Utilization of Macadamia Nutshell Residue for the Synthesis of Magnetic Activated Carbon toward Zinc (II) Ion Removal

Table 2

Comparison of adsorption conditions and adsorption efficiency of various materials for Zn²⁺ removal.

Materials	pH	Adsorbent dosage (g L^−1)	Contact time (min)	Initial concentration of Zn^2+ (ppm)	Adsorption capacity (mg g^−1)	Re (%)	Pseudo-second-order parameters		Ref.
							qe,cal (mg g^−1)	k2 (g mg^−1 min^−1)
Zeolites	—	5	180	200	36.76	—	34.72	0.002	[41]
Fish bone	5.0	18	720	20	—	98	1.93	0.00023	[42]
Palm oil mill effluent-based AC	5.5	4	50	350	59.88	—	29.50	0.0020	[43]
Tire-derived AC	—	4	360	500	71.9	—	50.25	0.0057	[35]
Commercial AC	—	50	1440	500	14.0	—	5.57	0.0019	[35]
AC/Fe3O4	4.0	6	180	10	—	70.5	—	—	[44]
AC/Fe3O4	4.0–5.0	1.4	60	25	—	90	22.73	0.0081	This study

calculated from the published papers.