Table 1.

Summary of the isotherm adsorption parameters for AY220 removal by M1, M2, M3 and M4.

model		M1	M2	M3	M4
Langmuir	b (l m−1)	0.0034	(−)	0.0412	0.0004
			0.0019
	qm (mg g−1)	169.5	(−)	103.1	212.8
			312.5
	R2	0.8655	0.4353	0.9470	0.9902
Freundlich	Kf	1.02	0.33	8.70	0.12
	n	1.25	0.84	2.18	1.36
	R2	0.9648	0.9813	0.8094	0.9937