Table 4.

Adsorption isotherm parameters and correlation coefficients for the adsorption of Cu(II), Cd(II), Zn(II), Co(II) and Pb(II) on BC-CS 1-1.

Isotherm Models	Parameters	Cu(II)	Cd(II)	Zn(II)	Co(II)	Pb(II)
Langmuir ${\mathrm{q}}_{\mathrm{e}}=\frac{{\mathrm{q}}_0{\mathrm{K}}_{\mathrm{L}}{\mathrm{C}}_{\mathrm{e}}}{1+{\mathrm{K}}_{\mathrm{L}}{\mathrm{C}}_{\mathrm{e}}}$	qe,exp	45.76	48.56	44.10	24.42	68.36
	q0	52.35	96.63	48.91	27.38	65.13
	KL	0.024	0.004	0.020	0.007	0.050
	R2	0.944	0.978	0.966	0.963	0.948
Freundlich ${\mathrm{q}}_{\mathrm{e}}={\mathrm{K}}_{\mathrm{F}}{\mathrm{C}}_{\mathrm{e}}{}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$\mathrm{n}$}\right.}$	KF	5.37	0.97	5.34	1.45	9.37
	1/n	0.396	0.716	0.362	0.441	0.365
	R2	0.942	0.976	0.943	0.959	0.942
Temkin ${\mathrm{q}}_{\mathrm{e}}=\frac{\mathrm{R}\mathrm{T}}{{\mathrm{b}}_{\mathrm{T}}}\ln ({\mathrm{K}}_{\mathrm{T}}{\mathrm{C}}_{\mathrm{e}})$	KT	0.574	0.061	0.501	0.111	1.365
	bT	285.65	146.95	311.61	478.46	241.16
	R2	0.863	0.889	0.870	0.868	0.901
Dubinin–Raduszkiewicz $\ln {\mathrm{q}}_{\mathrm{e}}=\ln {\mathrm{q}}_{\mathrm{m}}-\mathsf{\beta }{\mathsf{\epsilon }}^2$ ${\mathrm{E}}_{\mathrm{a}}=\frac{1}{\sqrt{2\mathsf{\beta }}}$	qm	0.0015	0.0038	0.0012	0.0007	0.0020
	β	0.0041	0.0086	0.0038	0.0054	0.0036
	Ea	16.086	8.642	11.423	9.603	11.739
	R2	0.928	0.968	0.915	0.944	0.957