title: In situ aerobic cometabolism of chlorinated solvents: a review.
abstract: The possible approaches for in situ aerobic cometabolism of aquifers and vadose zones contaminated by chlorinated solvents are critically evaluated. Bioaugmentation of resting-cells previously grown in a fermenter and in-well addition of oxygen and growth substrate appear to be the most promising approaches for aquifer bioremediation. Other solutions involving the sparging of air lead to satisfactory pollutant removals, but must be integrated by the extraction and subsequent treatment of vapors to avoid the dispersion of volatile chlorinated solvents in the atmosphere. Cometabolic bioventing is the only possible approach for the aerobic cometabolic bioremediation of the vadose zone. The examined studies indicate that in situ aerobic cometabolism leads to the biodegradation of a wide range of chlorinated solvents within remediation times that vary between 1 and 17 months. Numerous studies include a simulation of the experimental field data. The modeling of the process attained a high reliability, and represents a crucial tool for the elaboration of field data obtained in pilot tests and for the design of the full-scale systems. Further research is needed to attain higher concentrations of chlorinated solvent degrading microbes and more reliable cost estimates. Lastly, a procedure for the design of full-scale in situ aerobic cometabolic bioremediation processes is proposed.
authors.affiliation: Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Via Terracini 28, 40131 Bologna, Italy. Electronic address: dario.frascari@unibo.it.
authors.forename: Dario
authors.initials: D
authors.lastname: Frascari
authors.affiliation: Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Via Terracini 28, 40131 Bologna, Italy. Electronic address: giulio.zanaroli@unibo.it.
authors.forename: Giulio
authors.initials: G
authors.lastname: Zanaroli
authors.affiliation: Geo-Environmental and Resources Research Center, Department of Mining Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; Centre for Natural Resources and the Environment (CERENA), Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. Electronic address: asdanko@fe.up.pt.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Danko
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D060587:Groundwater / Q000382:microbiology*; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism*; D012997:Solvents; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D006843:Hydrocarbons, Chlorinated; D012997:Solvents; D014874:Water Pollutants, Chemical
keywords: Aerobic cometabolism; Chlorinated solvents; In situ bioremediation; Modeling; Technology selection