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Capacitive deionization (CDI) technology holds great potential for rapid and efficient uranyl ion removal from wastewater. However, the related electrode materials still have much room for research. Herein, chitosan/phytic acid complexes were anchored on polypyrrole nanotubes (CS/PA-PPy) to fabricate the electrode for the electrosorption of uranyl ions (UO 2 2+). In this system, polypyrrole nanotubes provided specific channels for ion and electron diffusion, and chitosan/phytic acid complexes offered selective sites for UO 2 2+ binding. The results demonstrated that CS/PA-PPy via electrosorption showed faster kinetics and higher uranium uptake than those via physicochemical adsorption. The maximum adsorption capacity toward UO 2 2+ via electrosorption (1.2 V) could reach 799.3 mg g−1, which was higher than most of the reported CDI electrodes. Electrochemical measurements and experimental characterizations showed that the electrosorption of UO 2 2+ by CS/PA-PPy was a synergistic effect of capacitive process and physicochemical adsorption, in which the capacitive mechanism involved the formation of an electric double layer from hollow polypyrrole nanotubes, whereas the coordination of phosphate, amino and hydroxyl groups with UO 2 2+ was attributed to physicochemical adsorption. With the rational design of material, along with its excellent uranium removal performance, this work exhibited a novel and potential composite electrode for uranium capture via CDI from wastewater. Chitosan/phytic acid complexes were anchored on polypyrrole nanotubes to fabricate capacitive deionization electrode for the removal of uranyl ions from wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

Combining adsorption with other technologies holds great potential in fast and deep arsenic ion removal. Herein, chitosan‑zirconium composite adsorptive membranes (CS-Zr CM) were successfully prepared using simple casting and sodium hydroxide coagulation strategies, which was demonstrated the use in arsenic ion-capture electrodialysis based on their good adsorption performance. In the batch adsorption tests, the maximum adsorption capacities of CS-Zr CM for As(III) and As(V) were 134.2 mg/g and 119.5 mg/g, respectively. CS-Zr CM also exhibited satisfying adsorption selectivity and good reusability toward As(III) and As(V). However, the adsorption kinetics showed that they needed 48 h to reach the adsorption equilibrium and the adsorption ability toward trace arsenic ion was ineffective. Furthermore, CS-Zr CM was applied as the adsorptive membrane in the electrodialysis process. Under the influence of electric field, the As(III) and As(V) removal equilibrium time was shortened to 12 h and the concentrations of As(III) and As(V) ions could be efficiently reduced to below the WHO limit in drinking water (10 μg/L), which far surpassed the physicochemical adsorption method. Such good arsenic ion removal ability of CS-Zr CM together with the ease scalable fabrication, low cost, and biodegradable properties shows its huge prospects in arsenic-containing wastewater treatment. Biodegradable chitosan‑zirconium composite adsorptive membrane was used in the arsenic ion-capture electrodialysis configuration which exhibited fast and deep arsenic ion (As(III) and As(V)) removal. [Display omitted] [ABSTRACT FROM AUTHOR]