Iron oxides catalyze the conversion of hydrogen peroxide (H(2)O(2)) into oxidants capable of transforming recalcitrant contaminants. Unfortunately, the process is relatively inefficient at circumneutral pH values because of competing reactions that decompose H(2)O(2) without producing oxidants. Silica- and alumina-containing iron oxides prepared by sol-gel processing of aqueous solutions contai...

The aim of this paper is to assess the effect of liming and low doses of municipal sewage sludge (5%, 10%, 15% of the soil mass) on lead, chromium and nickel speciation in soil. The 420-day experiment was carried out in laboratory conditions. In all the samples lead, chromium and nickel concentration was determined with the ICP-AES method, while the content of those metals in different fraction...

Reduction of crystalline Fe(III) oxides is one of the most important electron sinks for organic compound oxidation in natural environments. Yet the limited number of isolates makes it difficult to understand the physiology and ecological impact of the microorganisms involved. Here, two-stage cultivation was implemented to selectively enrich and isolate crystalline iron(III) oxide reducing micro...

Total concentrations and fractionation of Cu, Zn and Pb in seven operationally defined phases (exchangeable, carbonates, manganese oxides, organic complexes, amorphous iron oxides, crystalline iron oxides and residual) were determined in sediments colonised by the halophyte species Halimione portulacoides and Spartina maritima in a Tagus estuary salt marsh (Portugal). We aimed to determine whet...

The western region of the southern Pantanal is characterised by soils with high phosphorus (P) contents, derived from materials surrounding lithostratigraphic units, accumulated fluvial transport. However, studies on forms and availability P in these are scarce. objective this study was to evaluate different inorganic their relationship some attributes carbonatic Mato Grosso do Sul, Brazil. Hed...

3. Soluble Metal Oxides 2459 3.1. Polyoxometalates 2459 3.2. Peroxotungstates 2459 3.3. Peroxomolybdates 2460 3.4. Methyltrioxorhenium 2461 3.5. Other Metal Oxides 2461 4. Metal Oxides Generated in Situ 2461 4.1. Selenium and Arsenic Compounds 2461 4.2. Simple Metal Salts 2462 5. Coordination Complexes 2463 5.1. Manganese Porphyrins 2463 5.2. Iron Porphyrins 2464 5.3. Manganese Salen Complexes ...

Heavy metals contamination threat to the environment is a big concern. Predicting the movement of heavy metals such as Cd in soil is an important goal. In this study the effect of soil chemical and physical properties on Cd mobility were done using a thin layer chromatography (Soil TLC). The soils used in this research have a wide range of organic matter (2.1-29 g/kg), pH value (4.9-8.8), CEC (...

Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully rec...

Adsorption of heavy metals and radionuclides (HMR) onto iron and manganese oxides has long been recognized as an important reaction for the immobilization of these compounds. However, in environments containing elevated concentrations of these HMR the adsorptive capacity of the iron and manganese oxides may well be exceeded, and the HMR can migrate as soluble compounds in aqueous systems. Here ...

We have hypothesized (Negro et al. 1999) that bearded vultures, Gypaetus barbatus, deliberately stain their plumage with iron oxides to signal dominance status. The conceptual frame to which we ascribe our hypothesis is the handicap principle (Zahavi & Zahavi 1997). For a signal to convey reliable information, and thus to evolve, it has to be costly (Zahavi 1975), and we proposed that the assoc...