
Scientists discover cheap material that can remove mercury from water - antineutrino
http://thenewdaily.com.au/news/2015/10/20/accidental-discovery-reveals-orange-peel-saves-thousands-lives/
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dalke
The full paper is at
[http://onlinelibrary.wiley.com/doi/10.1002/anie.201508708/fu...](http://onlinelibrary.wiley.com/doi/10.1002/anie.201508708/full)
and titled 'Sulfur-Limonene Polysulfide: A Material Synthesized Entirely from
Industrial By-Products and Its Use in Removing Toxic Metals from Water and
Soil'.

> In conclusion, we have explored the properties of a polysulfide synthesized
> entirely from the industrial by-products sulfur and limonene. The
> polysulfide is easy to synthesize on a large scale and requires no exogenous
> reagents or solvents. The polysulfide removes PdII and HgII from water and
> soil and turns yellow when exposed to mercury(II). This response is
> selective for mercury, a discovery that may find use in sensing
> applications. We plan to develop the sulfur-limonene polysulfide as an
> inexpensive material for environmental remediation, where it will be used to
> sequester toxic metals from complex mixtures. More generally, this research
> is part of a growing effort to identify new and useful properties of
> materials with high sulfur content6 and to synthesize them in an efficient
> and sustainable fashion.

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cstross
If they can come up with a variant on this that is specific to arsenic, the
implications for Pakistan are _huge_.

[http://www.dawn.com/news/356241/lahore-high-arsenic-
concentr...](http://www.dawn.com/news/356241/lahore-high-arsenic-
concentration-in-potable-water-study-isposal-of-untreated-industrial-waste)

~~~
illegalsmile
If you can come up with ANY variants that remove ANY other heavy metals the
implications for EVERYWHERE are huge.

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jp555
Huh, sulpher-containing food (garlic, onion, cabbage, etc) has long been
recommended to aid in the flushing of heavy metals as it's believed that they
aggressively bind together to make much more bio-mobile compounds.

~~~
dalke
While mention of that possibility appears in the literature, the only tests I
can find are on animals, and they don't seem all that conclusive to me.

To be a useful recommendation, I would like to know the dose. That is, if the
water has a 50% higher lead concentration, how much garlic (etc.) should I eat
to mitigate the possible ill effects? Is a clove/week enough? 20 bulbs/day?

For example, if I go by
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4279617/](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4279617/)
which tests "A. sativum extract (400 mg kg-1 ..." on rodents, then that's
equivalent to someone weighing 100 kg eating 40 g of garlic. A clove is about
3 grams, so 40 grams is a bit over a head of garlic per day. Which is rather a
lot.

I would think the garlic (etc.) growers would be all over this, since if they
could convince the millions of people living in areas with high lead
concentrations to eat an extra head or two of garlic (etc.) per day, then
that's an economic boom for them.

I would also worry that it depends on the _kind_ of food. Does it exclude
Vidalia onions? What other onions should we avoid? How should they be labeled?

I also can't help but think of scurvy treatments. The British Navy first used
limes. Quoting from
[https://en.wikipedia.org/wiki/Scurvy](https://en.wikipedia.org/wiki/Scurvy) :

> West Indian limes replaced lemons because they were more easily obtained
> from Britain's Caribbean colonies[18] and were believed to be more effective
> because they were more acidic, and it was the acid, not the (then-unknown)
> Vitamin C that was believed to cure scurvy. In fact, the West Indian limes
> were significantly lower in Vitamin C than the previous lemons and further
> were not served fresh but rather as lime juice, which had been exposed to
> light and air and piped through copper tubing, all of which significantly
> reduced the Vitamin C.

That is, is it really the high sulfur in garlic (etc.) which helps, or is it
something else?

I tried to find this information, but was overwhelmed by people saying they
are traditional medicine, with pointers to others who then point to etc. I
didn't find anything like a dose/response curve, even for rodents.

~~~
logfromblammo
Well, the sulfur-limonene polysulfide compound worked on mercury (Hg) and
palladium (Pd). So if you want to use it to remove lead (Pb), you might have
to add dyslexide as a side-group to the polymer.~

EDTA will chelate almost any positively charged metal ion in the body,
including arsenic and lead, but will also grab stuff like iron, zinc, calcium,
and magnesium, which are rather important to keep. EDTA has two amine ligands
and four carboxylic acid ligands. But the metals you really want to get rid of
--like lead, mercury, cadmium, and arsenic--are attracted to amine, thiolate,
and sulfhydryl groups.

So peptides containing multiple cysteine groups are often used in biology to
bind and transport toxic heavy metals. Methionine, as another sulfur-
containing amino acid, is also useful. So N-acetylcysteine and
S-adenosylmethionine help clear heavy metals from the body without also
sucking out the metals you would prefer to keep. If you can come up with a
better, more selective chelation agent, you're likely to get a few prestigious
prizes.

I don't think eating enormous quantities of garlic is likely to be a great
solution. I'd probably just go with a N-acetylcysteine supplement--which also
has the beneficial side effect of helping with hangovers--and use lead testing
strips (if red, there's lead) to avoid chronic exposure. Also, no allium-
halitosis.

Vidalia onions are mild and sweet because they are grown in low-sulfur soil.
Tangy, pungent onions are the ones that will have higher levels of
organosulfur compounds, so they're the ones you want if you're worried about
heavy metals poisoning.

But then again, those organosulfur compounds can also help carry heavy metals
_into_ your body, so if the onions are grown in high-sulfur, high-arsenic
soil, for instance, you're probably just making things worse.

~~~
abakker
I'm curious if this is common knowledge or not. A quick look at the wikipedia
page for acetylcystine does not mention using it as a chelating agent,
although it does seem to have a variety of other uses. Is this an oversight of
the Wikipedia editors, or is this not a common recommendation?

~~~
logfromblammo
It doesn't work very well by itself as a chelating agent. But it does have an
amine group and a thiol group, and can form complexes with heavier metals.
Having only two ligands, that aren't positioned very advantageously relative
to each other, it just doesn't "stick" very well.

It's primary usefulness would be to replace the raw materials that the body
uses to make the larger peptide molecules that it uses to detoxify heavy
metals. Most of these require cysteine or glutathione, for the thiol.

I think NAC is mostly known to broscience as a hangover remedy, as it helps
clear acetaldehyde in the liver.

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ChuckMcM
That's a useful result, I jokingly thought they were going to say Tuna since
its been such a challenge in the Pacific. The next step I suppose would be to
turn this stuff out in bulk and line drain pipes to see how well it works
passively?

I didn't pick up if it was reversible, do you discard it after it has become
saturated?

