Ghent University, Faculty of Agricultural and Applied Biological Sciences, Coupure Links 653, 9000 Ghent, Belgium.
Linthout
G
G
Van Langenhove
H
H
Verstraete
W
W
D001673:Biodegradation, Environmental; D002712:Chlorides / Q000378:metabolism; D045858:Desulfitobacterium / Q000254:growth & development* / Q000378:metabolism*; D005025:Ethylene Dichlorides / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism; D007700:Kinetics; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D014877:Water Pollution, Chemical
D002712:Chlorides; D005025:Ethylene Dichlorides; D005030:Ethylenes; D014874:Water Pollutants, Chemical; C024565:ethylene dichloride; C036216:ethylene