An Experimental Study on the Adsorption and Desorption of Cu(II) in Silty Clay

Table 4

Adsorption isotherm model parameters and coefficient of determination () for adsorption of Cu(II) at different conditions.

Parameters	Langmuir isotherm			Freundlich isotherm			Temkin isotherm			Henry isotherm
	(L kg^−1)	(mg kg^−1)		(mg kg^−1)						(L kg^−1)	(mg kg^−1)
pH
2.0	0.0124	1698.06	0.992	68.0	1.763	0.988	185.30	−67.99	0.825	7.79	75.9	0.909
3.0	0.0201	1747.64	0.997	91.6	1.831	0.989	169.05	132.49	0.776	9.61	128.3	0.888
4.0	0.0522	2027.98	0.968	262.3	2.411	0.997	188.73	503.40	0.838	16.14	228.8	0.840
5.5	0.0524	2286.39	0.971	304.4	2.440	0.990	217.60	−192.11	0.869	18.99	250.4	0.820
Native soil	0.0524	2286.39	0.971	304.4	2.440	0.990	217.60	565.60	0.869	18.99	250.4	0.820
Reduce organic matter	0.0187	2129.93	0.976	99.82	1.597	0.932	323.58	−83.01	0.800	16.81	132.7	0.840
(°C)
10	0.0651	2053.32	0.972	311.3	2.269	0.993	196.88	561.95	2.569	16.95	254.9	0.798
25	0.0524	2286.39	0.971	304.4	2.447	0.990	217.60	565.60	0.869	18.99	250.4	0.820
35	0.2386	2840.71	0.958	417.8	2.905	0.965	234.58	639.45	0.928	18.48	302.6	0.743
Solution composition
Single-metal solution	0.0524	2286.39	0.971	304.4	2.440	0.990	217.60	565.60	0.869	18.99	250.4	0.820
Binary-metal solution	0.0323	1882.17	0.971	191.8	2.300	0.982	167.17	372.10	0.774	11.52	243.3	0.827