Amino modification of biochar for enhanced adsorption of copper ions from synthetic wastewater.

Applications of Zeolites in Sustainable Chemistry

Application of polymeric membranes for the adsorption of hazardous pollutants 
may lead to the development of next-generation reusable and portable water purification appliances. Membranes for membrane adsorption (MA) have the dual function of membrane filtration and adsorption to be very effective to remove trace amounts of pollutants such as cationic heavy metals, anionic phosphates and nitrates. In this review article, recent progresses in the development of MA membranes are surveyed. In addition, recent progresses in the development of advanced adsorbents such as nanoparticles are summarized, since they are potentially useful as fillers in the host membrane to enhance its performance. The future directions of R&D in this field are also shown in the conclusion section.

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Removal of heavy metals and pollutants by membrane adsorption techniques

Ring size dependent crown ether based mesoporous adsorbent for high cesium adsorption from wastewater

Uranium is the main element for nuclear energy production and is one of the most hazardous radionuclides; its effective enrichment plays a key role in energy strategy and environmental safety. Oxime-functionalized nanostructures are the most promising candidates for uranium adsorption. However, current methods for their preparation mainly focus on multistep grafting and oximation processes, and the nanostructures usually show low efficiency. Here, we report a rapid one-step process to synthesize salicylaldoxime/polydopamine modified reduced graphene oxide (RGO-PDA/oxime) via the polymerization of dopamine (DA) and simultaneous deposition of oxime with an obviously decreased total synthesis time of 2 h. The obtained maximum uranium adsorption capacity of up to 1049 mg g−1 was 3–16 times larger than those of the reported single PDA or oxime modified nanostructures. The RGO-PDA/oxime followed the pseudo-second-order kinetics model and Langmuir isotherm equation with much higher adsorption selectivity and recyclability. The outstanding sorption performance is attributed to the electrostatic repulsion between GO and salicylaldoxime and the effective combination between PDA and oxime molecules. Finally, given the adhesion capability of DA to diverse surfaces, this rapid one-step method was used to prepare five other oxime/PDA modified materials, which also showed improved uranium adsorption efficiency. These findings provide a way to obtain oxime-functionalized nanostructures with promising uranium adsorption efficiency.

Highly efficient uranium adsorption by salicylaldoxime/polydopamine graphene oxide nanocomposites

Effects of the different conditions of uranyl and hydrogen peroxide solutions on the behavior of the uranium peroxide precipitation

Novel application of nanozeolite for radioactive cesium removal from high-salt wastewater

Equilibrium, kinetic and thermodynamic study of cesium adsorption onto nanocrystalline mordenite from high-salt solution.

Selective ion-exchange with zeolites has been considered as one of the most promising means to remove a radioactive isotope of cesium, 137Cs, present in low concentration in seawater. However, there has been no report on the fundamental structure–property relation of zeolite-based Cs ion-exchangers. In this study, we investigate the origin of the selectivity of the radioactive cesium isotope in zeolite frameworks using zeolite A (LTA) as a model system. We prepared seven single crystals of fully dehydrated and partially cesium exchanged Zeolite A (LTA) with different Cs+/Na+ ratios. Their single-crystal synchrotron X-ray diffraction experiments revealed the significant differences in the degree of exchange and the site selectivity of Cs+ ions depending on the initial Cs+ concentrations in given ion exchange solutions. The degree of Cs+-ion exchange increases from 15.8 to 44.2% as the initial Cs+ concentration increases and the Na+ content decreases. In addition, it was found that Cs+ ions are energeticall...

Selective Removal of Radioactive Cesium from Nuclear Waste by Zeolites: On the Origin of Cesium Selectivity Revealed by Systematic Crystallographic Studies

Keun-Young Lee

Papers

Effects of the different conditions of uranyl and hydrogen peroxide solutions on the behavior of the uranium peroxide precipitation

Novel application of nanozeolite for radioactive cesium removal from high-salt wastewater

Equilibrium, kinetic and thermodynamic study of cesium adsorption onto nanocrystalline mordenite from high-salt solution.

Selective Removal of Radioactive Cesium from Nuclear Waste by Zeolites: On the Origin of Cesium Selectivity Revealed by Systematic Crystallographic Studies

Biosorption of radioactive cesium from contaminated water by microalgae Haematococcus pluvialis and Chlorella vulgaris.