ferric hydroxide

Ferric hydroxide is thought to be responsible for the pronounced reddish color of Mars.

If exposed to oxygen, this is converted to ferric hydroxide, the familiar reddish brown rust.

The iron is oxidized to ferric hydroxide upon encountering the oxidizing environment of the surface.

However, on exposure to air, this is oxidized and precipitated as ferric hydroxide, which is usually removed from the water before use.

For instance, it is possible to use a ferric hydroxide floc to remove radioactive metals from aqueous mixtures.

The reek of ferric hydroxide, ferric oxide, call it rust, washed in bitter waves across the bed.

Natural minerals give true colour to water; for example, calcium carbonate in limestone regions gives a greenish colour, ferric hydroxide, red.

In continuous processes, a filter medium containing manganese dioxide oxidizes the iron and removes it as the ferric hydroxide.

Examples include decomposition of hydrates such as ferric hydroxide to ferric oxide and water vapor.

Local films of ferrihydrite are present on the surface of the spring and there is an orange ferric hydroxide crust on the stream bed downstream.

Rust, a mixture of ferric hydroxide compounds, illustrates the low solubility of ferric ions in water.

Thus detrital ferric hydroxides including goethite and ferrihydrite will spontaneously transform into red colored hematite pigment with time.

The major iron phase in the sediments is X-ray amorphous ferric hydroxide. Chlorite is the major ferrous mineral.

These colors are due to the accumulation of ferric hydroxide and manganic oxide deposited with the mucilage and minerals that comprise the lorica.

With the use of lime, the iron present in AMD can be completely removed as ferric hydroxide at pH 3.5, following oxidation with H202.

The use of DDA in the first step to reduce co-precipitation of other metal ions onto ferric hydroxide sludge slightly improved the subsequent Zn recovery.

Van Houten (1961) developed the idea to include the in situ (early diagenetic) reddening of the sediment by the dehydration of brown or drab colored ferric hydroxides.

In a solution containing both iron(II) and iron(III), ferric hydroxide precipitates between pH 2 to 4:

The other method consists in ageing stoichiometric mixtures of ferrous and ferric hydroxides in aqueous media, yielding spherical magnetite particles homogeneous in size.

If the pH is greater than 4.0, the final step is the precipitation of ferric hydroxide floc and the liberation of more acid in a reaction known as hydrolysis.

After the radioisotopes are absorbed onto the ferric hydroxide, the resulting sludge can be placed in a metal drum before being mixed with cement to form a solid waste form.

Following sample preparation, uranium and thorium are pre-concentrated on ferric hydroxide and then separated using UTeva resin (EIChroM Industries).

These ferric hydroxides commonly include goethite (FeO-OH) and so called "amorphous ferric hydroxide" or limonite.