Polyethyleneimine/hydrated Titanium Oxide-Functionalized Fibrous Adsorbent for Removing Cobalt: Adsorption Performance and Irradiation Stability.

Radionuclides of Co-60 often encountered in the fields of radiation therapy, medical preparation, and equipment sterilization, which have been considered fatal. Therefore, developing efficient and irradiation-stable adsorbents for the removal of Co-60 in wastewater is urgently needed. An irradiation-stable fibrous adsorbent was fabricated through the surface functionalization of collagen fibers (CFs) by polyethyleneimine (PEI) and hydrated titanium oxide (TiO) (PEI-TiO-CFs). PEI-TiO-CFs, including their adsorption performance and irradiation stability, were systematically investigated. Results showed that PEI-TiO-CFs exhibit a maximum adsorption capacity of 0.5575 mmol g(-1). In addition, the adsorption capacity of PEI-TiO-CFs only demonstrated a slight decrease in the selectivity investigation of Co2+ mixed with another coexisting ion, such as Na+, K+, and NO3-, Cl-. Furthermore, breakthrough point of PEI-TiO-CFs in column is high at 80 BV (bed volume) and the PEI-TiO-CF column can be mostly regenerated using 12 BV of Na2EDTA solution. Excellent irradiation stability of PEI-TiO-CFs was confirmed by the maintained morphology and adsorption capacity after irradiation at 350 kGy of Co-60 gamma-ray. Results indicated that PEI-TiO-CFs are an effective adsorbent for radioactive cobalt removal from aqueous solutions.