Closed-loop water supply system... Could it work??

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margo - newbie
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Closed-loop water supply system... Could it work??

Post: # 166564Post Nome
Tue Sep 01, 2009 11:38 pm

So I got looking at natural swimming pools the other day, like this: ... mmingpools

and this

and I got thinking...

Suppose my dream-home and eco-campsite sent all its greywater to a series of reed beds...
And suppose the final reed bed overflowed into a natural swimming pool like this, where the plant filtration system keeps the water good enough to drink...
And suppose the swimming pool also acted as a water storage tank, to supply the beginning of the chain all over again (via a pump, a tank at the house/shower block, and a final UV filter to ensure water was potable). The pool would hopefully be large enough to absorb fluctuations in water level without affecting its performance, thus keeping the fresh tanks fully stocked and continuing to receive cleaned water from the reed beds.
Of course, no water system could ever be 100% closed-loop - but evaporation would be offset by rainwater harvesting from the buidlings on site.

And how about this? Between the last reed bed and the pool (and if the lie of the land allows), channel water into a narrow stream and stick in a water wheel for electricity generation.

(I have no hands-on experience of reed beds, or water wheels, or pumps, or natural swimming pools - I just read a lot.)

Anyone care to comment? Would this be possible?

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Re: Closed-loop water supply system... Could it work??

Post: # 166594Post Odsox
Wed Sep 02, 2009 8:09 am

Can't comment on your water quality, but regarding your proposed hydro-electric system, I don't think you would have sufficient flow to be feasible.
I have a graph for heads and flow rates and the minimum is for a head (drop) of 3 metres and a flow rate of 20 litres per second, and that would generate 20 watts. To get a Kilowatt you would need a head of 30 metres and a flow rate of 75 litres per second, or a head of 100m and flow of 30 l/s.
Now, if you had a mountain stream ..... :wink:

Disclaimer: I almost certainly haven't a clue what I'm talking about.

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Re: Closed-loop water supply system... Could it work??

Post: # 166705Post pumpy
Wed Sep 02, 2009 7:13 pm

hi Nome, what you suggest, on the surface, (no pun intended), seems like a cracking idea..... but i can see various pit-falls. I assume you are U.K. based, where water quality regulations are very strict, especially for commercial useage (campsite)....... also you would require a licence (no doubt). Also, if this system will be "open-air",then you have to consider contamination from other sources......; bird-poo, dead vermin, etc. Under these circumstances it would very difficult to maintain a potable supply........ it could be done with a final filtration system, but t'would be ruddy expensive. Apart from that, good luck!
it's either one or the other, or neither of the two.

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Re: Closed-loop water supply system... Could it work??

Post: # 166709Post grahamhobbs
Wed Sep 02, 2009 7:29 pm

Cut out drinking water from the loop and it works, fairly standard technology these days. Oh and forget the generating of electricity, you are circulating the water with a pump, you can't expect to regenerate the electricity to work the pump now can you?

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