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Properties of whole soils, untreated, and treated water-dispersible clay (WDC).

 
OC† Fed Feo CEC SA
g kg−1 mg g−1 cmolc kg−1 m2 g−1
Catlin silt loam 42.3 4.77 4.95 39
Kenner muck 353.5 1.73 1.82 122
Benndale fine sandy loam 8.9 0.88 0.76 11
Catlin WDC 51.5 20.24 9.24 95 18.1
Catlin WDC- OC 13.1 10.05 8.94 68 59.1
Catlin WDC- OC- Fed 9.2 0.92 1.48 64 50.3
Catlin WDC- OC- Feo 14.5 8.29 6.16 60 52.1
Catlin WDC- Feo 48.8 7.87 5.53 84 19.2
Kenner WDC 292.0 1.88 2.27 158 6.1
Kenner WDC- OC 49.5 3.55 5.49 55 14.0
Kenner WDC- OC- Fed 43.7 0.34 1.03 48 19.6
Kenner WDC- OC- Feo 51.4 2.07 2.36 49 21.5
Kenner WDC- Feo 289.0 0.63 0.93 144 4.0
Benndale WDC 15.7 10.44 4.52 47 55.0
Benndale WDC- OC 5.2 5.32 3.16 46 42.6
Benndale WDC- OC- Fed 4.3 1.28 1.09 36 67.0
Benndale WDC- OC- Feo 5.1 3.91 1.81 44 60.4
Benndale WDC- Feo 11.8 4.97 1.22 42 47.1
OC = organic carbon by combustion after acid treatment; Fed = dithionite-citrate extractable iron, Feo = acid oxalate extractable iron; CEC = cation exchange capacity by sodium acetate method; SA = surface area by nitrogen adsorption.



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Regression parameters for RDX adsorption data for whole soils, untreated, and treated water-dispersible clay (WDC). Best R 2 for the treatment is shown in bold.

 
Linear Freundlich Langmuir
Soil Treatment K d R 2 K f n R 2 Q b R 2
Catlin 2.03 0.994 ** 2.44 0.89 0.995 ** 39.93 0.07 0.990 **
Kenner 36.19 0.993 ** 43.14 0.84 0.978 ** 230.08 0.25 0.973 **
Benndale 0.78 0.992 ** 1.22 0.74 0.961 ** 6.70 0.25 0.930 **
Catlin WDC 4.01 a† 0.999 ** 3.61 0.77 0.840 ** 1.71 16.38 0.517 *
WDC- OC 1.72 d 0.985 ** 1.37 1.12 0.803 * 0.16 17.97 0.124 ns
WDC- OC- Fed 2.02 d 0.996 ** 1.98 0.63 0.552 ns‡ 0.32 −3.37 0.849 *
WDC- OC- Feo 2.54 c 0.995 ** 3.49 0.60 0.843 * −3.37 1.46 0.596 ns
WDC- Feo 3.46 b 0.998 ** 3.64 0.81 0.906 * 1.71 9.31 0.712 ns
Kenner WDC 21.95 a 0.997 ** 26.80 0.89 0.995 ** 560.32 0.05 0.995 **
WDC- OC 3.07 b 0.959 ** 2.44 1.13 0.812 ** 0.95 −0.20 0.346 ns
WDC- OC- Fed 2.72 b 0.920 ** 1.88 1.20 0.790 ** 1.87 −0.25 0.284 ns
WDC- OC- Feo 2.99 b 0.910 ** 1.36 1.36 0.860 ** 12.78 −17.78 0.000 ns
WDC- Feo 19.02 a 0.985 ** 22.81 0.91 0.973 ** 1382.15 0.02 0.974 **
Benndale WDC 1.28 abcd 0.898 ** 1.99 0.56 0.621 ** 11.25 −0.30 0.351 *
WDC- OC 1.44 bc 0.961 ** 2.53 0.57 0.702 ** −5.49 0.81 0.376 *
WDC- OC- Fed 0.85 d 0.892 ** 0.68 1.04 0.775 ** −0.50 −0.53 0.966 **
WDC- OC- Feo 0.97 cd 0.768 ** 1.09 0.80 0.846 ** 4.91 0.63 0.891 **
WDC- Feo 1.78 ab 0.959 ** 1.82 0.69 0.606 ** 1.00 −3.39 0.557 **
* - regression significant at 95%.
** - regression significant at 99%.
Numbers followed by the same letter within soil are not different at 95% level.
ns- regression not significant at 95%.



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Regression parameters for TNT adsorption data for whole soils, untreated, and treated water-dispersible clay (WDC). Best R 2 for the treatment is shown in bold.

 
Linear Freundlich Langmuir
Soil Treatment K d R 2 K f n R 2 Q b R 2
Catlin 17.90 0.932 ** 32.67 0.60 0.957 ** 119.05 0.46 0.982 **
Kenner 285.23 0.831 ** 499.01 0.63 0.894 ** 1866.00 0.44 0.972 **
Benndale 1.77 0.976 ** 2.78 0.73 0.975 ** 13.71 0.29 0.946 **
Catlin WDC 20.61 b† 0.939 ** 48.48 0.48 0.995 ** 114.29 1.01 0.973 **
WDC- OC 8.90 d 0.941 ** 21.17 0.53 0.955 ** 69.89 0.48 0.981 **
WDC- OC- Fed 12.91 c 0.961 ** 27.97 0.56 0.991 ** 91.51 0.52 0.979 **
WDC- OC- Feo 13.20 c 0.964 ** 28.35 0.56 0.987 ** 92.64 0.52 0.984 **
WDC- Feo 26.40 a 0.863 ** 71.64 0.40 0.931 ** 140.45 1.66 0.974 **
Kenner WDC 59.13 a 0.979 ** 111.31 0.54 0.916 ** 258.24 0.97 0.772 **
WDC- OC 10.56 b 0.952 ** 19.60 0.62 0.780 ** 71.59 0.42 0.670 **
WDC- OC- Fed 12.80 b 0.976 ** 21.44 0.70 0.877 ** 102.63 0.29 0.720 **
WDC- OC- Feo 10.28 b 0.978 ** 21.12 0.59 0.891 ** 74.19 0.46 0.781 **
WDC- Feo 59.34 a 0.972 ** 115.64 0.51 0.871 ** 239.65 1.25 0.670 **
Benndale WDC 4.69 bc 0.971 ** 7.88 0.73 0.977 ** 61.88 0.15 0.983 **
WDC- OC 2.51 e 0.964 ** 5.53 0.58 0.948 ** 23.58 0.31 0.954 **
WDC- OC- Fed 3.86 cde 0.924 ** 6.83 0.68 0.907 ** 34.10 0.27 0.927 **
WDC- OC- Feo 3.74 d 0.995 ** 5.19 0.81 0.983 ** 45.54 0.14 0.961 **
WDC- Feo 6.43 a 0.979 ** 12.42 0.61 0.928 ** 41.03 0.51 0.727 **
** - regression significant at 99%.
Numbers followed by the same letter within the soil are not different at 95% level.



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Average adsorption coefficients (mL g−1) for TNT and RDX in water-dispersible clay (WDC) before (logK d) and after normalization for organic carbon (logK OC), acid oxalate extractable iron (logK Feo), and dithionite-citrate extractable iron (logK Fed).

 
TNT RDX
Avg. Standard deviation % Standard deviation Avg. Standard deviation % Standard deviation
logK d 1.04 0.41 39 0.44 0.41 93
logK OC 2.65 0.28 11 2.04 0.24 12
logK Feo 0.41 0.65 159 0.12 0.66 537
logK Fed 0.34 0.82 242 0.05 0.86 1746