Table 3.

Kinetic parameters for Pb(II) removal by PAC@Fe₃O₄ at 323, 313, and 303 K, obtained through non-linear regression analysis.

Model	Parameters	Pb(II)
Pseudo-First-Order		323 K	313 K	303 K
	qe (exp) (mg g−1)	61.34	58.34	54.22
	qe (cal) (mg g−1)	59.69	56.64	52.74
	k1 (min−1)	0.44	0.41	0.38
	R 2	0.43	0.46	0.56
	χ 2	5.75	6.30	4.67
Pseudo-Second-Order	qe (exp) (mg g−1)	61.34	58.34	54.22
	qe (cal) (mg g−1)	60.80	57.85	53.89
	k2 (g mg−1 min−1)	0.02	0.02	0.02
	R 2	0.79	0.82	0.89
	χ 2	2.04	2.06	1.17
Intra-particle Diffusion	Kid	0.51	0.53	0.53
	C	53.96	50.47	46.85
	R 2	0.78	0.76	0.73
	χ 2	1.09	1.21	1.23