Table 1.

Empirical coefficients obtained from the Langmuir model fitting and K_d coefficients estimated at C_e = 1.2 mmol·L⁻¹ for the different ILs studied.

IL	[Na2SO4] (mol·kg−1)	qmax (mmol·g−1)	B (L·mmol−1)	R2	Kd (L·kg−1)
|C4C1im|CI	No salt	0.26	0.64	0.900	95
	0.28	0.47	4.52	0.999	332
	0.70	0.54	3.02	0.997	353
	1.06	0.58	5.76	0.997	422
	1.41	0.74	3.54	0.961	498
	1.76	0.78	3.31	0.993	522
|C4C1im||CH3SO3|	No salt	0.13	3.94	0.973	92
	0.28	0.72	0.13	0.924	80
	0.70	0.34	7.54	0.939	254
	1.06	0.60	2.94	0.969	388
	1.41	0.45	78.04	0.977	374
	1.76	0.53	39.79	0.899	433
|C4C1im||CF3SO3|	No salt	0.58	2.56	0.990	367
	0.28	0.67	1.12	0.988	318
	0.70	0.57	3.52	0.997	385
	1.06	0.81	2.96	0.999	525
	1.41	0.93	2.10	0.995	556
	1.76	1.02	3.17	0.978	670
|C4C1im||NTf2|	No salt	1.04	8.71	0.992	794
	0.28	0.93	5.91	0.981	680
	0.70	0.99	5.73	0.999	719
	1.06	1.04	4.57	0.933	734
	1.41	1.02	16.99	0.964	809
	1.76	1.13	20.86	0.988	908
|C4C1py||NTf2|	No salt	1.10	75.71	0.995	906
	0.28	1.20	8.41	0.997	909
	0.70	1.47	5.69	0.997	1068
	1.06	1.15	23.72	0.991	929
	1.41	1.32	61.70	0.989	1088
	1.76	1.41	406.48	0.458	1173