K₂CO₃-Activated Pomelo Peels as a High-Performance Adsorbent for Removal of Cu(II): Preparation, Characterization, and Adsorption Studies

Table 3

Parameters of kinetic models for Cu(II) adsorption onto PAC850-1-3.

C0 (mg/l)
Pseudo first-order model	qe,cal (mg/g)	k1 (1/min)	R^2	ARE (%)
100	62.88	0.0199	0.8742	41.3
200	32.63	0.0209	0.9791	73.2
300	36.49	0.0216	0.9369	73.8
Pseudo second-order model
	qe,cal (mg/g)	k2 (g/mg·min)	R^2	ARE (%)
100	111.11	0.000749	0.9985	3.7
200	123.46	0.00172	0.9999	1.5
300	140.85	0.00170	1.0000	1.3
Intraparticle diffusion model
	C (mg/g)	k3 (mg/g·min^1/2)	R^2	ARE (%)
100	63.74	2.90	0.9361	4.0
200	93.42	1.98	0.7993	3.6
300	107.12	2.27	0.7389	3.8