Adsorption of hexavalent chromium from aqueous solution by modified corn stalk: A fixed-bed column study

Uranium is important in the nuclear fuel cycle both as an energy source and as radioactive waste. It is of vital importance to recover uranium from nuclear waste solutions for further treatment and disposal. Herein we present the first chalcogenide example, (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS), in which organic amine cations can be used for selective UO22+ ion-exchange. The UO22+-exchange kinetics perfectly conforms to pseudo-second-order reaction, which is observed for the first time in a chalcogenide ion-exchanger. This reveals the chemical adsorption process and its ion-exchange mechanism. FJSM-SnS has excellent pH stability in both strongly acidic and basic environments (pH = 2.1–11), with a maximum uranium-exchange capacity of 338.43 mg/g. It can efficiently capture UO22+ ions in the presence of high concentrations of Na+, Ca2+, or HCO3– (the highest distribution coefficient Kd value reached 4.28 × 104 mL/g). The material is also very effective in removing of trace levels of U in the prese...

Efficient Removal and Recovery of Uranium by a Layered Organic-Inorganic Hybrid Thiostannate

Naturally occurring diatomaceous earth (diatomite) has been tested as a potential sorbent for Pb(II) ions. The intrinsic exchange properties were further improved by modification with manganese oxides. Modified adsorbent (referred to as Mn-diatomite) showed a higher tendency for adsorbing lead ions from solution at pH 4. The high performance exhibited by Mn-diatomite was attributed to increased surface area and higher negative surface charge after modification. Scanning electron microscope pictures revealed a birnessite structure of manganese oxides, which was featured by a plate-like-crystal structure. Diatomite filtration quality was improved after modification by manganese oxides. Good filtration qualities combined with high exchange capacity emphasised the potential use of Mn-diatomite in filtration systems.

19. Al-Degs Y., MAM Khraisheh, Tutunji, M.F, Sorption of lead ions on diatomite and manganese-oxides modified diatomite.

Removal of organic pollutants from aqueous solution using agricultural wastes: A review

The removal of dye from aqueous solution using alginate-halloysite nanotube beads.

Adsorption characteristics of methylene blue by peanut husk in batch and column modes

Continuous fixed-bed studies were undertaken to evaluate the performance of manganese oxide-coated sand (MOCS) as an adsorbent for the removal of uranium(VI) ions from aqueous solution under the effect of various process parameters such as the bed depth, the flow rate, the presence of salt and the initial U(VI) ion concentration. The U(VI) ion uptake by MOCS increased with initial U(VI) ion concentration and bed height, but decreased as the flow rate increased. A shorter breakthrough time was observed in the presence of salt. The experimental data obtained from the breakthrough curves were analyzed using the Thomas model. The BDST model was also applied to predict the service times for other flow rates and initial concentrations. The results showed that the Thomas model was suitable for the description of the whole breakthrough curve, while the data were in good agreement with the BDST model. The columns were regenerated by eluting the bound U(VI) ions with 0.5 mol/l HNO3 solution after the adsorption stu...

https://journals.sagepub.com/doi/pdf/10.1260/0263-6174.28.4.313

Jiyun Song

Papers

Adsorption characteristics of methylene blue by peanut husk in batch and column modes

Use of Manganese Oxide-Coated Sand for the Adsorption of Uranium(VI) Ions from Aqueous Solution Using a Column Mode