4. Conclusion
A new adsorbent for heavy metal removal was successfully prepared
in this paper. Such prepared adsorbent has not only the
wormhole like mesopore structure with large surface area and pore
volume, but also the superparamagnetic character. These features make it an effective and convenient adsorbent for heavy metal
removal. The adsorption kinetics abides by pseudo second order
kinetic equation. The adsorption process could be well described
by intraparticle diffusion model and the adsorption rate of heavy
metals on this adsorbent was mainly controlled by the diffusion
rate within the pore. The adsorption process fitted well with Langmuir
isotherm. The prepared adsorbent performed better in neutral
pH condition, and was stable in strong acid and alkaline condition.
This adsorbent could be used in different water sources such as
river water, lake water, groundwater and tap water. The presence
of coexisting heavy metal ions avail heavy metal adsorption. In conclusion,
this thiol functionalized magnetic mesoporous silica is a
promising adsorbent for heavy metal removal from water.