Journal of Hazardous Materials 2014-08-15

Sulfurized limonite as material for fast decomposition of organic compounds by heterogeneous Fenton reaction.

Kei Toda, Toshinori Tanaka, Yutaka Tsuda, Masahiro Ban, Edwin P Koveke, Michio Koinuma, Shin-Ichi Ohira

Index: J. Hazard. Mater. 278 , 426-32, (2014)

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Abstract

Rapid decomposition of wastewater contaminants using sulfurized limonite (S-limonite) was investigated. Limonite is used for desulfurization of biogases, and S-limonite is obtained from desulfurization plants as solid waste. In this work, the profitable use of S-limonite in water treatment was examined. The divalent Fe in S-limonite was expected to produce OH radicals, as Fe(2+) ions and limonite thermally treated with H2 do. Methylene blue was used for batch-wise monitoring of the decomposition performance. The decomposition rate was fast and the methylene blue solution color disappeared in only 10s when a small amount of H2O2 was added (1mM in the sample solution) in the presence of S-limonite. The OH radicals were formed by a heterogeneous reaction on the S-limonite surface and Fenton reaction with dissolved Fe(2+). The decomposition of pentachlorophenol was also examined; it was successfully decomposed in batch-wise tests. The surfaces of limonite before sulfurization, S-limonite, and S-limonite after use for water treatment were performed using scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that S-limonite reverted to limonite after being used for water treatment. Copyright © 2014 Elsevier B.V. All rights reserved.