. 2022 Feb 24;12(5):769. doi: 10.3390/nano12050769

Table 1.

Summary of different nanoparticles-mediated removal of different pollutants from contaminated media.

Nanoparticles	Remediated Contaminant(s)	Operational Conditions and Removal Efficiency	References
Polyvinylpyrrolidone (PVP) coated iron oxide nanoparticles	Cd and Pb	NPs applications were integrated with the process of bioremediation mediated by Halomonas sp. In the removal setup of Cd and Pb, Halomonas sp. was inoculated for 48 h at 180 rpm, 28 °C. The 100% removal was recorded after 24 h, while for Cd, it was observed after 48 h.	[44]
Zero-valent iron (nZVI) commercial suspension at two doses (1% and 10%)	As	pH was set at 12.2 ± 0.1 of the nZVI suspension. To avoid the aggregation of nZVI in the suspension, polyacrylic acid was used as a stabilizer. Maximal immobilization of As in brownfield soil was recorded at 10% of nZVI.	[45]
Graphene oxide nanoparticles (nGOx) and nZVI	Metals, viz., Cd, Pb, Zn, Cu, and As in the As-Metals polluted soil	Applications of nZVI and nGOx to the polluted soils considerably impacted the availability of As and metals. Cu, Pb, and Cd were immobilized by nGOx, while mobilized As and P. In a turn of nZVI, it immobilized the effectively As and Pb, and poorly Cd but enhanced availability of Cu. This study revealed that both NPs applications might be act as strategies for the immobilization and stabilization that can later be utilized for phytoremediation.	[46]
Titanium oxide nanoparticles-bonded-chitosan nanolayer (NTiO₂-NCh)	Cd and Cu	The pH was set at 7.0 during the experimentation. The removal was assisted by 60–70 s heating by using microwave–enforced sorption approach. Application of NTiO₂-NCh was found to eliminate Cu and Cd by 88.01% and 70.67%, respectively.	[47]
Palladium (Pd), Pd NPs	Cr	The use Pd NPs as bionanocatalyst has been explored. It was found that Pd NPs completely reduced Cr⁶⁺ in 12 h. 6.3 mg of PdNPs was used to reduce 5.0 µmol of Cr⁶⁺.	[48]
Magnetic iron oxide nanoparticles (Fe₃O₄ NPs) treated with Staphylococcus aureus, and surface encapsulated with phthalic acid (n-Fe₃O₄-Phth-S aureus)	Cu, Ni, Pb	n-Fe₃O₄-Phth-S was found to remediate 83.0–89.5%, for Cu²⁺, 99.4–100%, for Pb²⁺, and 92.6–7.5% for Ni²⁺. The study also identified n-Fe₃O₄-Phth-S. aureus as an excellent biosorbent for the removal of divalent ions from an aqueous medium.	[49]
ZnO NPs	Cu, Cd, Cr, and Pb	The applications of ZnO-NPs at 5 mg L⁻¹ with Bacillus cereus and Lysinibacillus macroides showed the maximal removal of Cr, Cu, and Pb which was 60%, 70%, and 85%, respectively. The optimal pH for efficient removal was 8.0. The removal was less in the case of bacteria-mediated remediation which was found to be 83 and 70% in B. cereus and 60 and 65% in L. macroides.	[50]