Question:
I have a Katadyn Pocket filter, which filters sediment and bugs from waterquite well, however it is not not designed to purify dissolved chemicals.I'm looking around for a portable item or a method of doing this task (in acamping environment) and I'd be grateful for any tips....

Answer: There is no filter that can remove chemical contamination. None.Anywhere.

Filters with a carbon element can reduce your exposure to somechemical contaminants, but they will not make poisonous water safe.

To purify chemically contaminated water, you have to go to reverseosmosis systems, which are orders of magnitude more expensive thanyour Katadyn filter and not suitable for hiking/backpacking, even therelatively small units made for life rafts.

Considering a reverse-osmosis filter is simply a semi-porous membrane,how do you suppose they can filter out dissolved chemicals? None of themanufacturers make this claim, although they typically include othercomponents for this purpose.

Perhaps you should study reverse osmosis systems a bit more, and gainsome more understanding. They remove chemicals. I do not know thatthey remove all of all chemicals, but they do remove enough to makesome poisonous water safe to drink.

I am speaking of real reverse osmosis systems such as are used forlife rafts and for seagoing small boats, not the kitchen devices soldat Wal-mart.

So mechanical filters will not block ANY dissolved chemicals, but onetype - the membrane in a reverse-osmosis system - will block chlorideions. So is sodium chloride NOT a chemical, or are the pores of themembrane NOT filter holes, or has a wizard put a magical spell on theprocess?

You need to outline your story before you start typing, Jim. I won'targue against nonsense - it stands alone.