A cobalt ferricyanide/ZIF-67/composted humus gel composite for improved cesium ion removal from wastewater

This study developed an innovative adsorbent—cobalt ferrocyanide/ZIF-67/aged garbage humus soil aerogel (PBA/ZIF-67/AARH aerogel)—specifically designed for the effective removal of cesium ions (Cs) from radioactive wastewater. The aerogel exhibited a maximum adsorption capacity of up to 51.92 mg/g, maintaining excellent Cs adsorption performance even in complex aquatic environments that contain other ions and dissolved organic matter (DOM). The experimental results showed that the adsorption effect of PBA/ZIF-67/AARH aerogel was the best when the dosage of PBA/ZIF-67/AARH aerogel was 0.01 g and pH value was 5. The adsorption capacity was 29.75 ± 0.5 mg/g. At the same time, PBA/ZIF-67/AARH aerogel has good regeneration stability. After five sorption-desorption cycles, the adsorption capacity is 20.1 ± 0.3 mg/g, and the Cs removal rate remains at 84.5 ± 0.5%. The PBA/ZIF-67/AARH aerogel also has a large specific surface area, reaching 30.7950 m 2 /g. Experimental analyses indicated that the Cs removal process aligns with both the Langmuir adsorption model and pseudo-second-order kinetics, revealing key mechanisms for adsorption efficiency, including ion exchange, functional group complexation, and the synergistic effects of cross-linking. This research provides a novel solution for the efficient removal of Cs, establishing a solid theoretical and practical foundation for future applications in pollution water treatment technologies. It holds significant potential for environmental protection and profound implications for human health.