High efficient adsorption for thorium in aqueous solution using a novel tentacle-type chitosan-based aerogel: Adsorption behavior and mechanism

A novel tentacle-type chitosan-based aerogel with swelling resistance was prepared via sol-gel technology using resorcinol as enhancer and g-C3N4 as tentacle. The introduction of resorcinol and g-C3N4 could not only increase the stability of the chitosan-based aerogel but also reduce the inter-molecular and intra-molecular interactions in chitosan, thereby enhancing the response of active sites to thorium. The adsorption performance of the chitosan-based aerogel for thorium from solution was verified by static and dynamic adsorption experiments. The results showed that the chitosan-based aerogel possessed an outstanding adsorption property for thorium with a short equilibrium time (20 min), a fast adsorption rate (103.9 mg/(g.min)), a high removal efficiency at low concentration (99.4 %) and a large static saturated adsorption capacity (526.2 mg/g). The dynamic adsorption experiments showed that the maximum dynamic adsorption capacity of the chitosan-based aerogel reached about 499.7 mg/g, which was consistent with static adsorption, far exceeding the reported chitosan-based adsorption materials. The results indicated that the capture of thorium on the tentacle-type chitosan-based aerogel was controlled by various factors, such as electrostatic interactions, surface complexation and cation-pi effect. In a word, the tentacle-type chitosan-based aerogel could be used as a promising adsorbent for the remediation of thorium-containing wastewater.