Removal of Cesium and Strontium From Radioactive Wastewater by Prussian Blue Nanorods

In this work, novel Prussian blue tetragonal nanorods were prepared by template-free solvothermal methods for removal of radionuclide Cs and Sr. It was worth that Prussian blue nanorods exhibited the better adsorption performance than co-precipitation PB or Prussian blue analogue composites. Thermodynamic analysis implied that adsorption process was spontaneous and endothermic which was described well with Langmuir isotherm and pseudo-second-order equation, the maximum adsorption capacity of PB nanorod was estimated to be 194.26 mg g-1 and 256.62 mg g-1 for Cs+ and Sr2+. The adsorption mechanism of Cs+ and Sr2+ was studied by X-ray photoelectron spectroscopy, X-ray diffraction and 57Fe Mössbaure spectroscopy, the results revealed that Cs+ entered in PB crystal to generate a new phase, the most of Sr2+ was trapped in internal crystal and the other exchanged Fe2+. Furthermore, the effect of co-existing ions and pH for PB adsorption process were also investigated. The results suggest that PB nanorods were outstanding candidate for removal of Cs+ and Sr2+ from radioactive wastewater.

Membrane Distillation for Wastewater Treatment: A Mini Review

Water serves as an indispensable part of human life and production. On account of the overexploitation of traditional water sources, the demand for wastewater recycling is expanding rapidly. As a promising water treatment process, membrane distillation (MD) has been utilized in various wastewater treatments, such as desalination brine, textile wastewater, radioactive wastewater, and oily wastewater. This review summarized the investigation work applying MD in wastewater treatment, and the performance was comprehensively introduced. Moreover, the obstructions of industrialization, such as membrane fouling, membrane wetting, and high energy consumption, were discussed with the practical investigation. To cope with these problems, various strategies have been adopted to enhance MD performance, including coupling membrane processes and developing membranes with specific surface characteristics. In addition, the significance of nutrient recovery and waste heat utilization was indicated.

DOPO-Modified Cellulose Microsphere: Preparation and Application for Selective Adsorption U(VI) under Acidic Solutions

Effective radioactive wastewater disposal is of great significance to the wide use of nuclear energy. In this work, 4, 4ˊ-[1, 4-phenyl-bis (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl) dimethyneimino)] diphenol (t-DOPO) was used to modify microcrystalline cellulose microsphere (t-DOPOR) to further enhance it affinity toward U(VI) through radiation method. The t-DOPOR were characterized for structural, morphological, and thermal properties by FTIR, SEM and TGA, which prove that t-DOPO is successfully modified on cellulose. Combination the advantage of cellulose and t-DOPO, t-DOPOR possessed abundant functional group (-OH, -NH and P=O), and exhibited extremely strong affinity toward U(VI) with a maximum adsorption capacity of 51.51 mg/g at pH 3. Particularly, A large distribution, KdU, up to 2.54×104 mL g−1 is found, implying extremely strong affinity toward U(VI) than Ln(III) (La(III), Eu(III), Dy(III), Yb(III)) at the binary system. Dynamic column experiment confirmed that t-DOPOR could separate selectively U(VI) in column experiment. In addition, even in the simulated groundwater trace amount of U(VI) was also eliminated efficiently by t-DOPOR. Lastly, the adsorption mechanism elaborated by XPS analysis was inner-sphere surface complexation between U(VI) and -OH, -NH and P=O groups of t-DOPOR. Overall, the synthesized t-DOPOR may be utilized as a promising adsorbent for separation and remediation of U(VI) from wastewater.