Surface Chemistry of Apatite at a Specific Concentration of 0.1 g/L: Phosphate Mineral

The importance of the effect of phosphate rock depends on the chemical form of phosphorus in which this element is combined. ∆pH=f(pH) curves of the phosphate system measured for different hydration durations have a common intersection point that corresponds to the IEPs. The point of zero charges (PZC) and isoelectric point (IEP) were defined using the derivative method, examining the variations at lower contact times. The various parameters, such as pH, coexisting ions, concentrations of suspensions, and contact time, which govern the interfacial chemistry and interaction pathways, are discussed to understand the adsorption process. The experimental shift in PZC observed at a short hydration is controlled by a surface dipole moment of this structure induced by the charge redistributions of adsorbed water molecules. During hydration, strong columbic interactions of water are occurring with the calcium and the phosphate ions of the apatite surface.