Keywords: sorbents, hydrothermal synthesis, glass cullet, recycling, ion exchange, calcium silicate, pseudo–second–order kinetic modelling, recycled container glass, feedstock material, hydrothermal synthesis, tobermorite, batch sorption
11 Å tobermorite ion exchanger from recycled container glass
Waste container glass cullet has been evaluated as a feedstock material for the hydrothermal synthesis of tobermorite, a cation exchanger. Accordingly, it is demonstrated that essentially phase–pure 11 Å tobermorite, Ca5Si6O16 (OH) 2 · 4H2O, can be obtained from a stoicheiometrically–adjusted mixture of waste glass cullet and calcium oxide in aqueous sodium hydroxide at 100°C. A batch sorption study indicated that the cullet–derived tobermorite is highly effective in the removal of Pb2+ (1.66 mmol g–1) and Cd2+ (0.48 mmol g–1) from solution. Its ion exchange characteristics are compared with those of other waste–derived sorbents and potential applications are discussed.