Adsorption isotherm parameters for the adsorption of Pb(ii) and Cd(ii) onto BC/FM in bi-solute system.

System	Langmuir			Freundlich			Sips (Langmuir–Freundlich)
	Q m (mg g−1)	K 1 (L mg−1)	R 2	n	K 2 (mg1−n g−1 L−n)	R 2	K LF	a LF	n LF	R 2
Pb (no Cd addition)	78.780	1.166	0.971	0.331	38.188	0.969	67.829	0.479	0.604	0.991
Pb + Cd (20 mg L−1)	80.096	0.769	0.993	0.382	30.598	0.896	68.621	0.934	1.197	0.997
Pb + Cd (100 mg L−1)	79.801	0.613	0.977	0.374	28.132	0.843	55.684	0.833	1.480	0.997
Cd (no Pb addition)	67.679	0.231	0.897	0.308	21.913	0.973	21.913	1.837	0.308	0.973
Cd + Pb (20 mg L−1)	42.628	2.562	0.973	0.214	21.527	0.930	64.577	1.631	0.676	0.985
Cd + Pb (100 mg L−1)	30.266	0.305	0.945	0.295	9.254	0.858	4.082	0.596	3.633	0.971