Table 5.

Maximum adsorption capacity of metal ions by different material the natural and synthetic origin.

Adsorbent material	$q_e$ (mg/g)	t (min)	References
Alternanthera philoxero	257.1 ($P{b}^{2+}$)	180	Yang et al.50
Miscanthus	13.2 ($C{d}^{2+}$)	60	Kim et al.51
Sugar cane bagasse	135.5 ($P{b}^{2+}$)	90	Inyang et al.52
Dairy-Manure	140.9 ($P{b}^{2+}$)	240	Cao et al.53
Hickory wooda	28.12 ($C{d}^{2+}$)	60	Wang et al.54
Pig manure	230.7 ($C{d}^{2+}$)	10	Kołodyńska et al.55
Cow manure	118.4 ($C{d}^{2+}$)	10	Kołodyńska et al.55
Biochar (CS0)	289.3 ($P{b}^{2+}$)	15	Chen et al.56
Biochar (CS0)	171.9 ($C{d}^{2+}$)	15	Chen et al.56
graphene sand composite	28.59 ($C{r}^{2+}$)	90	Dubey et al.57
Lignocellulose/Montmorillonite Nanocomposite	94.8 ($N{i}^{2+}$)	40	Wang et al.58
Palygorskite	8.8 ($C{o}^{2+}$)	180	Yuanming et al.59
xanthate-modified magnetic chitosan	76.9 ($P{b}^{2+}$)	120	Jianlong et al.60
xanthate-modified magnetic chitosan	34.5 ($C{u}^{2+}$)	80	Jianlong et al.60
xanthate-modified magnetic chitosan	20.8 ($Z{n}^{2+}$)	110	Jianlong et al.60
Paenibacillus polymyxa bacteria	1.602 ($C{u}^{2+}$)	120	Ravikumar et al.61
$A{l}_2{O}_3$	41.2 ($P{b}^{2+}$)	60–90	Mahdavi et al.62