Study on adsorption behavior and mechanism of U(VI) by geological cement

For the radioactive uranium-containing waste liquid, the static adsorption behavior of U(VI) by geological cement was studied by changing cement dosage, contact time, pH, U(VI) concentration, and solution temperature using the batch adsorption method in the experiment. The experimental results show that the adsorption rate of U(VI) is over 99.9% under the condition of low solid-liquid ratio (0.5 g/L) and a short period of time (1.5 d), and the U(VI) concentration and environmental factors such as pH and temperature have little effect on the adsorption capacity, so the adsorption conditions are very mild. The thermodynamic behavior is more consistent with the Langmuir model, meaning that the U(VI) adsorption by geological cement is a monolayer adsorption-based process. The analysis results of material characteristics show that there are physical and chemical coexistence adsorption mechanisms for the U(VI) adsorption by geological cement. (authors)