Efficient adsorption of radioactive iodide ion from simulated wastewater by nano Cu2O/Cu modified activated carbon

•Nano Cu2O/Cu-carbon composite was firstly synthesized to adsorb I− from wastewater.•Instrumental analyses indicate the 80-100 nm nano Cu2O/Cu loaded on activated carbon.•I− adsorption by the nano Cu2O/Cu-carbon composite up to 41.2 mg/g was observed.•Wide pH range, excellent interfering ions resistance of I− adsorption were obtained.•Adsorption mechanism involves complexation and precipitation on the composite.

Nano Cu2O/Cu modified activated carbon composite (nano Cu2O/Cu-C) was firstly synthesized by a simple and efficient hydrothermal method and used to adsorb iodide ion (I−) from simulated radioactive wastewater. Nano Cu2O/Cu loaded and uniformly distributed on activated carbon with a diameter of 80-100 nm. The composite exhibited excellent adsorption performance, which was primarily attributable to the synergistic effect of nano Cu2O/Cu and activated carbon. Langmuir isotherm and pseudo-second-order kinetic model accurately represented the experimental data of I− adsorption. On the basis of the Langmuir isotherm, the maximum adsorption capacity of I− by nano Cu2O/Cu-C was 41.2 mg/g, which is significantly higher than pure nano Cu2O and activated carbon. The adsorption was affected only slightly by pH and other interfering ions. Additionally, X-ray photoelectron spectroscopy was used to elucidate the possible adsorption mechanism. This study provides new insight into the fabrication and practical application of high-performance adsorbent in removing radioactive I− from wastewater.

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