High-efficient mercury removal from environmental water samples using di-thio grafted on magnetic mesoporous silica nanoparticles

Abstract

In this work, magnetic di-thio functionalized mesoporous silica nanoparticles (DT-MCM-41) were prepared by grafting dithiocarbamate groups within the channels of magnetic mesoporous silica nanocomposites. The functionalized nanoparticles exhibited proper magnetic behavior. They were easily separated from the aqueous solution by applying an external magnetic field. The results indicated that the functionalized nanoparticles had a potential for high-efficient removal of Hg(2+) in environmental samples. The maximum adsorption capacity of the sorbent was 538.9 mg g(-1), and it took about 10 min to achieve the equilibrium adsorption. The resulted adsorption capacity was higher than similar works for adsorption of mercury. It can be due to the presence of di-thio and amine active groups in the structure of sorbent. The special properties of MCM-41 like large surface area and high porosity also provided a facile accessibility of the mercury ions into the ligand sites. The complete removal of mercury ions was attained with dithiocarbamate groups in a wide range of mercury concentrations. The recovery studies were also applied for the river water, seawater, and wastewater samples, and the values were over of 97 %.

Isotherm, kinetic, and thermodynamic studies on Hg(II) adsorption from aqueous solution by silica- multiwall carbon nanotubes

“…Various conventional adsorbents such as carbon materials, carbons derived from agricultural wastes and industrial wastes, biomaterials, and other materials have been investigated for the mercury removal (Yardim et al 2003;Labidi 2008;Anirudhan et al 2008;Sari and Tuzen, 2009;Mehdinia et al 2015;Vasudevan et al 2012;Wang et al 2014) but they are not highly efficient. Therefore, researchers are still making great efforts to identify new adsorbents with high capacities and efficacies.…”

DNA fragments assembled on polyamidoamine‐grafted core‐shell magnetic silica nanoparticles for removal of mercury(II) and methylmercury(I)

“…The Fe 3 O 4 –SiO 2 nanoparticle can adsorb cationic Hg(II) or MeHg(I) owing to the residual surface hydroxyl groups . However, grafting the nanoparticles with full‐generation PAMAMs gave rise to surface amine groups, which were positively charged in neutral solution and whose density increased with the dendrimer generation.…”

“…The Fe 3 O 4 -SiO 2 nanoparticle can adsorb cationic Hg(II) or MeHg(I) owing to the residual surface hydroxyl groups. 26 However, grafting the nanoparticles with full-generation PAMAMs gave rise to surface amine groups, which were positively charged in neutral solution and whose density increased with the dendrimer generation. The amine groups not only shielded the negatively charged hydroxyl groups on the surface of Fe 3 O 4 -SiO 2 , but impeded, via Coulombic repulsion, the adsorbates entering the polyamidoamine structures to coordinate with the interior tertiary nitrogen atoms.…”

Use of red mud (bauxite residue) for the retention of aqueous inorganic mercury(II)

“…They show that 85.5, 90.1 and 99.6 % of the complete process took place within the first minute of contact, where the removal percentages were 97.0, 99.3 and 99.6 % for the 0.5, 5 and 50 μM Hg(II) initial concentrations, respectively, evidencing that the sorption of Hg(II) on RM is an extremely fast process where Hg(II) exhibits a high affinity towards RM surfaces. In this aspect, RM is comparable to other highly efficient Hg(II) sorbents, as for instance active carbon (Huang and Blankenship 1984), modified magnetic Fe oxide nanoparticles (Parham et al 2012), magnetic di-thio functionalized mesoporous silica nanoparticles (Mehdinia et al 2015), Fe and binary Fe/Mn oxyhydroxides (Kokkinos et al 2014), or rice husk ash (Feng et al 2004).…”

“…peat (Viraraghavan and Kapoor 1995), chitosan and its derivatives (Miretzky and Fernandez Cirelli 2009) or inorganic: e.g. dispersed iron oxide, hydrous manganese and tin oxides , Fe oxyhydroxide (FeOOH) and Fe/Mn oxyhydroxides (Kokkinos et al 2014), zeolites (Chojnacki et al 2004), clays (Eloussaief et al 2013;Viraraghavan and Kapoor 1994), pozzolana and yellow tuff (Di Natale et al 2006) and synthetic titanosilicates (Otero et al 2009) or magnetic di-thio functionalized mesoporous silica nanoparticles (Mehdinia et al 2015). Also, a wide array of wastes have been proposed-either used directly or as precursors-as novel low-cost Hg adsorbents (Bhattacharyya et al 2013;Miretzky and Fernandez Cirelli 2009), and these include agricultural (e.g.…”