Table 6.

Kinetics parameters for the sorption of Cu²⁺ onto CS-nZVI at various initial Cu²⁺ concentrations.

Initial Concentration
Kinetics Model parameters	10 ppm	50 ppm	100 ppm	150 ppm	200 ppm
Pseudo first-order
qe,exp (mg/g)	4.9859	24.1981	43.8152	61.684	81.77
qe, cal (mg/g)	0.01109	2.1311	2.3147	3.1261	1.5816
k1(min−1)	−0.0161	8.065 × 10−3	−9.212 × 10−4	4.375 × 10−3	1.152 × 10−2
h1 (mg/g/min)	1.785 × 10−4	1.717 × 10−2	2.22 × 10−3	1.367 × 10−2	1.822 × 10−2
R2	0.1029	0.5549	0.0147	0.7275	0.2127
SSE	24.7487	486.952	1722.292	3429.027	6430.179
χ2	2231.626	228.498	744.0668	1096.902	4065.617
∆q	24.94439	22.79828	23.67928	23.73302	24.51645
Pseudo Second-order
qe, exp (mg/g)	4.9859	24.1981	43.8152	61.684	81.77
qe, cal (mg/g)	5.005	24.6305	42.5532	61.728	83.333
k2(g/mg/min)	1.3441	0.02813	3.7301	3.8572	2
h2 (mg/g/min)	33.67	17.0648	158.73	238.095	166.667
R2	1	0.9999	0.9999	1	0.9999
SSE	3.648 × 10−4	1.869 × 10−1	1.5926	1.936 × 10−3	2.4429
χ2	7.288 × 10−5	7.591 × 10−3	3.743 × 10−2	3.136 × 10−5	2.932 × 10−2
∆q	0.09577	0.44673	0.72007	0.01783	0.47786