Engineered Magnetic Carbon-Based Adsorbents for the Removal of Water Priority Pollutants: An Overview

Table 3

Removal of heavy metals from aqueous solution using magnetic carbon-based adsorbents: preparation, removal operating conditions, and adsorption properties.

Synthesis route	Magnetic source	Carbon source	Adsorbate	Adsorption capacity (mg/g)	pH	T (°C)	Magnetization (emu/g)	BET area (m^2/g)	Reference
Magnetic CNTs by in situ coprecipitation modification	γ-Fe2O3	Commercial CNTs	Cr^6+	11.256	3	25	43.29	119.09	[223]
Magnetic BC by impregnation and direct pyrolysis	γ-Fe2O3	Peanut hulls	Cr^6+	77.54	5	25	36.79	145.25	[140]
Magnetic GO by hummers method and impregnation in situ hydrothermal synthesis	Fe3O4	Graphite	Cr^6+	31.8	7	25	12	182	[224]
Amino functionalized magnetic GO by hummer method and impregnation in situ hydrothermal synthesis	Fe3O4	Graphite	Cr^6+	123.4	2	25	30.2	57.55	[225]
Nitrogen doped magnetic AC by impregnation and direct pyrolysis processes using glucose as nitrogen source	Fe3O4 and Fe3C	Glucose and melamine	Cr^6+	29.46	7	25	130.7	56.2	[226]
Carboxyl functionalized magnetic CNTs by solvothermal method	Fe3O4	Commercial CNTs	Cr^6+	22.22	2	25	70.62	--	[227]
Chitin-magnetic CNTs by simple milling	Fe3O4	Commercial CNTs	Cr^6+	10.7	2	25	5.775	69.1	[228]
Dithiocarbamate functionalized magnetic RGO by hummer method, reduction with hydrobromic acid, and magnetic impregnation by coprecipitation.	Fe3O4	Graphite	Cu^2+; Cd^2+; Pb^2+; Hg^2+	113.64; 116.28; 147.06; 181.82	5; 6; 6; 6	25	--	194.8	[141]
Magnetic fluorine and nitrogen codoped carbon	Fe3O4	Melamine and polyvinylidene fluoride	Cr^6+	740.7	1		53.41	82.7	[229]
Magnetic AC high temperature carbonization and activation	Fe^0, Fe3O4, and Fe3C	Activated sludge	Cr^6+	203	3	25	7.6	114.24	[230]
Magnetic BC by iron salts impregnation and hydrothermal pyrolysis	γ-Fe2O3	Pinewood sawdust	Hg^2+	167.2	7	25	15.58	43.29	[142]
One step hydrothermal method with iron salt and hexamethylenediamine	γ-Fe2O3	Peanut hull	Cr^6+	142.86	--	25	--	62.4	[64]
Magnetic AC by low temperature carbonization, impregnation, and high temperature for magnetic modification and activation	Fe3O4	Termite feces	Cr^6+	66	3	25	1.46	699	[231]
1,4-Butane sultone modified magnetic AC by carbonization, activation, and finally magnetic impregnation with magnetic phase coprecipitated	Fe3O4	Pistachio shell	Pb^2+; Cd^2+	147.05; 119.04	5.5	25	11.6	--	[143]
Magnetic BC by pyrolysis and impregnation with coprecipitation of magnetic phase	Fe3O4	Banana peels	Zn^2+; Cu^2+; Hg^2+	72.8; 75.9; 83.4	6	25	39.55	323.2	[232]
Magnetic GO by graphite exfoliation and coprecipitation and magnetic RGO reduced by hydrazine hydrate	Fe3O4	Graphite	Cd^2+	2-12	234	25	34	148.2	[44]
Impregnation with humic acid, solvothermal process, and calcination	Fe3O4	Layered double hydroxides	Cu^2+; Cd^2+; Pb^2+	400.0; 375.0; 200.0	6	25	--	132.4	[233]
Magnetic BC modified with MnO by pyrolysis and impregnation with magnetic phase	Fe3O4	Palm kernel cake residue	Cd^2+; Cr^3+; Hg^2+; Pb^2+	18.60; 19.92; 49.64; 13.69	7	25	20.94	89.38	[144]
Direct pyrolysis and sonochemical method	Fe3O4	Biogas residue	Cu^2+; Pb^2+	75.76 181.82	5	--	39.96	79.64	[234]
Pyrolysis at 600 °C and physical comixing	Fe3O4	Wheat stalk and rice husk	Pb^2+	73.34 - 179.5	5	25	26.1 - 28.6	13.96 - 224.6	[235]
Pyrolysis at 500 °C, impregnation with iron salt	γ-Fe2O3	Blooms of alga Enteromorpha	Cr^6+	11.13	2	25	39.29	--	[236]

Adsorbent nomenclature: activated carbon (AC), biochar (BC), carbon nanocages (CNCs), carbon nanotubes (CNTs), graphene oxide (GO), multiwalled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), and reduced graphene oxide (RGO).