Biogenic Synthesis of Magnetite Nanoparticles Using Leaf Extract of Thymus schimperi and Their Application for Monocomponent Removal of Chromium and Mercury Ions from Aqueous Solution

Table 4

Maximum sorption efficiencies (%R) and sorption capacities () of magnetite iron oxide nanoparticles and related adsorption parameters for removal of Cr(VI) and Hg(II) ions from wastewater.

S.no	Adsorbate	Adsorbent material	Maximum adsorption capacity (, mg/g)	Removal efficiency (%R)	pH of solution	Temperature (°C)	Adsorption kinetics	Adsorption isotherm	References
1	Hg(II)	Fe3O4 NPs	NA	87	5.5	25	PSO	Freundlich	[59]
2	Hg(II)	Fe3O4 NPs	NA	43.74	6	25	PSO	Langmuir	[59]
3	Cr(VI)	Fe3O4 NPs	105.26	82	5.2	25	PSO	Langmuir	[61]
4	Cr(VI)	Fe3O4 NPs	NA	72.45		25	PSO	Freundlich	[62]
5	Cr(VI)	Fe3O4 NPs	NA	98.95	2	25	PSO	Langmuir	[63]
6	Cr(VI)	Fe3O4 NPs	26.5	NA	2	25	PSO	Freundlich	[64]
7	Cr(VI)	Fe3O4 NPs	15	NA	1	25	PFO	Langmuir	[52]
8	Hg(II)	Schiff base decorated PAMAM dendrimer/Fe3O4 composites	605.78	NA	6	25	PSO	Langmuir	[13]
9	Hg(II)	Sulfur-functionalized PAMAM dendrimer/Fe3O4 composites	160.47	NA	6	25	PSO	Langmuir	[14]
10	Cr(VI)	Fe3O4 NPs	8.67	NA	4	25	PSO	Langmuir	[65]
11	Hg(II)	Fe3O4 NPs; Fe3O4 NPs	63.33	95	7	27	PSO	Langmuir	This study
	Cr(VI)		56.61	86	5	27	PSO	Freundlich

N.B: PFO = pseudo first order; PSO = pseudo second order; PAMAM = polyamidoamine; NA = not available.