Table 1.

ENMs synthetized for the remediation of marine environment.

ENM	Concentration	Properties	Target Contaminants	Mechanism	Media	Remediation Efficiency	Reference
Graphene oxide sponge enriched with florin groups (USTC-6@GO@sponge)	NF	carbon-based ENM with microporosity and great hydrophobicity for the selective adsorption of organic compounds	diesel oil, gasoline, soybean oil, light petroleum, n-hexane, bromobenzene, N’N-dimethylformamide (DMF), tetrahydrofuran, acetone, CCl4 methylbenzene	adsorption	seawater	NF	[68]
Chitosan-grafted carbon nanotubes (CTS-g-CNTs)	0.6 g L−1	external nanotube diameter of 30 nm and an inner diameter of 8.48 nm, stable in seawater	Cs	adsorption	seawater	NF	[69]
Graphene oxide functionalized with polyethyleneimine (GO-PEI)	10 mg L−1	foam with three dimensional porous structures	Hg	adsorption	seawater	NF	[70]
Manganese-ferrite NPs (MnFe2O4)	50 mg L−1	NP diameter of 75 ± 15 nm; magnetism	As, Pb	adsorption	seawater	NF	[71,72,73]
Alginate and polyvinyl alcohol (PVA)-alginate entrapped nanoscale zero-valent iron (nZVI)	1 g L−1 2 g L−1	Particles of powder average size 50 nm	Cu, Zn, Cr, As	adsorption	saline wastewater	Cu 84.2%; Cr 70.8%; Zn 31.2%; As 39.8%	[74]
nFe3O4/fly ash composite	0.5 g in 25 mL of triphenyltinchloride (TPT) solution	nFe3O4 size particles < 50 nm	TPT	adsorption	seawater	98.40%	[75]
Potasium copper hexacyanoferrate (KCuHCF)	0.1 g L−1	NPs size of 10–17 nm	Cs	adsorption	seawater	99%	[76]
Zeolitic imidazolate framework-8 functionalized with ferrocyanide (ZIF-8-FC)	V/m = 1000 mL g−1	cubic particles with a surface area of 589 m2 g−1	Cs	adsorption	seawater	60% at 3 h 85% at 24 h	[77]
Magnetic multilayer core–shell (Fe3O4@SiO2@KTiFC)	5 mg of Fe3O4@SiO2 @KTiFC particles added to 4 mL seawater	microspheres with a magnetite core of 300 nm; magnetism	Cs	adsorption	seawater	97.7%	[78]
Prussian blue-embedded magnetic hydrogel beads (PB-MHBs)	1 mg mL−1	average size of 33.8 mm; magnetism	Cs	adsorption	seawater	96.7%	[23]
Magnetic carbon microspheres (Fe3O4-CM)	5 g L−1	diameter microspheres of ~30 μm; superparamagnetis	polycyclic aromatic hydrocarbons (PAH)	degradation	marine sediments	87%	[79]
Nano-hydroxyapatite particles (nHAp)	0–10% nHAp/dry weight	rod structure with dimensions of 20 nm (i.d.) × 200 nm (length); surface area of 130 m2 g−1	Pb, Cd	sorption	marine sediments	NF	[80]
nZVI coated to polyacrylic acid (nanofer 25S)	low (2, 3 and 4%) and high (5, 10 and 20%) dosages	diameter of 50 nm; total iron content of 80–90 wt. %; surface area of 20–25 m2 g−1	Al, As, B, Ba, Co, Cu, Ni	adsorption, reduction	marine sediments slightly polluted by heavy metals	at 3 g: Co 100%; at 4 g: Al 33.3%, As 76%, Cu 96.8%, B 0%; at 5 g: Al 71.4%, Cu 100%, As 62%; At 10 g: B 60.4%; at 20 g: Co 54.3%	[81]
Nanoscale zero valent iron (nZVI)	0.01–1 g/L	particle sizes < 100 nm	polycyclic aromatic hydrocarbons (PAHs)	oxidation	PAHs contaminated sediments	70.2% at 0.01 g/L, 78.3% at 0.1 g/L, 86.3% at 0.5 g/L, 78.0% at 1 g/L	[55]
polyvinylpyrrolidone-coated magnetic ENM (PVP-Fe3O4 NMs)	167 mg/L	median size of 11.2 nm	Pb, Cr, Ni, Cd	adsorption	seawater	Pb 100%; Cr 98.8%; Ni 60–70%; Cd 40–50%	[82]
	375 ± 10 mg/L		oil-water mixtures			70% of lower-chain alkanes (C9–C22); 65% of higher-chain (C23–C26),	[83]
Starch-based nanosponges	12 mg in 15 mL	citrate nanosponges with β-cyclodextrin (β-CD) or ®linecaps (®LC) scaffold	Cu, Zn	adsorption	seawater	Cu 80–84% Zn < 60%	[84]
		pyromellitic nanosponges with β-cyclodextrin (β-CD) or ®linecaps (®LC) scaffold				Cu 36–45%; Zn <60%
Powder of Cellulose-Based Nanostructured Sponges (CNS)	0.8 mg mL−1	particle size range 50 to 400 μm	Zn, Cu, Cr, Cd	adsorption	seawater	90%	[45,85,86]
KCuHCF-cellulose hydrogel	10 mg in 20 mL	Cubic-shaped particles of 10–12 nm	Cs	adsorption	seawater	>90%	[87]
PB coating Fe3O4 NPs anchored to the surface of the GO sheets (PB/Fe3O4/GO)	0.05 g of NPs in 30 mL	average size of 17 nm;magnetism	Cs	adsorption	seawater	52.19%	[88]

NF: data not found.