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Home-Brew water purification unit Answered

Lately I've been looking into home water purification; and I was hoping I could get some community support, and ideas :)

So far in my online research, I have found that active carbon works well as a filter. So, I was thinking I could sew some between two pieces of fabric, and then put it at the bottom of a pvc pipe, thus letting the water go through it;
From there, I got the idea of making a wooden box, which will be just about (1 ft x 1 ft) all the way around. I'd also line the inside with a plastic sheet, like those found in a home pond. I think that would make a good housing for the filtering equipment;

I'm still working out the details on the actual purification of the water; I have a basic understanding of it, though if you have some insight, please do share :)

Also, if active carbon would be a good solution, where would be a good place to find it; I live in the Glendale, Arizona area, so somewhere around here, if you could.


There are several (potential) contaminants that you want your filter to remove:
Chemical (can include dissolved salts, pesticides, heavy metals and other stuff depending where you get your water from), Microbial (generally only applicable if you get water from a natural source or an open storage area) and Particulates (debris of all shapes and sizes).

The method you use to purify water depends heavily on how contaminated your water is, the specific things contaminating it and the volume you want to purify. Active carbon is an absorbant that can capture certain chemicals in its structure but it can also function as a microfilter depending on how well you channel the flow.

For example say you have a well bringing up relatively clean water slowly and continuously into a closed storage unit for consumption. For a homebrew filter I would suggest something like a coarse filter (like a metallic mesh or a pebble bank), a fine filter (such as cloth or a sand bank), a long circuitous path in transparent tubing (UV sterilisation with sunlight), then your active carbon filter (like you wrote: make a cartridge with active carbon in cloth and insert that in the pipeline). Of course a commercial unit will generally provide a better (or at least a more predictable) purification.

Active carbon can be made from regular charcoal but don't ask me how (should be easy enough to google). Otherwise you should be able to buy it at pet stores which use active carbon for aquarium filters.

You're welcome. I'm an engineer so when I get started on these kind of things I tend to rattle on ;)

Keep in mind that if you suspect that water is contaminated you really should have it analysed at a laboratory or something. This will help you design the best system to clean it. Also a good idea is to have it analysed after installing the purifier to make sure it is safe for consumption.

Well, the water I will be using will be from tap. A friend of mine has heard that there are many unwanted additives in it, and he wants me to work on making him a water purification unit.

So, it's not like the water will be extensively dirty; but he just wants to use this as an extra health safety precaution, which is understandable.

in that case you can ignore pretty much everything I had said before :P

Active carbon should be enough.

. Activated Carbon is one of the best general-purpose media for chemical removal and it will probably do the job, but, as noted earlier, you really need to know what the contaminant(s) is (are) before selecting the media. AC will remove many organic compounds, but it doesn't handle inorganics, metals, &c very well.

As NachoMahma said, depends on the metals and I would add that it also depends on the concentration of the impurities. AC can handle small amounts of metals ( I dont know which off the top of my head). Extreme cases you are looking at chemical flocculation or some micro-organism that consumes the stuff. Neither is something you could reasonably expect to do at home nor should it be necessary for tap water (these steps are usually done in large scale water treatment plants for cities).

I don't know where you live but tap water is generally safe to drink right out of the tap, so AC might give a slight purity boost but I don't think much more is needed.

I live in Glendale, Arizona; the home which will be using the unit is in Peoria, because a friend wants me to build it for him.
There seemed to be a certain metal that he wanted out of his water. Although, I don't remember which it was.. It has been awhile since I've discussed it with him.

. Depends on which metal or metallic compound you are talking about. Google is your friend.