ABSTRACT
Objective To optimize conditions for the preparation of amidoximated polyacrylonitrile (PAO) membrane for U (VI) adsorption that can be easily recycled and reused. Methods Using polyacrylonitrile powder as a raw material, the PAO membrane was prepared using the nonsolvent-induced phase separation method under different conditions. The effects of the polyacrylonitrile concentration and temperature and duration of amidoximation in the preparation of casting solution as well as alkali treatment before adsorption on the U (VI) adsorption performance of PAO membrane were investigated. Results Alkali treatment significantly improved the U (VI) adsorption performance of PAO membrane, and the temperature and duration of alkali treatment affected the U (VI) adsorption capacity. The optimal alkali treatment conditions were 0.1 mol/L NaOH, 80 min, and 60℃. The polyacrylonitrile concentration and temperature and duration of amidoximation in the preparation of casting solution influenced the adsorption performance of PAO membrane. The optimal preparation conditions were 10wt% polyacrylonitrile and amidoximation at 65℃ for 18 h. Under the optimal preparation and alkali treatment conditions, the U (VI) adsorption capacity of PAO membrane reached 255 mg/g. Conclusion The PAO membrane has the advantages of simple preparation, high adsorption capacity, and easy recycling and reuse, which can be used as an ideal material for adsorbing U (VI) in wastewater.