3.1.2. FT-IR analysis FT-IR spectroscopy was used to compare the seashell powder before and after heavy metal biosorption (Fig. 2). The Cu(II) and Pb(II) loaded seashell powder spectra were established. The spectral data obtained for the samples revealed broad absorption peaks at 1786, 1455, 1082, 855, and 709 cm?1, which are common characteristic features of the carbonate ions in calcium carbonate and are the fund a mental modes of vibration for this molecule. The peak at 1077 cm?1 was only observed in the aragonite spectrum of calcium carbonate (Kamba et al.,2013). As seen in Fig. 2, there are obvious differences between the peak intensity of Cu(II) and Pb(II) loaded seashell powders.