Table 3.

Kinetic parameters for the effect of SG dye concentration on adsorption by GWTW.

Concentration of SG dye, mg L−1
Parameters	168.0	345.0	495.0	635.0
Pseudo-first order model
qe, (mg·g−1)	29.18	59.02	84.82	102.4
k1(min−1)	0.380	0.297	0.258	0.233
R2	0.9660	0.9214	0.9267	0.9252
SE	2.178	6.075	8.462	10.381
Pseudo-second order model
qe(mg·g−1)	31.31	62.93	90.76	110.0
k2(mg−1·g·min−1)	0.020	0.007	0.004	0.003
R2	0.9901	0.9690	0.9745	0.9754
SE	1.176	3.819	4.996	5.956
Elovich model
Α (mg·g−1·min−1)	613.0	871.2	655.0	502.4
Β (g· mg−1)	0.291	0.150	0.096	0.075
R2	0.9994	0.9990	0.9993	0.9994
SE	0.272	0.693	0.846	0.957
Hyperbolic tangent model
qe(mg·g−1)	38.86	76.41	110.7	135.9
teHT(min)	110	132	167	191
nHT	0.164	0.180	0.202	0.229
R2	0.9928	0.9941	0.9996	0.9992
SE	0.999	0.999	0.997	1.000
Modified Lagergren model
Qmax, (mg·g−1)	33.61	68.93	98.76	127.00
k1(min−1)	0.248	0.184	0.163	0.119
t1/2(min)	2.8	3.8	4.2	7.4
R2	0.9517	0.7835	0.8005	0.6781
SE	3.759	9.432	13.065	20.148
Diffusion – chemisorption model
qe(mg·g−1)	36.51	73.15	107.1	131.8
KDC(mg (g·min0.5)−1)	28.97	46.21	59.24	64.30
ki	22.99	29.19	32.77	31.36
R2	0.9979	0.9931	0.9961	0.9975
SE	0.539	1.803	1.949	1.901