World's largest pool

[mnv]

Hi,

I was quite intrigued by this treatment technology when I saw it presented. The guy doing the presentation gave us some numbers:

- total area 80 000 m2
- depth 3 m
- residence time of sea water 120 days = 2000 m3/day pumped from the sea
- maintenance costs of 20 000 $ / month = 1$/m3/year
- The pool is vacuumed every day
- he stated they used very low amounts of chlorine

The low maintenance costs strongly suggest some simple kind of treatment like Richard stated:

will be treated similar to the ocean itself

But how do they control algae growth in that huge amount of water? Even if the water coming in the pool is totally filtered there will always be algae floating or lying on the bottom of the pool.

Mario

 

[chem geek]

My best guess is that the sea water that they are using is already relatively clear, warm and does not have a lot of visible algae. Different sorts of algae will live in sea water than the far less salty regular pool environment. So only a small amount of algae control may be necessary. Possibly a polymer based algaecide like PolyQuat at lower dosage since it is also a clarifier. Or they could use a phosphate remover, but that's more expensive. The small amount of chorine helps as well. The bather load per volume of water is very low so by turning over the water every 3 months and with good filtration they don't build up anything into their lagoon that is much different than is what is already in the ocean.

I'd like to see if their technique works as well when the lagoon is connected to ocean water that isn't already as clear, is much colder, etc. Shifting away from the "natural" balance of local sea water would most likely lead to increases in algae -- that is, adding nutrients or increasing temperature. I also suspect that if the bather load were more like a regular pool, that algae control would be much more difficult due to the increased organics and ammonia introduced into the pool.

Richard

 

[mnv]

Thank you Richard for your expertise,

Just to add one more information, all the water used for recirculation with the ocean passes through an aquarium before being treated and injected into the pool. With a 2000m3/day passing through that aquarium, it doesn't even need any treatment.

This technology in the middle east will without a doubt be used everywhere, the maintenance costs are nothing compared to the added property value. Current projects that feature landscaping lagoons have huge water color and odour problems.

Mario

 

[chem geek]

Just to add one more information, all the water used for recirculation with the ocean passes through an aquarium before being treated and injected into the pool. With a 2000m3/day passing through that aquarium, it doesn't even need any treatment.

Mario,

Ah, an aquarium. I missed that part when I looked at the website. Well, waterbear knows a lot about aquariums so could shed a lot more light on how that might help filter the water and prevent algae. Hopefully he will chime in about that.

Richard

 

[mnv]

Hi again,

I think the aquarium is just a free bonus you can add to the system with no maintenance costs and not a part of the treatment process itself.

The treatment operations are performed down stream from the aquarium.

Mario