Adsorptive Removal of Acid Blue 80 Dye from Aqueous Solutions by Cu-TiO₂

Table 5

Isotherm constants of two-, three-, and four-parameter models for AB80 adsorption onto Cu-TiO₂.

Two-parameter models
Langmuir
L mg^−1	0.0465 ± 0.009
mg g^−1	22.23 ± 1.87
	0.994
RMSE	0.259
SSE	0.203
Freundlich
[mg g^−1] [mg L^−1	3.038 ± 1.971
	2.514 ± 0.953
	0.931
RMSE	1.71
SSE	14.62
Halsey
[L g^−1]	16.35 ± 43.79
	2.514 ± 0.953
	0.931
RMSE	1.71
SSE	14.62
Dubinin-Radushkevich
[mol^2 kJ^−2]	26.36
[mg g^−1]	18.14 ± 6.23
	0.89
RMSE	2.136
SSE	22.81
Three-parameter models
Koble-Corrigan
	1
[L mg^−1	0.041 ± 0.05
	0.973 ± 0.75
	0.992
RMSE	0.589
SSE	1.734
Sips
[mg L^−1	0.021 ± 0.007
	0.9802 ± 0.014
[mg g^−1]	21.59 ± 1.05
	0.998
RMSE	0.205
SSE	0.168
Redlich-Peterson
[L mg^−1	0.01223 ± 0.013
	1.183 ± 0.805
[L g^−1]	0.8462 ± 0.579
	0.997
RMSE	0.3163
SSE	0.4002
Toth
[L mg^−1]	0.1
	1.345 ± 0.149
[mg g^−1]	12.55 ± 2.15
	0.9823
RMSE	0.7904
SSE	3.123
Khan
	0.018 ± 0.034
	1.353 ± 0.673
[mg g^−1]	42.65 ± 39.88
	0.996
RMSE	0.362
SSE	0.525
Four-parameter model
Fritz-Schluender
[mg g^−1] [mg L^−1	0.407 ± 0.529
[mg L^−1	0.0226 ± 0.043
	1.336 ± 1.666
	1.302 ± 0.452
	0.999
RMSE	0.233
SSE	0.161