title: Chitin and corncobs as electron donor sources for the reductive dechlorination of tetrachloroethene.
abstract: Chitin, corncobs, and a mixture of chitin and corncobs were tested as potential electron donor sources for stimulating the reductive dechlorination of tetrachloroethene (PCE). Semi-batch, sand-packed columns were used to evaluate the donors with aerobic and anaerobic groundwaters containing varying degrees of alkalinity. In all experiments, acetate and butyrate were the dominant fatty acids produced, although propionate, valerate, formate, and succinate were also detected. From a multivariable regression analysis on the data, the presence of chitin, limestone, and dechlorinating culture inoculum were determined to be the most positive predictors of dechlorination activity. Chitin fermentation products supported the degradation of PCE to trichloroethene (TCE), cis-1,2-dichloroethene (DCE), and vinyl chloride (VC), even in columns containing PCE DNAPL, whereas dechlorination activity was not observed in any of the columns containing corncobs alone. The longevity and efficiency of chitin as an electron donor source demonstrates its potential usefulness for passive, in situ field applications.
authors.affiliation: Department of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, 3215 Newmark Civil Engineering Laboratory, 205 N. Mathews Avenue, Urbana, IL 61801, USA. rbrennan@engr.psu.edu
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Brennan
authors.forename: Robert A
authors.initials: RA
authors.lastname: Sanford
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Werth
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D002686:Chitin / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry / Q000378:metabolism*; D004579:Electron Transport; D005285:Fermentation; D010084:Oxidation-Reduction; D012044:Regression Analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013750:Tetrachloroethylene / Q000378:metabolism*; D014881:Water Supply; D003313:Zea mays / Q000737:chemistry*
chemical_list: D012989:Soil Pollutants; D002686:Chitin; D002713:Chlorine; D013750:Tetrachloroethylene