Recovery of cesium from saline lake brine with potassium cobalt hexacyanoferrate-modified chrome-tanned leather scrap adsorbent

Abstract Potassium cobalt hexacyanoferrate was modified on alkali-hydrolyzed leather scrap (AHLS/KCoFC) to prepare a novel adsorbent for cesium (Cs + ) adsorption. AHLS/KCoFC was characterized with SEM, FT-IR, XRD, and XPS to affirm the correct modification. Batch experiments were performed to investigate the adsorption performance of AHLS/KCoFC for Cs + under various conditions, including pH, initial concentration, contact time and temperature. The equilibrium data was fitted well with Langmuir model and the maximum adsorption capacity was 36.75 mg g −1 at pH 6.0, 298.15 K and concentration 100 mg L −1 . Thermodynamic and kinetic studies showed that the adsorption process was spontaneous and endothermic, the pseudo-second-order kinetic model fitted accurately the data, and the adsorption process was controlled by intraparticle diffusion, but it was not the only rate-limiting step. Moreover, selective adsorption was investigated systematically. It was found that AHLS/KCoFC exhibited high selectivity for Cs + in presence of coexisting ions. At the optimum conditions, AHLS/KCoFC could be employed to the recovery of Cs + from saline lake brine, and the adsorption efficiency was achieved 97.33%, suggesting AHLS/KCoFC is potential application advantage as an efficient adsorbent.