The contribution of free iron oxides to positive and negative charge distribution has been studied on soils and synthetic kaolinite-iron oxide complexes over a wide range ofpH values. The charge on the iron oxides is pH-dependent, being positive at low and negative at high pH values, respectively, and accounts for a considerable proportion of the pHdependent negative charge in soils. Iron oxide...

Cyanobacteria require large quantities of iron to maintain their photosynthetic machinery; however, in most environments iron is present in the form of insoluble iron oxides. Whether cyanobacteria can utilize these sources of iron, and the potential molecular mechanisms involved remains to be defined. There is increasing evidence that pili can facilitate electron donation to extracellular elect...

A facile and sustainable protocol for synthesis of six different shaped iron oxides is developed. Notably, all the six shapes of iron oxides can be synthesised using exactly same synthetic protocol, by simply changing the precursor iron salts. Several of the synthesised shapes are not reported before. This novel protocol is relatively easy to implement and could contribute to overcome the chall...

welders may suffer from welding fumes generated during the process if the ventilation systems are improperly applied. the objective of the present work was to study the mitigation of air pollutants at welding stations, using different ventilation scenarios. four air pollutants including iron oxide, respirable dust, ozone, and carbon monoxide were measured during four different ventilation scena...

The reductive dissolution of poorly crystalline ferric oxides in the presence of cysteine was investigated to evaluate the potential of cysteine as a possible electron carrier to stimulate the reduction of iron(III) oxides by Geobacter sulfurreducens. The extent and rate of biotic and abiotic reduction of iron(III) oxides in the presence of cysteine at various concentrations were compared. Iron...

The availability of iron has been thought to be a main limiting factor for the productivity of phytoplankton and related with the uptake of atmospheric CO(2) and algal blooms in fresh and sea waters. In this work, the formation of bioavailable iron (Fe(II)(aq)) from the dissolution of iron oxide particles was investigated in the ice phase under both UV and visible light irradiation. The photore...

The response of the ocean redox state to the rise of atmospheric oxygen about 2.3 billion years ago (Ga) is a matter of controversy. Here we provide iron isotope evidence that the change in the ocean iron cycle occurred at the same time as the change in the atmospheric redox state. Variable and negative iron isotope values in pyrites older than about 2.3 Ga suggest that an iron-rich global ocea...

different types of iron oxides deposits have been identified along the khaf – dorouneh volcanic and plutonic belt in north east of iran. kuh-e-zar is one of these ore deposits known as fe- oxide gold deposit. the main purpose of this paper is to detect and discriminate the iron oxide minerals in this area based on the etm+ data. data processing has been done by envi (environment for visualizing...