Fig. 3 Adsorption isotherms of (a) SO4 and (b) SeO4 in the presence and absence of CO3. Lines are Langmuir fits determined according to the normal nonlinear least squares (NLLS) regression outlined by Schulthess and Dey (1996) with the following parameter values: SO4:
and
; SO4 + CO3:
and
; SeO4:
and
; SeO4 + CO3:
and
;
. Note that the vertical NLLS regression yields nearly identical results