Adsorption of Ni2+, Hg2+, Pb2+, Cr3+, and Co2+ on iron oxide nanoparticles immobilized on cellulose fiber: equilibrium, kinetic, thermodynamic, mechanisms, and statistical supposition

Metallic nanoparticles (NPs) are of immense significance due to supra properties especially for contaminant remediation from water. However, NPs release in ecosystem is also threatening. To overcome this prospect, iron oxide (Fe2O3) NPs were composited with cellulose fibers (FeCt) by simple co-precipitation method, and used for removal of mercury, chromium, cobalt, lead, and nickel ions from synthetic-wastewater. The batch experiments determined that adsorption kinetics follow Langmuir isotherm model and best fit in pseudo-second-order reaction. FeCt composite material exhibited enhanced metal adsorption capacity as compared with cellulose polymer. The competitive capacity of all five heavy metals onto the adsorbents followed the adsorption order as Ni2+ > Hg2+ > Pb2+ > Cr3+ > Co2+ that is also related to the nature and strength of electrostatic interaction among metal ions. The statistical inference (Hotelling's t(2) statistics and t test) supports adsorption kinetics. The synthesized NPs composite material can be efficiently used for treatment of wastewater in domestic and industrial water filtration plants.