Biogeochemical cycling of iron

ISOTOPIC VARIATIONS PRODUCED DURING BIOGEOCHEMICAL CYCLING OF IRON... 

Biogeochemical cycle of iron in the crustal-ocean-atmosphere factory. Source-. After Achterberg, E. R, et al. (2001). Analytics Chemica Acta 442, 1-14. 

Tortell PD, Maldonado MT, Granger J, Price NM (1999) Marine bacteria and biogeochemical cycling of iron in the oceans. EEMS Microb Ecol 29 1-11... 

Fig. 64. Scheme of vertical zoning and biogeochemical cycle of iron in the formation of iron-rich sediments (pH = 6 siderite, greenalite, and hydrogoethite are diagenetic, magnetite crystalline). 

Snyder, M., TaiUefert, M., and Ruppel, C. (2004). Redox zonation at the sahne-influenced boimdaries of a permeable surficial aquifer Effects of physical forcing on the biogeochemical cycling of iron and manganese. J. Hydrol. 296, 164—178. 

Roden E. E., Sobolev D., Glazer B., and Luther G. W. (in press) New insights into the biogeochemical cycling of iron in circumneutral sedimentary environments potential for a rapid microscale bacterial Fe redox cycle at the aerobic-anaerobic interface. In Iron in the Natural Environment Biogeochemistry, Microbial Diversity, and Bioremediation (eds. J. D. Coates and C. Zhang). Kluwer, (in press). 

Yamaguchi, K.E., Johnson, C.M., Berad, B.L., and Ohmoto, H., 2005. Biogeochemical cycling of iron in the Archaean-Palaeoproterozoic Earth constraints from iron isotope variations in sedimentary rocks from the Kaapvaal and Pilbara Cratons. Chem. Geol, 218, 135-69. 

The coupled biogeochemical cycling of iron and arsenic has also recently been studied in a system dominated by the addition of iron as an engineering practice.14 Since 1996, ferric chloride has been added as a coagulant to the Los Angeles Aqueduct in order to control the levels of naturally occurring arsenic that reach the water distribution system for the City of Los Angeles. The iron- and arsenic-rich floe formed by this process is deposited in North Haiwee Reservoir. Sediments and porewaters from this reservoir were examined to determine the extent to which arsenic and iron are remobilized in the sediments and to probe the speciation of arsenic in the solid phase and its possible effects on arsenic remobilization. 

Considerable evidence exists that human activities have already perturbed parts of the interlinked global biogeochemical cycles of the nutrients, micronutrients, carbon, and O2. Some of these perturbations are the consequence of climate change and others are associated with changes in the rates of input of nutrients and iron to the sea. As... 

Lundgren, D.G. Dean,W. (1979) Biogeochemistry of iron. In Trudinger, P.A. Swaine, D.J. (eds.) Biogeochemical cycling of mineralforming elements. Elsevier, 211-251... 

Lefevre, N., and Watson, A. J. (1999). Modehng the geochemical cycle of iron in the oceans and its impact on atmospheric CO2 concentrations. Global Biogeochem. Cycles 13(3), 727—736. 

Van Cappellen P., VioUier E., Roychoudhury A., Clark L., Ingall E., Lowe K., and DiChristina T. (1998) Biogeochemical cycles of manganese and iron at the oxic-anoxic transition of a stratified marine basin (Orca Basin, Gulf of Mexico). Environ. Sci. Technol. 32, 2931-2939. 

Lnndgren, D. G. and W. Dean. 1979. Biogeochemistry of iron. In P. A. Trnndinger and D. J. Swaine (eds.) Biogeochemical Cycling of Mineral-Forming Elements. Elsevier, Amsterdam, pp. 211-251. 

Fig. 6.5 Microbial iron and sulfur cycles that may have dominated biogeochemical cycling before the origin of oxygenic photosynthesis, aerobic respiration and possibly before the use of oxides of nitrogen.

We can see that the soluble and exchange forms of these metals are present in small amounts accounting merely for a few percent of the total metal content in soil. The content of organometal species is relatively high in the upper profile rich in humic species, whereas it drops sharply in the mineral horizons. Copper is extensively involved in the biogeochemical cycle in the Forest ecosystems and this is less profound for cobalt. It is noteworthy that a large part of metals (in particular, of copper) become bound to iron hydroxides. This is typical for various trace elements, including arsenic, zinc and other elements with variable valence. 

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