Ultrahigh Adsorption Capacity Zirconium-Magnesium Composite Oxide Nanoclusters Remove Malachite Green from Aqueous Media

The environmental pollution caused by organic dyes has damaged serious harm to human life. Hence, a series of Zr-Mg composite oxide nanoclusters with different metal ratios were synthesized by solvothermal method for adsorption of malachite green in aqueous solution. The optimal adsorbent with Zr/Mg metal molar ratio of 1 : 2 presented good adsorption performance, which adsorption capacity reached 12647.60 mg/g, and removal rate of malachite green reached more than 99%. These adsorbents were characterized by X-ray diffraction, Fourier-transform infrared spectra, nitrogen adsorption-desorption, scanning electron microscope, transmission electron microscope, and other methods. Influence of initial concentration of malachite green solution, pH, adsorption temperature, and contact time on absorption efficiency was investigated through batch experiments. Pseudo-second-order kinetic model can well describe the adsorption kinetic data. The three-parameter Sips isotherm model was more suitable for predicting the experimental results than Langmuir and Freundlich, and the adsorption process was endothermic.

High-Efficient Anionic Dyes Removal from Water by Cationic Polymer Brush Functionalized Magnetic Mesoporous Silica Nanoparticles

High efficiency removal of methyl orange (MO) and bromothymol blue (BT) dyes from contaminated water has been reported using magnetic mesoporous nanoparticles modified with cationic polymer brush (poly(2-methacryloyloxy)ethyl] trimethylammonium chloride solution) (Fe3O4-MSNs-PMETAC). Atom transfer radical polymerization (ATRP) was utilized to grow the polymer chains on the magnetic mesoporous silica nanoparticles. The chemical surface modifications were confirmed using IR, TGA, SEM and TEM. The results show that the obtained Fe3O4-MSNs-PMETAC materials were nearly spherical in shape with approximately 30 nm magnetic core, and silica shell thicknesses ranged from 135 to 250 nm. The adsorption performance of the material was found to be unaffected by the pH (3-9) of the media, with a removal efficiency of 100% for both dyes. The adsorption of BT and MO on the surface of Fe3O4-MSNs-PMETAC was found to follow Freundlich and Langmuir models, respectively. Since the synthesized nanocomposite materials exhibit an enhanced properties such as large maximum adsorption capacity, rapid synthesis process, and easy separation from solution, it could be an effective sorbent for the removal of other pollutants such as potentially toxic anionic elements (e.g., arsenate and chromate ions) from water and wastewater.