Table 2 Summary of the sorption curve evaluation. Curve types were classified after Giles and Smith (1974). M10 = sorbed metal concentration in the samples equilibrated with the solution containing 10 mmol/L initial metal concentrations; Qm Langmuir maximum saturated monolayer capacity; b Langmuir constant related to the affinity between adsorbent and adsorbate; RL Langmuir separation factor; KF Freundlich constant related to sorption capacity; n Freundlich exponent. Relating equations are given in the supplementary material

From: Effect of pedogenic iron-oxyhydroxide removal on the metal sorption by soil clay minerals

    Langmuir Freundlich
Sample Curve type M10 Qm b R2 RL range KF n R2
(mmol/kg) (mmol/kg) (L/mmol)    (mmol/kg)   
Cadmium
LB L1 12.69 16.98 0.29 0.99 0.97-0.27 3.84 0.55 0.99
LBDCB L2 4.23 4.33 2.37 0.98 0.82-0.04 2.53 0.27 0.92
PC H2 21.54 22.23 142.16 0.99 0.07-0.001 20.29 0.16 0.78
PCDCB H1 11.40 9.26 84.56 0.71 0.11-0.001 7.77 0.14 0.89
Copper
LB L1 13.77 15.25 0.84 0.99 0.93-0.11 6.26 0.39 0.98
LBDCB L1 12.75 12.54 5.21 0.99 0.66-0.02 8.50 0.24 0.87
PC H1 88.31 85.59 9.23 0.93 0.53-0.01 61.87 0.21 0.99
PCDCB H1 53.18 48.47 8.85 0.91 0.55-0.01 33.96 0.21 0.98
Lead
LB L2 32.03 33.57 2.33 0.99 0.82-0.04 19.04 0.31 0.94
LBDCB L1 41.81 41.92 2.36 0.98 0.82-0.04 23.36 0.29 0.97
PC HC 273.79 523.04 3.26 0.97 0.76-0.03 486.85 0.56 0.99
PCDCB HC 313.35 1351.17 0.27 0.99 0.97-0.24 286.97 0.83 1.00
Zinc
LB L1 7.87 8.42 0.92 0.99 0.92-0.10 3.47 0.40 0.94
LBDCB L1 6.01 6.71 0.79 0.87 0.93-0.12 2.98 0.30 0.97
PC H2 13.42 13.60 7.47 0.81 0.04-0.0004 10.09 0.14 0.96
PCDCB H2 7.75 8.07 2.63 0.75 0.06-0.0006 5.46 0.12 0.95