Removal of Aqueous Cu2+ by Amorphous Calcium Carbonate: Efficiency and Mechanism

Crystalline calcium carbonate (CaCO3, such as calcite) could scavenge aqueous metals via adsorption and coprecipitation. As a precursor to crystalline CaCO3, amorphous (ACC) is poorly understood on removal. Herein, we synthesized silica-stabilized ACC investigated its Cu2+ removal efficiency mechanism. The results showed that the by controlled initial solution pH, concentration, contacting time, dosage. maximum capacity was 543.4 mg/g at an dosage of 1 g/L, pH 5.0, concentration 1000 mg/L, equilibrium time 20 h. X-ray powder diffraction (XRD) scanning electron microscope with energy dispersive spectrometer (SEM-EDS) revealed precipitated paratacamite (Cu2(OH)3Cl, space group: R3¯) whereas botallackite P21/m) Cu-bearing product for calcite using same ACC. However, preferred incorporate into calcite, which transformed from high loading (such 4 g/L). Our demonstrated crystallinity CaCO3 control