Sorption of lead ions on diatomite and manganese oxides modified diatomite

Naturally occurring diatomaceous earth (diatomite) has been tested as a pot ential sorbent for Pb(II) ions, The intrinsic exchange properties were furt her improved by modification with manganese oxides. Modified adsorbent (ref erred to as Mn-diatomite) showed a higher tendency for adsorbing lead ions from solution at pH 4. The high performance exhibited by Mn-diatomite was a ttributed to increased surface area and higher negative surface charge afte r modification. Scanning electron microscope pictures revealed a birnessite structure of manganese oxides, which was featured by a plate-like-crystal structure. Diatomite, filtration quality was improved after modification by manganese oxides. Good filtration qualities combined with high exchange ca pacity emphasised the potential use of Mn-diatomite in filtration systems. (C) 2001 Elsevier Science Ltd. All rights reserved.