Microscopic membrane filters (1 Viewer)

[wind]

Nope. Atoms and dissolved ions can't be filtered out by MM.


Edit: Actually, they can. Nanofiltration membranes have special coatings that can remove some heavy metal ions and large molecules.

 

[persephone]

"Micro-filtration removes protozoans, bacteria, colloids, some colouration and some viruses."

this is from someone's notes i downloaded...does it help any of you?

 

[lucyinthehole]

Nope. Atoms and dissolved ions can't be filtered out by MM.


Edit: Actually, they can. Nanofiltration membranes have special coatings that can remove some heavy metal ions and large molecules.

lol, your answer just summarised the whole thread. both yes and no. i'm gonna go with the yes then?

 

[wind]

And yes they do

 

[persephone]

so what is the answer then?

 

[helper]

The answer is they can. This is how desalination of drinking water is done with reverse osmosis membrane filters.

Anyone who wants to argue. Please contact Vivky Chenn at the UNESCO centre for membrane technology at the university of nsw.

http://www.ceic.unsw.edu.au/staff/Vicki_Chen/memtech.htm

 

[Knives]

Seems like there are some things man's jsut not meant to know!

 

[CM_Tutor]

Microscopic membrane filters DO NOT filter out dissolved ions - ions will pass straight through them. They DO filter out large particulates, bacteria, etc.

Yes, reverse osmosis can be used to filter out ions, but simple microscopic membane filters do not do this job.

Yes, in the industrial elective, membranes that filter out ions are discussed. Again, these are not the simple membrane filters of this HSC topic.

 

[helper]

This one of the points that the board needs to clear up.
According to a number of sites including the CSU site that the board sponsors includes reverse osmosis in microscopic filters in this point.

Best bet is if they ask to mention both types.

 

[PyRo999]

my uncle just happens to be head chemical engineer at the hunter water board, and he says u can filter ANYTHING out with use of nanofiltration and reverse osmosis, so there u go

 

[Tangent]

they do filter some ions and atoms

"•Semi-permeable membranes used in reverse osmosis are either made of cellulose acetate or a layer of polyamide attached to another polymer. Under pressure these polymers allow the passage of water molecules but not that of most atoms, ions or other molecules. "
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