Effect of coexisting cations on the adsorption of cesium onto poly (β-cyclodextrin)/bentonite composite

A novel poly(beta-cyclodextrin)/bentonite composite (beta-CD/BNC) was successfully prepared through graft polymerisation by using ammonium persulphate-sodium bisulphate as initiators, and characterized by FT-IR and EDS. The equilibrium data fit Freundlich isotherm satisfactorily. Adsorption kinetic was fitted with pseudo-second-order. The maximum adsorption capacities for Cs+ by beta-CD/BNC in absence and presence of Na+ and Mg2+ were 48.83 +/- 0.35, 47.30 +/- 0.28, and 42.52 +/- 0.85 mg g(-1), respectively. Adsorption of Cs+ was suppressed by presence of Mg2+ more than Na+. beta-CD/BNC had a higher affinity to Cs+ than Na+ and Mg2+. beta-CD/BNC was an effective sorbent for the treatment cesium waste water.