TABLE 1.

Chemical properties of groundwater in wells of treatment area before and after remediation and in control well FW106

WellaStatusbChemical composition of groundwater
pHNitrate (mM)Sulfate (mM)Cl (mM)S2− (mM)Al (mM)Ca (mM)Mg (mM)Mn (mM)Fe (mM)U (μM)% U(IV)d
FW104A3.83208.0031.0012.000.0013.6059.1011.40NA0.11139.000
B5.750.001.182.340.300.020.650.320.070.030.5761
FW101-2A3.78182.0018.209.700.0016.7057.4012.50NA0.11135.000
B6.230.001.072.320.430.000.670.300.070.030.1551
FW102-3A3.80137.003.208.800.00NAc27.906.70NANA150.000
B6.230.001.102.310.360.010.620.310.080.050.0617
FW102-2A4.20271.003.629.900.00NA57.9011.96NANA47.000
B6.450.001.012.320.160.010.800.310.080.040.0830
FW101-3A3.95113.0031.006.400.006.3036.707.50NA0.09134.000
B6.100.001.202.300.110.010.670.350.060.010.1053
FW026A3.22159.006.208.000.0018.2025.106.802.270.17158.000
B5.740.011.202.360.040.020.640.320.070.010.53<10
FW106Control3.6061.9025.4013.300.00NA8.961.05NA0.03128.00NA
  • a Wells are arranged according to their descending hydraulic connection to the injection well (FW104) based on the tracer studies.

  • b A, before remediation (samples were taken in February to April, 2002) except for FW106 (day 278); B, after biostimulation on day 773 (4 October 2005).

  • c NA, data not analyzed.

  • d Detection limit for U(IV) is 10% of total U in XANES (48).