/AnMtgsAbsts2009.53709 Smectite Clays Used as Templates to Synthesize Subnano-Sized Zero-Valent Iron for Reduction of Organic Contaminants.

Monday, November 2, 2009: 12:10 PM
Convention Center, Room 329, Third Floor

Cheng Gu1, Hanzhong Jia1, Stephen Boyd2, Brian Teppen1 and Hui Li2, (1)Department of Crop and Soil Science, Michigan State Univ., East Lansing, MI
(2)Department of Crop and Soil Sciences, Michigan State Univ., East Lansing, MI
In this study, a novel method was developed to synthesize clay-based subnano-sized zero-valent iron (ZVI).  Exchangeable Fe(III) cations were used to compensate the discrete negatively charged sites on smectite surfaces, followed by a reduction to ZVI by NaBH4. X-ray photoelectron spectroscopy confirmed the formation of ZVI. Clay interlayers were collapsed upon the Fe(III) reduction by NaBH4. These synthesized subnano-sized ZVI showed superior reactivity and efficiency to reduce organic contaminants, e. g. nitrobenzene. Over 90% of nitrobenzene (0.65 mM) was degraded within one minute, with the major intermediate of phenylhydroxylamine. Aniline was the final product accounting for about 94% of nitrobenzene after three-hour reaction. Smectite is a type of widely distributed clay in the environment, which can be constructed as a reactive domains for in situ remediation of many persistent contaminants in groundwater and subsurface soil.