A rare kind of mineral which scientists hope could be used to remove toxic metals and radioactive species from the environment played a similar, crucial role early in Earth’s history.
Research carried out by an international team of leading biogeochemists suggests for the first time that ‘green rust’ was likely widespread in ancient oceans and may have played a vital role in the creation of our early atmosphere.
Led by Newcastle University, UK, the study shows that during the Precambrian period, green rust ‘scavenged’ heavy metals such as nickel out of the water. Nickel availability is linked to the production of methane by anaerobic organisms, which is a major sink for oxygen produced during photosynthesis, and thus green rust played a crucial role in the oxygenation of the Earth’s atmosphere.
Only discovered in the last decade, green rust is a highly reactive iron mineral which experts hope could be used to clean up metal pollution and even radioactive waste.
Newcastle University’s Professor Simon Poulton said this latest discovery – published this month in the academic journal Geology – proved the effectiveness of green rust as an environmental cleaner.
“Because it is so reactive, green rust has hardly ever been found before in nature and never in a water system like this,” explains Professor Poulton, who led the research team involving experts from the Universities of Newcastle, Nancy, Southern Denmark, Leeds, Brussels and Kansas, and the Canadian Light Source and Indonesian Institute of Sciences.
“The discovery of green rust in Lake Matano, Indonesia, where we carried out our experiments shows for the first time what a key role it played in our ancient oceans – scavenging dissolved nickel, a key micronutrient for methanogenesis.”
Dr Sean Crowe of the University of Southern Denmark explains: “We still know relatively little about green rust but our research shows that it is likely to be much more prevalent in the environment than has previously been recognised and the role it plays in cycling elements such as nickel and other metals is significant.
“Understanding the important role it played in our past and its effectiveness at removing metals from the environment will help us to understand how we might be able to use it to clean up polluted land and water in the future.”
The high reactivity of green rust is the reason it could be so much help in cleaning up polluted sites. The rust reduces elements like chromium, uranium and selenium, significantly reducing their solubility and mobility in the environment, and in some cases absorbing them into the rust’s molecular structure.
Professor Poulton adds: “Green rust has received a lot of attention recently due to its possible role as a pollutant mediator, but it is particularly exciting to think that this may have been a natural process throughout huge periods of ancient Earth history.”
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Khwarizmi says:
June 27, 2012 at 7:21 am
I think the point being made was CH4 oxidizes in the atmosphere to CO2, and thus methane likely was a sink for early oxygen production.
Mike Bromley the Kurd says:
June 27, 2012 at 5:52 am
And why do I get the feeling that this is all hocus-pocus? The wording is kindergarten in tone, and the gist is mysterious and cloistered. ….
Green, grey and blue states of iron are common in clays in marshes and swamps where low oxygen levels lead to reduced valence states of iron. I would suspect that the obscure approach here is either because the authors are treating the MSM as simpletons – not unreasonable, or they are protecting something that someone hopes is patentable. Given the “uses” jargon, I think the latter is most likely.
The journal “Geology” is usually paywalled but this paper is open access:
http://geology.gsapubs.org/content/40/7/599.full.pdf+html
The most uninformative press release. Couldn’t they have described the stuff. It reads like they are just speculating about the possible existence of such a thing. Commenters at WUWT, as usual, are more informative than the piece under consideration.
….reminds me of “polywater.” http://www.cs.cmu.edu/~dst/ATG/polywater.html
The word species is most commonly used in biology, but it is also used in chemistry to refer to a specific kind of chemical or molecule such as CH4, L-lysine, N2 and so on.
One thing that bothers me about these “age of” claims for the Earth, Cambrian, Triassic or whatever is that they never discuss how the system gets to “”zero” and the what is meant by a phrase such as “the age of the Earth.” One thing nobody believes is that God made the Earth ex nihilo 4.5 billion years ago. Young-Earth Creationists believe God made the Earth and the universe ex nihilo around 6kya. Scientists believe the Big Bang occurred over 12 billion years ago creating the Universe, and that the Earth was formed from supernova remnants about 4.6 billion years ago. There is too little discussion about how we got from the old giant star to the current system, and what point in the process was 4.6 bya.
CRS, Dr.P.H. says:
June 27, 2012 at 3:28 pm
Yes, polywater. I attended the seminar in which polywater was debunked. It was at Stevens Institute of Technology in NJ. That was one important event in my subsequently long scientific career when I learned not to believe almost anything I had read, but to reason it out for myself. Such “non-consensus” thinking allowed me later to invent some useful things.
Hoser – The oxidation mechanism you apply to the ambiguous paragraph confers a degree of plausibility to the hypothesis that it simply doesn’t have in its published form. Good stuff.
But methane is an unstable molecule and will dissociate without the need for oxygen. That is the reason why NASA and the European Space Agency applied the principle of mediocrity to Titan when attempting to explain the abundance of methane on the orange moon:
“…unlike water in the Earth’s atmosphere that continually renews itself, methane is destroyed by ultraviolet light, so Titan must have a source deep inside, scientists said.”
–Titan’s Methane Not Produced by Life, Scientists Say
http://esse.engin.umich.edu/PSL/PRESS/Titan_Cassini_Huygens/AP_Wire_012705.pdf
NASA moedlling suggests that dust storms and electrical charges can destroy methane.
So do we need the green rust to explain anything?
Afterall, “Titan exhibits many similarities to conditions that may well once have prevailed on Earth.”
http://www.esa.int/SPECIALS/Cassini-Huygens/SEM3782VQUD_0.html
These conditions include abiotic production of hydrocarbons by serpentinization, a process that is apparently not contingent on the availability of nickel.
Green rust seems similar to metal chelates used to make essential trace metals soluble so that they can be taken up systemically by plants. These are widely used in agriculture; EDTA and NTA readily take up lead and heavy metals and were used to de-lead workers in the lead industry at one time. Extractive metallurgists use LIX reagents (ion exchange) as intermediaries in smelting operations – extraction of copper for instance.