Effect of Acid Treatment on the Structural Properties and Bleaching Performance of Montmorillonite

Montmorillonite may be an alternative low-cost adsorbent because it is naturally available and possesses peculiar physiochemical properties.The present work investigates the effect of acid treatment on the structural propertise and bleaching capacity of the sodium montmorillonit which was supplied from north of kerman province . The sample was leached with different HCl concentration (2,4 and 6 molar) at 80◦C for 8h . Acid treatment had a significant influence on the structure of montmorillonite layers. XRD patterns showed that the crystallinity of leached sample is decreased with increasing acid concentration and in 6 molar HCl the peaks of montmorillonite totally are disappeared . These results can be related to the fromation of amorphous product . During acid treatment , interlayer cations (Na+) of montmorillonite are replaced with H+ ions and then structural cations are dissolved . Chemical analysis of leached sample exhibited higher leaching of MgO than Al2O3 in octahedral sheet which it clearly shows that Mg2+ ions are more prone to acid attack . Most efficient bleaching capability of montmorillonite and also maximum surface area was obtained by treatment with 6 molar acid.

Keywords:

Acid treatment , Adsorption , Bleaching , Montmorillonite