Surge block method for controlling well clogging and sampling sediment during bioremediation.
A surge block treatment method (i.e. inserting a solid rod plunger with a flat seal that closely fits the casing interior into a well and stocking it up and down) was performed for the rehabilitation of wells clogged with biomass and for the collection of time series sediment samples during in situ bioremediation tests for U(VI) immobilization at a the U.S. Department of Energy site in Oak Ridge, TN. The clogging caused by biomass growth had been controlled by using routine surge block treatment for 18 times over a nearly four year test period. The treatment frequency was dependent of the dosage of electron donor injection and microbial community developed in the subsurface. Hydraulic tests showed that the apparent aquifer transmissivity at a clogged well with an inner diameter (ID) of 10.16 cm was increased by 8-13 times after the rehabilitation, indicating the effectiveness of the rehabilitation. Simultaneously with the rehabilitation, the surge block method was successfully used for collecting time series sediment samples composed of fine particles (clay and silt) from wells with ID 1.9-10.16 cm for the analysis of mineralogical and geochemical composition and microbial community during the same period. Our results demonstrated that the surge block method provided a cost-effective approach for both well rehabilitation and frequent solid sampling at the same location.
Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA; Center for Sustainable Development and Global Competitiveness, Stanford University, Stanford, CA 94305-4020, USA. Electronic address: wei-min.wu@stanford.edu.
Wei-Min
WM
Wu
David B
DB
Watson
Jian
J
Luo
Jack
J
Carley
Tonia
T
Mehlhorn
Peter K
PK
Kitanidis
Phlip M
PM
Jardine
Craig S
CS
Criddle
D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D001965:Bromides / Q000302:isolation & purification; D019015:Geologic Sediments / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013997:Time Factors; D014501:Uranium / Q000302:isolation & purification; D014875:Water Pollutants, Radioactive / Q000302:isolation & purification; D060986:Water Wells / Q000737:chemistry*
D001965:Bromides; D014875:Water Pollutants, Radioactive; D014501:Uranium
Bioremediation; Clogging; Sediment sampling; Subsurface; Surge block; Well rehabilitation