Adsorption of heavy metal ions by amino-functionalized CaCO_3 powder

Amino-functionalized CaCO3 powder was prepared with the direct deposition method and overlay method.The powder was tested as an effective adsorbent for some heavy metal ions such as Pb2+,Cu2+ and Mn2+.Techniques such as X-ray diffraction(XRD),energy dispersion spectrum(EDS) and scanning electron microscope(SEM) demonstrated that the material contained CaCO3.The functional groups(-NH2) were found at the surface of CaCO3 powder through infrared detection.The results show that the ammonia groups(-NH2) play a major role in the adsorption of heavy metal ions.The effects of adsorption time,the initial concentrations of heavy metal ions and the pH values of the solutions upon adsorption were studied.