Selective removal of cesium by ammonium molybdophosphate - polyacrylonitrile bead and membrane

The selective removal of radionuclides with extremely low concentrations from environmental medium remains a big challenge. Ammonium molybdophosphate possess considerable selectivity towards cesium ion (Cs+) due to the specific ion exchange between Cs+ and NH4+. Ammonium molybdophosphate - polyacrylonitrile (AMP-PAN) membrane was successfully prepared for the first time in this study. Efficient removal of Cs+ (95.7%, 94.1% and 91.3% of 1 mg L−1) from solutions with high ionic strength (400 mg L−1 of Na+, Ca2+ or K+) was achieved by AMP-PAN composite. Multilayer chemical adsorption process was testified through kinetic and isotherm studies. The estimated maximum adsorption capacities even reached 138.9 ± 21.3 mg g−1. Specifically, the liquid film diffusion was identified as the rate-limiting step throughout the removal process. Finally, AMP-PAN membrane could eliminate Cs+ from water effectively through the filtration adsorption process.