Before use, cuttlefish bone was rinsed with deionized water,
boiled for 10 min to desorb any impurities, dried at 103–105 8C for
24 h and allowed to cool in a dessicator. Turner et al. [25] showed
that the performance of defluoridation of water was very good
(90–96%) for small particles (150–300 mm) of calcite: the
thermodynamically stable variety of calcium carbonate at room
temperature. In our study, cuttlefish bone was crushed and sieved.
The sorption properties of 150–200 mm-particles were studied.
The X-ray diffraction pattern of the cuttlefish bone was recorded by
a D8 Bruker X-ray diffractometer (Germany). The XRD data were
matched with standard JCPDS data files. Elemental analysis was
conducted by a Philips PW 104 wavelength dispersive sequential
XRF (X-ray fluorescence) analyzer, with less than 2% error. The
spectroscopic studies were performed by using a scanning electron
microscopy (SEM, Hiatchi S2500). The Brunauer–Emett–Teller (BET)
surface area was determined by the low temperature N2 adsorption
method. The pH of the zero point charge (pHzpc) was determined by
placing 1 g of cuttlefish bone into 250 mL glass stopper bottle