Novel diaminoguanidine functionalized cellulose: synthesis, characterization, adsorption characteristics and application for ICP-AES determination of copper(II), mercury(II), lead(II) and cadmium(II) from aqueous solutions

Table 4 Langmuir and Freundlich constants for metal adsorption by DiGu-MC

Langmuir isotherm model	K_L(L/g)	q_m(mg/g)	R²	R_L
Adsorbates
Cu²⁺	0.323	101.01	0.9968	0.0122–0.0583
Hg²⁺	0.371	73.50	0.9965	0.0107–0.0512
Pb²⁺	0.497	112.36	0.9981	0.008–0.0387
Cd²⁺	0.067	64.52	0.9904	0.0563–0.2299

Freundlich isotherm model	K_F	n	R²
Adsorbates
Cu²⁺	81.48	35.84	0.8461
Hg²⁺	63.94	48.78	0.8606
Pb²⁺	91.49	33.33	0.8443
Cd²⁺	27.26	6.73	0.8167

ISSN: 2661-801X