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Environ Sci Technol

Title:		Bioaugmentation for treatment of dense non-aqueous phase liquid in fractured sandstone blocks
Author(s):		Schaefer CE; Towne RM; Vainberg S; McCray JE; Steffan RJ;
Address:		"Shaw Environmental, Inc., Lawrenceville, New Jersey 08648, USA. charles.schaefer@shawgrp.com"
Journal Title:		Environ Sci Technol
Year:		2010
Volume:		44
Issue:		13
Page Number:		4958 - 4964
DOI:		10.1021/es1002428
ISSN/ISBN:		0013-936X (Print) 0013-936X (Linking)
Abstract:		"Laboratory experiments were performed in discretely fractured sandstone blocks to evaluate the use of bioaugmentation to treat residual dense non-aqueous phase liquid (DNAPL) tetrachloroethene (PCE). Significant dechlorination of PCE and growth of Dehalococcoides spp. (DHC) occurred within the fractures. DNAPL dissolution was enhanced during bioaugmentation by up to a factor of approximately 3.5, with dissolved PCE concentrations at or near aqueous solubility. The extent of dechlorination and DNAPL dissolution enhancement were dependent upon the fracture characteristics, residence time in the fractures, and dissolved concentration of PCE. No relationship was observed between planktonic DHC concentrations exiting the fracture and the observed extents of PCE dechlorination and DNAPL dissolution. Measured planktonic DHC concentrations exiting the fracture increased with increasing flow rate and bioaugmentation dosage, suggesting that these parameters may be important for distribution of DHC to treat dissolved chlorinated ethenes migrating downgradient of the DNAPL source. Bioaugmentation dosage, for the DHC dosages and conditions studied, did not have a measurable impact on DNAPL dissolution or dechlorination within the fractures themselves. Overall, these results indicate that bioaugmentation may be a viable remedial option for treating DNAPL sources in bedrock"
Keywords:		"Arizona Chloroflexi/*metabolism Colorado Geological Phenomena Models, Chemical Solubility Tetrachloroethylene/*chemistry Trichloroethylene/chemistry Volatile Organic Compounds Water Pollutants, Chemical/chemistry Water Purification/methods;"
Notes:		"MedlineSchaefer, Charles E Towne, Rachael M Vainberg, Simon McCray, John E Steffan, Robert J eng Research Support, Non-U.S. Gov't 2010/06/08 Environ Sci Technol. 2010 Jul 1; 44(13):4958-64. doi: 10.1021/es1002428"