Inorganic particulates in removal of toxic heavy metal ions: Rapid and efficient removal of Zn(II) from aqueous solutions by sodium titanate

Removal behavior for Zn(II) ions from aqueous solutions at micro and tracer concentration levels has been carried out utilizing a 'radiotracer technique' through an adsorption process using synthesized and well characterized sodium titanate as an adsorbent. The study comprises of various physico-chemical parameters viz. concentration, temperature, pH and the effect of some added cations/anions and acid concentrations (HCl/H2SO4) on the adsorption process. The results show that the high uptake of Zn(II) on a sodium titanate surface follows first order rate law and that equilibrium data fit well for a Freundlich adsorption isotherm. A change in temperature (303-333 K) does not markedly affect the uptake of Zn(II) ions. Radiation stability of sodium titanate was also observed by exposing it to neutron and gamma rays from a 11.1 GBq (Ra-Be) neutron source having an integral neutron flux of 3.85 x 10(6) n/cm(2)/sec associated with gamma-dose of 1.72 Gy/h also using a gamma-cell (4.66 KGy/h) Co-60 source.