UV water treatment materials

[sonya]

I'm working on a UV water treatment system for household use in developing countries. I'd like to use a material that's super reflective to UV light, cheap and available in Africa. The more reflective it is, the more light will bounce off the walls and back into the water instead of being absorbed by the reactor walls. I'm currently using aluminum, but I'd like to hear if anyone has other ideas for materials to test.
Thanks!

[Marky]

Hi and welcome to the forum. Aluminum will only work for a short period of time. When designing lasers our engineers would use the alum as a substrate and make custom reflectors. They went over the alum exposed to UV. We used a company that makes the reflectors used in flashlights.

I'm not sure what country you are writing from. I would talk to some companies in the reflective metals industry....discuss your requirements including cost.

Good Luck...sounds like a great project to help a lot of people.

[sonya]

Thanks so much for your reply. Why will aluminum only work for a short period? (and how short is "short"?) I'm new to all this and don't know much about it...
Do you have ideas for specific companies I could contact? (I'm writing from Colorado.) I'm hesitant about custom reflectors, as they tend to be expensive.
I found this graph on Wikipedia: http://en.wikipedia.org/wiki/File:Image-Metal-reflectance.png
Aluminum seems to be the cheapest that will work with UV wavelengths. Of course, this is only a small comparison. I wish I could find something similar for more metals.

Thanks again!

[Marky]

Hi Sonya,

You maybe right about cost of a custom reflector. What we found with bare alum. is that it would oxidize over time...finish would get dull and hazy. Time varied...but when we saw the laser energy diminish it was the reflectors oxidizing.

Before we went to custom reflectors we had plated the reflectors with Electroless Nickel .0003"-.0005" thick.
Below is data on E/N plating and plating house in Colorado.
http://epner.com/default/index.cfm/processes-and-products/electroless-nickel/
http://www.astfinishing.com/electroless-nickel.html

I would test both plated and unplated parts...just to see if there is any difference with losses.

Email me directly if you'd like. It will be easier to help you. If you have pics that would be great.

Mark

[Harry Potterish]

Hi friends,

Thank you for your valuable thought and sharing this topic, Water quality is becoming an increasingly important issue in the US and around the world, Pollution of both ground water and surface water has resulted from the disposal of pharmaceuticals, personal care products and industrial wastes into our water supplies, Often the contaminants are found in low concentrations and are very difficult to remove by conventional means.

Nice to meet you
Harry Potterish