Table 3: Comparison of isotherm and ANN models using non-linear regression for Cr(VI) uptake by activated carbon.

Model Parameters Error Functions
RPE MPSD HYBRID
Langmuir qe = 32.3; KL = 0.039 10.991 12.098 21.441
Freundlich KF = 2.874; n = 1.94 13.446 19.325 32.299
Sips qs = 35.15; αs = 0.032; ns = 0.924 11.419 14.250 26.836
Original BET qmBET1 = -18.05; Kb = 1.0628; Cs = -11.34 11.480 17.320 28.892
Modified BET qmBET2 = 18.08; Ks = 0.0937; KL = 0.0055 13.221 17.608 34.570
ANN 1.688 2.061 0.603