Copper hexacyanoferrate nanoparticle-decorated biochar produced from pomelo peel for cesium removal from aqueous solution

A microporous composite (CuHCF/PP600) for cesium removal was successfully prepared by copper hexacyanoferrate (CuHCF) dispersed into a biochar (pomelo peel was carbonized at 600 °C). In comparison with CuHCF/PP600 and pure CuHCF, it was showed that CuHCF/PP600 had better performances on sedimentation and cesium removal. The maximum removal efficiency of cesium by the composite is 30.06 mg/g (at pH 7.0). Adsorption kinetic and isotherm of CuHCF/PP600 were followed to Langmuir isotherm model and pseudo-second-order kinetic model respectively. Thermodynamic analysis shows that the adsorption process was endothermic. The removal efficiency of Cs+ was down less than 5% in the presence of Na+, K+, Mg2+. The results indicate that CuHCF/PP600 is a promising adsorbent for cesium removal from aqueous solution.