Selective removal of cesium by ammonium molybdophosphate-magnetic Fe3O4-chitosan composites

A new Cs + adsorbent, Fe 3 O 4 -chitosan particles combined with ammonium molybdophosphate (Fe 3 O 4 –CTS–AMP composite) were synthesized using a facile method through coordination between CTS and AMP. The surface morphology and chemical composition characterization indicated that Fe 3 O 4 –CTS particles and AMP particles were bonded tightly and the composite behaved superparamagnetically. Cs + adsorption properties of Fe 3 O 4 –CTS–AMP composites were studied. The adsorption data fitted well with pseudo-second-order kinetic model and Langmuir–Freundlich adsorption isotherms model. The adsorption equilibrium can be reached fast at 5 min. The maximum adsorption capacity was calculated as 177.8 mg g −1 . The composite also showed high selectivity for Cs + in coexistence with high concentration of competing cations. The adsorption mechanism of Cs + for the composite may mainly be the exchange of Cs + with NH 4 + . Therefore, the newly developed adsorbent is a kind of potential efficient composite for Cs + removal from wastewater. Graphic abstract