Alginate-immobilized Aspergillus niger: Characterization and biosorption removal of thorium ions from radioactive wastewate

A novel alginate-immobilized Aspergillus niger microsphere (AAM) biosorbent was prepared and used for Th(IV) removal. Biosorption experiments indicated that the AAMs with an abundance of surface functional groups exhibited rapid complexation with Th(IV) and a superior biosorption performance (303.95 mg.g(-1)) at pH 6.0 and 40 degrees C. Multiple methods of characterizing the biosorbent revealed the successful immobilization of gap structures with increased surface area and multisorption sites (e.g., hydroxyl, carboxyl and protonated amine groups). A method that combined the superior Th(IV) biosorption ability along with inexpensive and eco-friendly microbe materials exhibited considerable potential as an immobilizing biosorbents for thorium preconcentrations. In addition, the biomaterial had good recyclability through immobilization and inactivation. The proposed biosorbent is effective for the removal of radionuclides from contaminated aqueous solutions.