Posted on 11/23/2011 8:23:02 PM PST by djf
No, not directly. There are waste products in there that don’t break down without being filtered out.
It’s better to set up a simple dirt/sand layer filter system and then bottle the filtered liquid and put it in the sun. Anything you can do to filter out unwanted material first, the better.
Wouldn’t advise this if someone had std’s like herpes, or aids or hepatitis strains like b or c.
I’m intrigued by the possibility of a parabolic cooker/still. All you need is relatively stiff paper (almost cardboard stiff but not quite).
Cover with aluminum foil, shiny side up, and rill it into a cone shape. Cut a hole in the bottom and it will focus the sunlight.
Ever use a magnifying glass and shine the sun on an ant? Same deal here. Concentrates the sunlight possibly hundreds of times! DO NOT stick your hand in the opening!!
Giardia is big though (relatively speaking) and is able to be trapped in microfilters.
Don’t believe it can survive UV disinfection.
You could always use a pressure cooker to get the water up to a higher temperature.
The big problem out here in western states is natural occurring arsenic The method effectiveness also a depends on the water’s turbid. When the water is highly turbid, SODIS can not be used alone, additional filtering or flocculation is then necessary to clarify the water prior to SODIS treatment.
I would consider this method for use with rain collected water, springs or water from fast moving streams and brooks with a very low turbid. For example the major source (and almost the only sure year round source) of water here is the river which is filled with all sorts of debris and possible chemicals and so I would not use this method. If I made up into the mountains a hour north are a number of springs and fast running creeks that this method would be sufficient for.
But a good filtering system is usable for just about any water you can find, Nothing wrong with having multiple ‘tools’ in your ‘tool box’ I just wouldn’t depend on this sytem as my primary means of purifying water.
Could one make a filter by using fine sand in layers of coffee filters?
There are all kinds of approaches that are cost effective.
Solar still can be a rectangular box black on all sides but one of the big sides is glass or plastic; this side faces up towards the sun. It has to sit at an angle and have black cloth or something to have water seep slowly down the bottom of the inside of the box where the sun’s rays heat it. It runs down the inside of the glass/plastic after it condenses on it, collect it at the bottom.
I’m conservative, but I’m not “against” using solar, wind, etc., power. I’m simply “against” setting up financial scams and ripoffs where the particular usage of solar, etc. power makes no economic sense.
People who have zero enginneering or manufacturing experience often fall prey to scams based on “belief” in some junk science. One of the big areas that people with not much experience completely forget or have no concept of is maintenance. Such as the case with the aging windmills we have that are proving too expensive to maintain.
Yes, however the can system would be small and take a long time to produce a decent amount of water. You want the layers not to leech over into other layers. Thin cotton cloth or cheesecloth can be cut to work with larger buckets.
But I’d start with a layer of good soil. Then small pea gravel. Then work into finer layers.
Periodically you need to change out the soil layer. Eventually you’ll need to redo all the layers.
If you wanted to make this more antibacterial some people make a layer of silver coins in between a couple fine sand layers.
I can’t help but remember how I grew up. My grandparents had a cistern made of stone all the way down in the ground. They caught rain water from the roof and filtered it through a flour sack. We never got sick or knew anything about bacteria in the water. There was an occasional little bug that resembled an earwig in the water, but we just threw him out of the dipper and drank the water. When it didn’t rain for a spell and the cistern went dry, Pa would hitch up the horses to the wagon, put the rain barrels on it, and drive a mile to the creek where there was a spring. We dipped spring water into the barrels and filled some water jugs for drinking. Life on a dry hillside was not easy, but joyful.
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