Due to the low Ceq values, the Kf values
were not always within the Kd,minKd,max range. Therefore, the Kf
was lower than the Kd,min for the high affinity isotherms (i.e.,
MOW-Pb and GW-Pb) and higher than the Kd,max for the sigmoidal-
shape isotherms (i.e., MOW-Cu).