Mechanisms of chromium(VI) removal from solution by zeolite and vermiculite modified with iron(II).

Mechanisms of Cr(VI) reduction by Fe(II) modified zeolite (clinoptilolite/mordenite) and vermiculite were evaluated. Adsorbents were treated with Fe(SO)·7HO to saturate their exchange sites with Fe(II). However, this treatment decreased their CEC and pH, probably due to the dealumination process.