Removal of Hexavalent Chromium by Using Sustainable Green Materials as Low-Cost Adsorbents

Table 7

Parameters of different isotherms at 298 K.

	Green tea residue	Pu-erh residue	Tieguanyin residue
Langmuir
(mg g^-1)	6.15	19.50	12.31
(L mg^-1)	0.29	0.18	0.14
	0.07-0.41	0.10-0.53	0.13-0.6
	0.8954	0.9949	0.9260
Freundlich
(mg g^-1 (mg L^-1)^-1/)	1.67	3.54	2.04
	2.48	2.06	1.94
	0.9903	0.9830	0.9872
Temkin-Pyzhev
(kJ mol^-1)	3.01	0.81	1.49
(L g^-1)	16.06	5.66	5.76
	0.8976	0.9530	0.8797
Dubinin-Radushkevich
(kJ mol^-1)	1.36	1.13	1.54
(mg g^-1)	4.04	14.09	7.06
	0.7271	0.9378	0.7246