LED Water Purifier

I was walking through my local camping supply store the other day when I came across this water purifier that cost $50 (I know outrageous) Being the DIYer I am I took a closer look at it to find that it was simply Some UV lights. Then it hit me, I can make this way cheaper. So I did.

HINT: start your soldering iron and hot glue gun now so they warm up

Step 1 What you will need

Here is a list of all the tools and parts you will need.

PARTS

- some ultraviolet LEDs, I used 4

-A small switch

-One resistor for each LED, Mine were 330 ohm

-Black tape/ Electrical tape

-Some wire

-Small plastic or glass container, This should be watertight and clear

-A battery, Mine was a 7.2 volt RC car battery

TOOLS

-Solder Iron

-Solder

-Wire cutters/ strippers

-Hot glue gun with hot glue

-Scissors

I had some stuff but I had to buy the LEDs ($2 Each) and the switch ($1 for a pack of 5)

Comments

[brentonl]

So, you claim that the water will be 99.99% bacteria free.  Have you tested that hypothesis with bacterial cultures?

[SpiroExDeus]

Surely the LEDs do not need to actually be IN the water. So long as the container doesn't filter UV light you could surely put the UV LEDs OUTSIDE the container.

Would be interesting to test this with proper cultures on petri dishes. Shame I don't have a lab / money / the scientific experience to do it...

[Algag]

*drum roll* http://www.thinkgeek.com/geek-kids/7-13-years/bd73/
TA DA

[SpiroExDeus]

:( May not have been the case when you posted that link but it's now showing as 'out of stock'

[MadMan.inc]

found manufacturer uv diodes with 240nM wavelength

http://www.cardonalabs.com/UVLEDs.html

[chamunks]

You'd need to buy 1 million of these before they would be cheap enough to be worth it from these people.

[gcc_mtl]

Your device does not kill bacteria:

1 - UVC is germicidal, thats between 100 and 280nM
2 - most plastics and glass filter out UV light

You need to use Clear poly-styrene plastic or cobalt glass for UVC to pass through, or stick the bulbs into the water without anything infront of them.

[elting]

i made one with a solar panel and baby food jar.i put it into my small platic pond and within 2 days the amount of green crap was cut in half.i wish i would of looked here first befor i went of the trouble of figureing it out myself.well thats the fun in it any way.nice diy

[Strycn1n3]

it kills the bacteria sure but some water would still taste like S***

[tweakinreaper]

I think heat shrink tubing would be easier to put on. Dab each end of tubing with hot glue if worried about water penetration.

[ego73]

If it does indeed nuke 99.99%, how awesome would it be to rig it for solar/rechargeable battery operation! Then rig it, all nice n compact, onto a cap for a 2 gallon plastic container. Cool!

[safedrinkingwater]

I can't find anything below 350nm! I've been looking at combining a UV-C water treatment (including sand filter) with DIY PV solar panels for a project in Cameroon (remote schools).
I understand UV-C LEDS will cost more but would like to get hold of some to develope the idea with a view that the price will come down eventually. Anyone know where i can get some?
I wouldn't have thought the 400nm LEDS used in this design actually have any effect? Maybe someone could test using a coliform presence test? fairly cheap to buy. I got some for £3.50 ($7?).

[varun2021]

could you tell me how much current each of the uv led was consuming?

[findoggydog]

In some, if not all cases the UV light will be neutralised by the small container housing the light, therefore rendering it useless for the purpose outlined.

The danger of that is you will think your water is being purified, when it is actually no different than when you put it in the bottle.

But unless you have a bio-lab at hand there will be no way of knowing.

Personally I'm going to stick with the store-bought purifiers as they get thoroughly tested - I don't want gastro in the middle of no where.

[n33r]

cant u solder em in series connection it would much easier to handle

[Pie Ninja]

You're silly.

[Nyxius]

Where did you get your UV diodes from?

