Hydrous iron oxide for removal of inorganic contaminants in simulated stormwater: A batch sorption kinetics study

Abstract

Urban stormwater runoff, which consists of inorganic and organic contaminants, is a major source of pollutants to receiving waters and therefore they need to be removed. Simultaneous removal of contaminants, Cd 2+ , Cu 2+ , Ni 2+ , Zn 2+ (heavy metal cations), and SeO 4 2− (oxyanion) from a simulated stormwater by a hydrous ferric oxide (HFO) was studied in batch and column sorption experiments. In the batch experiment the rate of sorption of the ions was rapid at the beginning and reached equilibrium in approximately 300 min. The amounts of ions sorbed were proportionate to the respective initial concentration of the ions added to the HFO. Cluster analysis showed that all heavy metals had similar sorption behavior, whereas Se had a distinctly different sorption process. Of the three different kinetic models tested the pseudo-first order kinetic model fitted the data the best. The column experimental results beyond 180 min were consistent with those of the batch experiment that the removal efficiencies of the ions were in proportion to the ion concentration in the feed. Below 180 min, Cu appeared to be preferentially removed than Zn.

Self-assembled targeting of cancer cells by iron(iii)-doped, silica nanoparticles

“…Iron oxide nanoparticles used for MRI imaging have also been observed to undergo enhanced cellular uptake, [84][85][86][87][88][89] and a similar TfR mediated mechanism may be operative. It has also been observed that toxic heavy metals in aquatic environments adsorb to hydrated ferric oxide, 90,91 and this behavior is viewed as a potential method for removing toxic metals from the environment. [92][93][94][95][96][97][98] In the context of surface iron(III) providing a mechanism for endocytosis, the TfR mediated uptake of ferric oxide nanoparticles may need to be considered in assessing the bioavailability of heavy metals adsorbed on such iron oxide particles.…”