Efficient adsorption of Cs(I) and Sr(II) ions from solution by xanthate modified sponge-like chitosan

• Sponge-like chitosan-based adsorbent (CTS-SX) was synthesized via xanthate-modification. • The maximal adsorption capacity for Sr(II) and Cs(I) was 76.21 and 133.15 mg·g −1 respectively. • Xanthate modification improved the number of active sites and hydrophobility of CTS-SX. • CTS-SX is potential for adsorptive removal of Sr(II) and Cs(I) from radioactive wastewater. Efficient removal of radionuclides from radioactive wastewater is vital for ensuring the sustainable development of nuclear energy. Herein, xanthate-modified sponge-like chitosan-based adsorbent (CTS-SX) was synthesized through a facile method, which exhibited excellent adsorption performance for Sr(II) and Cs(I). The maximum adsorption capacity of Sr(II) and Cs(I) reached 76.21 and 133.15 mg·g −1 respectively. Various models were used to fit the adsorption process, and the results indicated that the adsorption process of Sr(II) was best fitted by Freundlich isotherm model and phenomenological internal mass transfer kinetic model, while the adsorption of Cs(I) was best fitted by Langmuir isotherm model and Langmuir kinetics model. In addition, the adsorption performance in binary-component system, influence of pH and competing ions were also explored. In summary, the modification could improve the amount of active sites and hydrophobility of CTS-SX. With excellent adsorption performance and simplicity of separation, CTS-SX has potential in application for radioactive wastewater treatment.