Biomaterial Database

Insights into phenanthrene attenuation by hydroxyl radicals from reduced iron-bearing mineral oxygenation. 2022

Longliang Wang, and Haiyan Du, and Huacheng Xu, and Huan Li, and Lina Li

State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing, China.

The oxygenation of Fe(II)-bearing minerals for hydroxyl radicals (HO•) formation and contaminant attenuation receive increasing attention, while the mechanisms for specific Fe(II) species in manipulating HO• formation and contaminant attenuation are unclear. Herein, a total of four Fe(III)-bearing minerals were applied in the reduction-oxygenation processes to produce HO•. Results showed that the total HO• generated from the Fe-(oxyhydr)oxides were significantly higher than those from the Fe-silicates, with the order of goethite and hematite (~1500 μmol kg-1) > Fe-montmorillonite (~550 μmol kg-1) > chlorite (~120 μmol kg-1). The HO• formation was largely hinged on the reactive Fe(II) species, i.e., the surface-adsorbed/low-crystalline Fe(II) in the Fe-bearing minerals. For the co-incubation of minerals and phenanthrene, the concentrations of phenanthrene decreased from the initial 3.0 mg L-1 to 0.7 mg L-1 and 1.9 mg L-1 for Fe-montmorillonite and goethite, respectively, suggesting the HO• mediated by the Fe-montmorillonite was more conducive for phenanthrene attenuation. The goethite tended to promote the formation of free HO•, while the Fe-montmorillonite with interlayer structure can provide attachment sites for the surface-adsorbed/low-crystalline Fe(II), resulting in high potential for surface-bound HO• formation and phenanthrene attenuation. This study highlights the importance of Fe-bearing minerals in manipulating HO• formation, providing new insight into the removal of contaminants in ecosystems.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D008903	Minerals	Native, inorganic or fossilized organic substances having a definite chemical composition and formed by inorganic reactions. They may occur as individual crystals or may be disseminated in some other mineral or rock. (Grant & Hackh's Chemical Dictionary, 5th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Mineral
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010616	Phenanthrenes	POLYCYCLIC AROMATIC HYDROCARBONS composed of three fused BENZENE rings.
D005290	Ferric Compounds	Inorganic or organic compounds containing trivalent iron.	Compounds, Ferric
D005296	Ferrous Compounds	Inorganic or organic compounds that contain divalent iron.	Compounds, Ferrous
D001546	Bentonite	A colloidal, hydrated aluminum silicate that swells 12 times its dry size when added to water.	Montmorillonite,Montmorrillonite
D017665	Hydroxyl Radical	The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.
D017753	Ecosystem	A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)	Ecosystems,Biome,Ecologic System,Ecologic Systems,Ecological System,Habitat,Niche, Ecological,System, Ecological,Systems, Ecological,Biomes,Ecological Niche,Ecological Systems,Habitats,System, Ecologic,Systems, Ecologic