The silica obtained from rice husk was digested with 8 M HNO3 for
3 hrs and was burned in furnance at 700o
C for 4 hrs and prepared for silica gel. The
silical gel was reflux with the mixture of ethylene sulfide and 3-aminopropyl
trimethoxy silane in toluene for 3 days. The sorbent was identified functional groups
by FT-IR and analyzed the elements by CHNS/O analyzer. For the batch
experiments, 20 ml of Zn(II) solutions was mixed with adsorbent and shaken. The
effect of parameters such as sorbent dosages (0.01-0.30 g), pH (1-7), contact times
(10-360 mins), temperature (10-50o
C), the interference of some heavy metals Pb(II),
Cd(II), Hg(II) and As (III) were studied. The optimum conditions such as the packed
with sorbent height and flow rate of solution for the column method were studied. The
adsorption data was analyzed by Langmuir isotherm model and sorption capacity was
calculated from Freundlich model.