Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 231-843-4
CAS number: 7758-94-3
For inorganic substances present in the natural environment, discussion
is necessarily qualitative and modeling processes cannot be used easily.
For an ubiquitous substance, the measured environmental concentrations
(see discussion of Environmental fate and pathways) constitute
sufficient information about ultimate environmental fate and behaviour.
Under normal aerobic environmental conditions, anthropogenic iron salt
emissions will primarily mineralise with water, precipitate as ferric
hydroxide and be incorporated into soil and sediment, and participate in
the natural geochemical processes of iron. Under anaerobic conditions or
low pH other processes will dominate the environmental fate of iron.
Soil is the primary reservoir of naturally occurring iron. It has its
own surface geochemical cycle. Iron can be mobilized from soil or
sediment to surface waters as colloidal ferric hydroxide, fine suspended
particulates and inbound to clay silt. Factors like pH, CO2
concentration, redox conditions, availability of organic and inorganic
complexing agents and soil type contribute to reactions of iron in soil.
In soil iron can be bound to organic humic substances (see below), which
can be soluble, colloidal or precipitates depending on the environmental
factors (Lahermo et al 1996).
Mass balances and precipitation of iron were studied in two acidified
(pH < 5) Czech lakes in 2000 - 2003, where influent iron was mainly in
the organically bound form. Photochemical reactions were observed to
liberate iron to the inorganic form, subject to precipitation of iron
hydroxides. These hydroxides were concluded to decrease the availability
of orthophosphate to phytoplankton, and to increase the amount of iron
hydroxides in lake sediment, changing its phosphate sorption
characteristics (Kopácek et al. 2005).
Sediments contain Fe(III) as insoluble oxides, but also in an
organically complexed and colloidal state. Even though 60 – 80 % of iron
is bound to silicates in marine sediments, Fe(III) hydroxides are
considered to be the main species linked to binding and cycling of
phosphorus in surface waters. They can act as chemical coagulants of
external phosphorus loading but also as internal source of phosphorus
under strong reducing conditions, caused e.g. by sedimented organic
matter. Basic environmental factors are as availability of oxygen, pH,
sulphate, microbiological reduction and sedimented organic matter.
Dynamics of phosphorus has been studied in brackish marine sediments
(Gulf of Finland) in detail (Lehtoranta 2003).
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again