Table 2. Isotherm Parameters of Langmuir, Freundlich, Sips, and Dubinin–Radushkevich Models for the Sorption of As(III) and As(V) onto the AMOX-Type Sorbents, at 22 °C.

	AMOX1		AMOX2		AMOX3
isotherm parameters	As(III)	As(V)	As(III)	As(V)	As(III)	As(V)
Langmuir Model:
qm, mmol g−1	4.3108	3.934	4.5454	4.3926	4.68	4.6376
KL, L mmol–1	1.852	0.7782	2.3527	0.9878	3.6455	1.4076
R2	0.9286	0.8571	0.9387	0.8953	0.9761	0.9155
χ2	0.14	0.21	0.14	0.2	0.06	0.2
Freundlich Model:
KF, mmol1–1/n·L1/n·g–1	2.2598	1.54	2.522	1.882	2.867	2.2357
1/n	0.302	0.3843	0.2871	0.363	0.2612	0.331
R2	0.7309	0.6919	0.7384	0.7195	0.8023	0.7311
χ2	0.53	0.46	0.6	0.53	0.5	0.6
Sips Model:
qm, mmol g–1	3.803	3.1287	4.068	3.6491	4.3835	3.98
aS	7.01	2.581	10.856	2.996	9.13	5.575
1/n	1.997	2.846	2.011	2.464	1.484	2.302
R2	0.9952	0.9879	0.9972	0.9971	0.9895	0.9947
χ2	0.01	0.02	0.006	0.01	0.027	0.02
Dubinin–Radushkevich Model:
qDR, mol g–1	0.00739	0.00767	0.00766	0.00734	0.00809	0.00826
β, mol2 J–2	4.015 × 10–9	3.734 × 10–9	3.250 × 10–9	5.432 × 10–9	5.034 × 10–9	4.458 × 10–9
E, kJ mol–1	11.16	11.57	12.4	9.59	9.97	10.59
R2	0.7937	0.8021	0.8653	0.7952	0.8173	0.8287
χ2	0.0001	0.0001	0.0001	0.0001	0.0001	0.0001