Wednesday, February 01, 2012

germicidal use for solar concentrators?

Respected Sir, Hope you will be fine. I am a university student in Turkey and doing MS Environmental Engineering. I am interested in designing and application of Concentrator Parabolic Panels as a reactor in waste water treatment. In this technology my basic purpose will be to use UV portion of sun light in degradation of water pollutants. I need your kind guidance in this project. Please guide me with what strategy I should precede and which areas are still needed to be studied, improved or discovered on which an academic research should be carried on.

Waiting for kind response..
Best Regards
Muhammad T
Fatih University Istanbul Turkey.

Hello Muhammad and thank you for writing to me.

I had thought also about using UV in concentrated sunlight for such a purpose. I am interested in your ideas about this.

The big problem is that the UV required for germicidal irradiation is UV-C (100-290 nm). According to the US EPA:[UV-C is] completely absorbed by the ozone layer and atmosphere. This is a good thing for us humans. There is such a small amount that even when concentrated, it may not be effective. Even at the concentration of my parabolic trough solar concentrator (about 18:1), the heat produced from the rest of the spectrum might boil the water before any UV-C sterilizes the microorganisms?

The glass of the reactor must be of a type clear to UV-C (quartz glass).

The water to be treated must already be very clear since particulates shield the UV-C. The water must be filtered to a high level (reverse osmosis?) before irradiation.

A correct exposure time must be determined for the radiation to be effective.

Successful operation of the system needs a test that the organisms are sterile and cannot reproduce since the UV-C does not kill them. Looking with a microscope, they will still be moving.

Do you plan to build a model?

Would boiling or distilling the water with concentrated sunlight be a better project? There is much heat available this way which can effectively kill all organisms, even in sludge. The UV-C is difficult.

George Plhak

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