Search

A silver-based material coated with polyaniline (Ag@PANI) was successfully synthesized to effectively remove I2 and I−. Experimental results showed the sorption capacity of I2 by Ag@PANI reached 132 wt.%, and the I− uptake capacity reached 419.6 mg·g−1. Additionally, Ag@PANI could effectively remove up to 99.9% of low I−-contaminated water, and the distribution coefficient (Kd) toward I− reaches 4.65 × 106 mL·g−1. Adsorption mechanism showed I2 and I− were immobilized on Ag@PANI by conversion to AgI. Moreover, electrostatic interactions might result in higher I− retention ability. Overall, Ag@PANI can be employed as promising adsorbent for the efficient removal of radioactive iodine. [ABSTRACT FROM AUTHOR]

The rapid detection of uranium in water environment is of great significance for water purification and uranium recovery. In this work, ultrathin nickel hydroxide (Ni(OH)2) nanosheets was in-situ growth on carbon nanotubes (CNTs) to form Ni(OH)2@CNTs electrode for uranyl ion (UO22+) detection. The as-prepared Ni(OH)2@CNTs shows good sensitivity in the electrolyte containing UO22+ with the limit of detection of about 8.603 ppb. Moreover, the Ni(OH)2@CNTs also exhibits significant selectivity for UO22+ in complex wastewater with several interfering cations and anions. This work provides a novel Ni(OH)2@CNTs electrode for UO22+ detection from uranium-containing water. [ABSTRACT FROM AUTHOR]

The Cu2O/Cu modified shungite (ShC) absorbent (Cu2O/Cu-ShC) was synthesized by hydrothermal method, benefiting from the mineral backbone and Cu2O/Cu particles, Cu2O/Cu-ShC can remove ~ 96% of I− within 60 min, the batch experiments showed that the I− adsorption process follows pseudo-second-order model and Langmuir model with maximum adsorption capacity of 10.99 mg/g. The high binding affinity between Cu+ and I− contributes effective removal of I− and excellent selectivity at high concentrations of competing ions. This work highlights the feasibility of Cu2O/Cu-ShC for the radioactive iodine separation, and provides a promising sorbent material for large-scale purification of radioactive iodine anions in wastewater. [ABSTRACT FROM AUTHOR]

The efficient removal of uranium from aqueous solutions is critical for ecological safety. Herein, a novel phytic acid and melamine covalent polymer adsorbent (named PEM) was designed and synthesized through a simple one-pot method, and its adsorption performance and mechanism of U(VI) were systematically investigated. The maximum adsorption capacity on U(VI) achieved 505.05 mg g−1 at pH 4.0, calculated with the Langmuir model, which was much higher than most other adsorbents under the same environment. Importantly, the reaction reached equilibrium quickly in the initial 20 min at 298 K. The sorption process conformed to a pseudo-second-order kinetics model and Langmuir model, indicating that the chemisorption of the monolayer was dominant. Overall, the synthesized PEM could be utilized as an easy, efficient, less time-consuming material for the removal of uranium from acidic nuclear wastewater. [ABSTRACT FROM AUTHOR]

In this work, a composite of phosphonate-functionalized MoS2 supported on carbon cloth, MoS2-IP6 NRA/CC, was prepared by the hydrothermal method to effectively remove U(VI). Results showed that the saturated adsorption capacity of MoS2-IP6 NRA/CC for uranium was 183.3 mg g−1. The adsorption process was in good agreement with Langmuir model and pseudo-second-order kinetics model. Besides, MoS2-IP6 NRA/CC showed good adsorption on uranyl ions under acidic conditions, and the material was recyclable, indicating that the material can be used as a potential radioactive nuclear processing material. [ABSTRACT FROM AUTHOR]

Uranium is important in the nuclear fuel cycle as both as an energy source and as radioactive waste. Herein, activated carbon (AC) prepared from waste cigarette filters by convenient carbonization and functionalization was chosen as the raw materials for radionuclides adsorption. Batch adsorption experiments showed that AC presented comparable UO22+ adsorption capacity (106 mg g−1) and very outstanding selectivity. The adsorption process accorded with Langmuir model and the pseudo-second-order kinetics model well. This work combines the waste cigarette filters with the radioactive nuclear treatment materials, which may provide a new strategy for the future treatment of waste cigarette butts. [ABSTRACT FROM AUTHOR]

Cotton carbon aerogel was prepared and used as a new water-insoluble adsorbent to remove strontium from aqueous solution. A comprehensive study on adsorption of strontium by cotton carbon aerogel was conducted regarding the effects of initial pH, temperature, initial strontium concentration, and contact time. The adsorbent was characterized by SEM. The results of regression analysis indicated that the adsorption process largely depends on the pH and temperature. The optimum pH range for adsorption process is 5-7. The maximum removal efficiency of strontium from aqueous solution was 60.16%. Moreover, cotton carbon aerogel adsorbent has good reusability before the fifth reuse. [ABSTRACT FROM AUTHOR]

The urease of carbonate-mineralization bacteria (bacillus) secretion is conducive to the formation of carbonate. At the presence of urea and Sr, carbonate-mineralization bacteria could lead to the rapid formation of strontium carbonate precipitation. The mineralization process and efficiency were observed by adding nano-montmorillonite (nano-MMT). The effect of bacillus and bacillus/nano-MMT on the mineralization efficiency of Sr was investigated by atomic spectrophotometer. The results showed that both the bacillus and nano-MMT played an important role in the nucleation, growth, and accumulation of strontium carbonate crystals. And this method can efficiently separate simulated radionuclide strontium from high-level radioactive waste. [ABSTRACT FROM AUTHOR]

A new sustainable filamentous fungi-based process is reported to synthesize mycelium/bayberry tannin (BT) hybrid materials. The hybrid materials are produced with fungi growing in solution, where the cell wall interacted with BT by hydrogen-bond from the phenolic hydroxyl and amino in protein. In the adsorption experiment, This hybrid biologic material show excellent performances for strontium ions adsorption and experimental data obey a pseudo second-order model of the chemical adsorption process. This study reported a new method for the producing of bio-based materials, which had the potential applications in waste water treatment. [ABSTRACT FROM AUTHOR]

In this work, a novel phosphorus functionalized carbon nitride (PCN) was designed and synthesized by a pyrolysis method for rapid adsorption of uranium. The optimized sample obtained at 600 °C (marked as PCN-600) exhibited the highest ability for uranium adsorption with efficiency of over 96% in only 1 min. The PCN-600 also exhibited high selectivity for uranium adsorption from simulated wastewater containing multiple interfering ions. The characterization results further revealed that the main adsorption mechanism of the uranium on PCN-600 is chemisorption. This work provides newly insight into adsorbent design for uranium removal from wastewater. [ABSTRACT FROM AUTHOR]