Batch Sorption Experiments: Langmuir and Freundlich Isotherm Studies for the Adsorption of Textile Metal Ions onto Teff Straw (Eragrostis tef) Agricultural Waste

Table 2

Isotherm parameters for adsorption of metal ions onto ATS.

Isotherm model	Metal ion	Estimated isotherm parameters
		𝑞max (mg/g)	𝑏 (L/mg)	𝑅^2
Langmuir	Ni	41.2	0.189	0.998
	Cu	34	0.173	0.982
	Cd	27.2	1.908	0.940
	Cr	21.3	0.143	0.962
	Pb	17.5	0.114	0.945
	Metal ion	𝑛	𝐾𝑓	𝑅^2
Freundlich	Ni	1.10	1.24	0.748
	Cd	2.11	3.52	0.977
	Cu	1.53	2.01	0.967
	Cr	1.50	1.77	0.939
	Pb	1.51	1.82	0.957