UV for chlorine removal, Anyone?

[DaveB]

Anyone thought about UV as a means of removing chlorine from tap water and if so what units would you recommend . I appreciate that you would need to change the UV bulb but I seem to be changing filter cartridges far too often. Any thoughts on this would be appreciated.

[Duncan]

ill certainly look into this for you Dave

dunc

[DaveB]

Something to get your teeth into Duncan.

[Manky Sanke]

Chlorinated water, exposed to aeration and sunlight has a half life of about three hours which is why aeration can reduce a typical tap water level of chlorine to negligible proportions in a few hours. The chloramine half life under the same conditions is about 12 days. A standard UV will accelerate the rate at which both will decompose but, unless you use a very high power UV, you would have to expose water to the radiation for unrealistic periods especially if it had chloramine in it.

[DaveB]

Chlorinated water, exposed to aeration and sunlight has a half life of about three hours which is why aeration can reduce a typical tap water level of chlorine to negligible proportions in a few hours. The chloramine half life under the same conditions is about 12 days. A standard UV will accelerate the rate at which both will decompose but, unless you use a very high power UV, you would have to expose water to the radiation for unrealistic periods especially if it had chloramine in it.

What sort of power are we talking about and Is it not cost effective to have water slowly trickling through a unit. Do they not make domestic units which would work?

[Manky Sanke]

I don't know the cost because I've never considered that as a method of dechlorination before but my gut feeling is that, with the initial set up cost and the replacement cost of high power UV bulbs, in order to obtain a flow rate similar to an activated carbon canister, it wouldn't be a cheaper method. There would also be the problem of a tube/equipment failure or a power outage leading to dumping undechlorinated water straight into the pond. Fail safe control equipment could be designed to protect against these risks, I could do that quite easily, but this would only increase the initial set up and running cost.

I have far too many projects at the moment to have time to investigate this idea but, if you and/or Duncan want to look for suitable UV equipment I would be interested in what you find.

[DaveB]

Cheers Sid for your thoughts on this and appreciate what you have said. I will look into this a bit more myself and see what I can find. I will then post this and see what Duncan and yourself think.