[nrepak]

electric goldmine for the 400s look around for some 240nm ones they will set you back but work a lot better try an auction site to get them cheaper

[Nyxius]

Thanks man!

[vatak]

UV-c LEDs are the best for this application.

[jigoku13]

 where can i buy those uv c LED's?? is there any site exist that sell those kind of diodes????

[jigoku13]

where did you find your uv diodes with 240nM wavelength? what site can i find one of those diodes?  pls suggest some. . .

[mossimo3]

This is an interesting concept, however only UV-C is effective in killing harmful bacteria. But the down-side is UV-C is harmful to your eyes and skin; it can give your skin and eyes, yes EYES too, a nasty burn. So if you manage to find UV-C LEDs, you should enclose them in an opaque container--As should be done with any UV LEDs. Other than that this is a neat idea! Have you tried adding an external power supply or something to have 'unlimited' power for however long you want to purify your water?

[manutea]

Nice job-thank you !

[xiuxiubaby]

hoho it's so cool

[phenoptix]

What wavelength were the UV LEDs? I heard about this as an application for low wavelength UV LEDs, I wouldn't think the UV LEDs I sell that are around 400nm wavelength would be powerful enough (too long a wavelength) to cause the bacteria any harm - which is a shame!

[nrepak]

Ahh good point. I bought two different packages one had 240nM and the other had 450 nm but I mixed them up and am not sure which ones I used. Thanks for reminding me

[phenoptix]

the 240nm are the real bad boys! how much did they set you back? The 450 would be a blue colour

[Kyle_S]

I remember looking this up once _after_ ordering a bag of 12 cheap UV leds for $5. Worthless for sanitation, pretty cool for other things (I'm building a ring light out of mine now, at least it'll look cool) The low nm uv leds are in the range of $50 if you're lucky. That said you can find gemacidal uv lamps online for under $20, some of them under $10! Sure the driver circuitry will be different, but you can still do this very cheaply.

[crc09]

this is incredable, great for camping or survival

[Wolf Seril]

If I'm stranded in the woods near some suspect-looking water and all I have is several UV LEDs, solder, a power source, and some plastic containers, I'll be sure to keep this in mind. Just kidding, nice instructable.

[vapoking]

Isn't the wavelength that fries bugs bad to look at? a book on constructing a mushroom lab advised that if you use uv for sterilization you should set up the room so that the lights go off when the door opens.

[nrepak]

any UV light is bad to look directly at and not rie about the shroom lab lol

[nrepak]

Woops typo thats sposed to say and not sure about the shroom lab

[jonathan95123]

i dont think thats the right UV light for the job.. like vatak says, UV-c is the best, and i believe this LED mostly puts out UV-a ..... but good idea, dont think i would need to build one of these, i did use an UV LED to make some water glow after i dumped a broken highlighter into it. i just have the waterbottle sitting on my desk and i turn on the UV LED when friends are over or sometimes at night.

[dark sponge]

Judging by the color, this isn't the right frequency. This is about the color af my 390nm UV leds. You need a much higher frequency light to kill bacteria and stuff. And even if this was the right frequency, this wouldn't filter out toxins in the water. At least it makes the water glow a cool color!

[Mr. Grumpus]

Now if we can get some spec's on the output of the LED's in the Store purifier to compare with the homegrown one, we'll be in bidness.

Feelin some "Blade Runner" kickin in....

..."Enhance"...String of UV LED's in PVC or Clear pipe of similar diameter with regulated water flow to allow for 30-60 sec of exposure to UV light....

..."Enhance"...Utilize Solar Panels or Wind Generators for power supply...

..."Enhance"...Add rain fed cistern, some sort of pre-filter to clear out the chunkies, use gravity to power most of the water flow, and some not-so-subtle electronic wizardry to turn the system intake water valve "OFF" when power from batteries to UV LED's drops below a certain limit, leaving enough lag time to purify that which is left in the system.

Viola...or, small cello...You now have a higher tech, more pure, more nature-friendly* system of water purification/reclamation.