Iron oxides are common in natural waters, not the least in dystrophic waters, where large amounts of iron and humic substances are imported from the watershed. Iron interacts with various aqueous dissolved compounds; humic substances may coprecipitate with iron-oxide particles. Iron can catalyze the photodegradation of humic substances and colored dissolved organic matter (CDOM). In addition, light and iron interactively promote particle formation from dissolved humic substances. This is suggested to be due to photolysis products, including reactive oxygen species, which transform DOM into less soluble forms.
Moreover, oxic water iron (III) forms a complex with DOM, which stays in the solution. When the Fe(III)–DOM complex is exposed to UV light, the complex is broken, resulting in colloids of DOC and Fe(II). Fe(II) is oxidized into Fe(III) by photochemically produced H2O2, and the redox cycling (Fenton's reaction) is thereby complete. Possibly, humic colloids are stabilized by Fe(III) but are more prone to aggregation when the Fe(III)–DOM complex is broken. An indication that iron is important for the sedimentation of organic matter in lakes is the relationship between sediment carbon stock burial and total iron concentration in the lake water. If you are looking for high quality, high purity and cost-effective Iron oxide, or if you require the latest price of Iron oxide, please feel free to email contact mis-asia.
