Table 2.

Langmuir, Freundlich and BET isotherm constants and correlation coefficients of Pb²⁺ binding capacity of carrageenans.

Constants	ι-carrageenan			κ-carrageenan			λ-carrageenan
	pH = 2	pH = 4	pH = 6	pH = 2	pH = 4	pH = 6	pH = 2	pH = 4	pH = 6
Langmuir model
b, (mL mg−1)	0.047	0.042	0.032	0.017	0.014	0.012	-	0.007	0.012
qmax, (mg g−1)	132.2	154.6	178.0	67.3	103.0	36.9	-	26.1	13.9
R2	0.9834	0.9912	0.9900	0.9814	0.9741	0.9803	-	0.4890	0.8895
Freundlich model
KF, (mg g−1)	3.12	3.97	3.03	2.34	1.95	1.12	-	0.65	1.65
n	4.48	4.27	3.01	3.78	2.31	2.85	-	1.57	4.62
R2	0.9204	0.9412	0.9509	0.9300	0.9549	0.9458	-	0.9310	0.9478
BET model
Q, (mg g−1)	45.9	38.7	32.6	12.5	43.8	12.9	-	0.43	0.65
B	1.76	1.65	1.38	3.82	1.76	5.34	-	0.54	0.64
R2	0.0961	0.1533	0.1294	0.5342	0.2323	0.1264	-	0.1876	0.1543