3.2.4. Effect of adsorbent dosage
In a way of seeking an optimization for the adsorption process
of Cd2+ ions by nHAp, the effect of nHAp dosage was investigated
and plotted in Fig. 9. As expected, the Cd2+ sorption increased
rapidly with the nHAp dosage, as a consequence of increasing the
adsorption sites available for the Cd2+ ions removal. Interestingly
starting with 0.4 g of nHAp could achieve a Cd2+ removal efficiency
of 92%. Although the Cd2+ removal efficiency increases with the
nHAp dosage, the sorption capacity, which normalizes the Cd2+
uptake to the nHAp dosage, decreases [25]. Therefore, one should
customize the process to obtain the highest possible removal
efficiency for Cd2+ ions with the least amount of the nHAp dosage.