Removal of Methylene Blue from Aqueous Solutions by Using Nance (Byrsonima crassifolia) Seeds and Peels as Natural Biosorbents

Table 2

Constants for Langmuir and Freundlich isotherms corresponding to nance seeds and peels at pH 7 and 10.

Langmuir						Freundlich
Biosorbent	(mg/g)	(L/mg) ×10^−3			(kJ/mol)	((mg/g) (L/mg)^1/n)	n
Seeds (pH 7)	2553.80	1.92	0.95	0.9998	−1.5	0.52	1.017	0.9994
Seeds (pH 10)	7861.97	0.61	0.98	0.9998	−1.2	0.42	0.970	0.9994
Peels (pH 7)	2738.09	1.80	0.95	0.9999	−1.5	0.54	1.026	0.9997
Peels (pH 10)	1236.04	3.95	0.91	0.9929	−1.7	0.28	0.906	0.9990

: maximum capacity of adsorption (mg/g); : affinity constant (L/mg); : correlation coefficient; PRESS: predicted residual error sum of squares.