11 Å tobermorite from cement bypass dust and waste container glass: A feasibility study

Abstract

A novel one-step hydrothermal synthesis of 11 Å tobermorite, a cation exchanger, from a unique combination of waste materials is reported. 11 Å tobermorite was prepared from stoicheiometric quantities of cement bypass dust and waste container glass at 100 °C in water. The product also comprised 10 wt.% calcite and trace quartz as residual parent phases from the cement bypass dust. In a batch sorption study at 20 °C the uptakes of Cd 2+ and Pb 2+ by the waste-derived tobermorite product were found to be 171 mg g − 1 and 467 mg g − 1 , respectively, and in both cases the removal process could be described using a simple pseudo-second-order rate model ( k 2 = 2.30 × 10 − 5 g mg − 1 min − 1 and 5.09 × 10 − 5 g mg − 1 min − 1 , respectively). The sorption characteristics of the 11 Å tobermorite are compared with those of other waste-derived sorbents and potential applications are discussed.