Waste Material Adsorbents for Zinc Removal from Wastewater: A Comprehensive Review

Table 3

Adsorption capacities of different adsorbents for the removal of Zn²⁺ from water.

Adsorbent	Zn^+2 mg/L	Modifying agent(s)	𝑄max mg/g	Source
Bagasse	200	Sulfuric acid	31.11	[19]
Moss	100	Distilled water	14.7	[20]
Bentonite	300	—	52.91	[95]
Botrytis cinerea	100	NaOH	12.98	[23]
Sea nodule residue	200	Hydrochloric acid	32.46	[24]
Powdered waste sludge	200	H2O2	168	[25]
Waste activated sludge	16	—	36.9	[26]
Sugar beet pulp	160	Deionized water	17.78	[27]
Papaya wood	Deionized water	13.64	[31]
Clarified sludge	25	Distilled water	15.53	[32]
Rice husk ash		Distilled water	14.30
Neem bark		Distilled water	13.29
Activated alumina		—	13.69
Saltbush leaves	—	HCl	32.7	[33]
Natural zeolite	120	—	2.21	[45]
Black gram husk	10	Distilled water	33.81	[47]
Carrot residues	500	HCl	29.61	[52]
Cassava waste	—	Untreated	55.82	[54]
		Thioglycollic acid + HNO3	559.74
Caulerpa lentillifera	10	Tab water	2.66	[56]
Dried marine green macroalga	260	CaCl2	128.8	[57]
Sawdust-oak	—	Unmodified	7.1	[58]
Sawdust-oak	—	Formaldehyde	6.1
Sawdust-oak	—	Formaldehyde + NaOH	9.3
Sawdust-oak	—	NaOH	8.3
Sawdust-black locust	—	Unmodified	5.2
Sawdust-black locust	—	Formaldehyde	5.3
Sawdust-black locust	—	Formaldehyde + NaOH	9
Sawdust-black locust	—	NaOH	6.7
Sawdust-poplar	196	Unmodified	1	[59]
Sawdust-fir	196	Unmodified	1
Sawdust-poplar	130	NaOH	15.8
Sawdust-fir	40	NaOH	13.4
Lignin	6.5	HCl + ether + benzene	73.2	[60]
Bagasse fly ash	50	Hydrogen peroxide	2.34	[72]
Bagasse	850	Activated carbon (10°C)	24.06	[19]
	800	Activated carbon (25°C)	31.11
	775	Activated carbon (40°C)	54
Coal fly ash		Unmodified (30–60°C)	6.5–13.3	[96]
Fe impregnated fly ash		Fe(Cl)3 (30–60°C)	7.5–15.5
Al impregnated fly ash		Al(NO3)3 (30–60°C)	7.0–15.4
Rice husk ash + coal fly ash + palm oil fuel ash	15	Sol gel method	16.95	[97]