Si-substituted carbonate hydroxyapatite (Si-CHAP) was obtained by embedding silicate and carbonate into hydroxyapatite prepared from egg-shell via sonochemistry coprecipitation. Batch experiments were performed to investigate the effect of contact time, solution pH and temperature on the adsorption of Cu2+ by Si-CHAP. Our results showed that the maximal adsorption capacity, Qm of Cu2+ reached to 246.80 mg g–1 at pH 5.7, and at 90 min contact time under 313 K. Adsorption kinetics followed pseudo-second order. The equilibrium process fit the Lan...