What does a skimmer remove?

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Anonymous

Guest
So?

I'd be kind of interested in hearing what it REALLY removes and what it won't. Does anyone know or are they magic
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A

Anonymous

Guest
I don't know for sure, but it smells like @$$.

Just kidding. I tried to convince Craig Bingham to do a little analysis of skimmate but he basically said it was on his list of things to do in the future. Probably, it varies depending on the type and quality of the skimmer. Most likely it is everything from peptides to microscopic/small macroscopic organisms. The real debate is in the degree of export of trace elements, assuming they aren't going into the stationary biomass of the tank.

Anyway, to answer your question, you would need to look at it with a microscope, run an SDS gel on it, and do elemental analysis. The first two things are fairly cheap (assuming you have access to a biochem lab, which I unfortunately don't at the moment). The last thing however is somewhat expensive if I remember correctly, which is probably why I had difficulty trying to convince Dr. Bingham to do it.

Hope that helps.
 
A

Anonymous

Guest
MFisher:

Skimmers will remove hydrophobic organics, partially hydrophobic organics, and metals that may be chelated to these organics. This includes certain proteins, carbohydrates, and lipids (and mixed molecules thereof). It also includes iron, copper, and some other metals. It does not include iodide, or iodate, and does not include all organics.

However, it should also take out any partially hydrophobic creatures (bacteria, algae, etc). Inside of these creatures will be a host of other things, which will include organics, metals, and also possibly forms of iodine.

Thus, a wide range of things are removed.

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Randy Holmes-Farley
 
A

Anonymous

Guest
theoretically speaking....

The first WATER foam fractioners were designed for use in waste water treatment. The idea is that organics will stick to the bubbles and rise up out of solution. Theoretically, you could skim a system for a LONG time and eventually remove everything except the H2O. this would be an interesting experiment


hope it helps!

vigg aka goby.

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A

Anonymous

Guest
Vigg:

You can only remove those things which absorb at the air/water interface. This is an area which has been studied far longer than skimmers or even the waste water treatment that you point out.

Many things, including some organics and almost all salts do not. Thus they cannot be removed, regardless of the skimmer type, size, or time running.

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Randy Holmes-Farley
 
A

Anonymous

Guest
randy,

sure, it was first used to sepearte ore's in the mining process in the early 1900's.. I am well versed in the technology and history of skimmers (and their ancient relatives) but have to question why you think that they will not remove salt? I thought it was fairly common knowledge that they can and will remove salt from a system.

vigg aka goby.

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A

Anonymous

Guest
They remove some water, and in that water will be salt. They cannot remove more salt than is in the water that is removed (except for a few stray ions that may be the counter ion to charged organics or chelates).

Thus, a skimmer in normal operation cannot lead to a reduced salinity.

The reason is that salts do not absorb at the air/water interface. In fact, most are repelled from this interface. They simply cannot be skimmed out.

In terms of history, I was referring to the study of the absorption of oranics at the air/water interface, which was first quantified by Ben Franklin in the 1700's.

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Randy Holmes-Farley


[This message has been edited by Randy Holmes-Farley (edited 31 January 2000).]
 
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