Results of a Multi-Site Field Treatability Test for Bioslurping: A Comparison of LNAPL Rates Using Vacuum-Enhanced Recovery (Bioslurping), Passive Skimming, and Pump Drawdown Recovery Techniques.
Abstract : Bioslurping is a new dynamic technology designed to efficiently recover free-floating petroleum hydrocarbons (free product) from the subsurface while simultaneously enhancing natural biodegradation of petroleum hydrocarbons in the vadose zone. Bioslurping is a vacuum-enhanced fluids pumping technology that simultaneously extracts groundwater, free product, and soil gas in the same process stream. The U.S. Air Force has initiated a multi-site program to evaluate the widespread application of bioslurping at free product-contaminated Air Force sites. The Air Force Bioslurper Initiative is designed to access the field application of the bioslurping technology at 36 Air Force sites. The field studies are designed to evaluate the efficacy of bioslurping for the recovery of free-floating fuel (free product) and to evaluate the potential for bioventing to enhance natural biodegradation of petroleum contaminants. The technical approach for conducting the bioslurper pilot tests includes assessing the geologic and hydrologic characteristics of each site, free-product baildown testing in site monitoring wells, soil gas analysis, and a bioslurper pump test. Bioslurping free-product recovery efficiency is compared to conventional skimming and dual-pump free-product recovery technologies, and bioventing potential is assessed via in situ respiration testing. The Air Force field program was initiated in July 1994. At the time of this writing, seven field tests have been completed. At each site bioslurping has yielded the highest LNAPL recovery rate. This paper presents a summary of LNAPL recovery data to date. Operational issues such as permitting and treatment of vapor and wastewater discharge will be discussed.
Test plan and technical protocol for bioslurping
Bioslurping is a new dynamic technology designed to efficiently recover free-floating petroleum hydrocarbons (free product) from the subsurface while simultaneously enhancing natural biodegradation of petroleum hydrocarbons in the vadose zone. Bioslurping is a vacuum-enhanced fluids-pumping technology that simultaneously extracts groundwater, free product, and soil gas in the same process stream. The US Air Force has initiated a multisite program to evaluate the widespread application of bioslurping at free-product-contaminated Air Force sites. The Air Force Bioslurper Initiative is designed to assess the field application of the bioslurping technology at 23 Air Force sites. The field studies are designed to evaluate the efficacy of bioslurping for the recovery of free-floating fuel (free product) and to evaluate the potential for bioventing to enhance natural biodegradation of petroleum contaminants. The technical approach for conducting the bioslurper pilot tests includes assessing the geologic and hydrologic characteristics of each site, free-product baildown testing in site monitoring wells, soil gas analysis, and a bioslurper pump test. The efficiency of bioslurping is compared to that of conventional skimming and dual-pump free-product recovery technologies. Bioventing potential is assessed via in situ respiration testing.
Representations and computations of {2, 3~} and {2, 4~}-inverses in indefinite inner product spaces
We investigate full-rank representations of { 2 , 3 ~ } and { 2 , 4 ~ } -inverses with prescribed rank as well as with prescribed range and null space in an indefinite inner product space. In certain particular cases we obtain new results or generalizations related with { 2 , 3 } and { 2 , 4 } -inverses in a Hilbert (unitary) space. Direct and iterative methods for computing { 2 , 3 ~ } and { 2 , 4 ~ } -inverses in an indefinite inner product space are developed. Numerical examples with different metric matrices are presented.