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Comment by wppick | Hacker News Reader

Reverse osmosis is the next goldmine opportunity. Every home will likely need one, or maybe there will be neighbourhood nodes. It's even good for getting clean drinking water from salt water.

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I am in Thailand where the tap water is considered undrinkable.

Just this morning I went to the neighbourhood Reverse osmosis machine and paid a few cents to fill up my drinking water bottles.

I think it's a great system.

In India, we got water from groundwater, which was over polluted with minerals, so we bought an RO filter. It's basically a must there, and all the other houses I visited there had one. If we don't fix water pollution here, we will have a similar situation on our hands.

Reverse osmosis is wasteful. The next goldmine is atmospheric water generation. The atmosphere is the largest untapped reservoir of clean water on Earth, and mother nature has already desalinated the water through evaporation. Far less energy intensive and wasteful to condense the atmosphere than clean water by R.O.

If you want clean water, you need to do more than evaporate it. Thanks to nasty stuff like Atrazine and PFAS, our rainwater brings chemicals that can alter reproductive organs, endocrine function, and are linked to cancer. I don't know if reverse osmosis removes these chemicals, but it would be worth removing at the source. An ounce of prevention can save a pound of downstream medical and societal costs.

https://www.panna.org/resources/atrazine#2

https://www.theguardian.com/environment/2019/dec/17/rainwate...

https://www.ewg.org/research/ewg-proposes-pfas-standards-ful...

Our greywater too (from oral contraceptives)

Changing state from gas to liquid sounds pretty energy intensive to me. Do you have numbers for your claim that it's less energy intensive than RO?

I’d like to see numbers too, but the gas is a higher energy state and so its not outlandish to imagine there might be a way to bring it down efficiently.

> wasteful

Are you referring to the resources used to create the equipment then discard it when it's done? Or to the wasted water? A permeate pump increases efficiency quite a bit.

Atmospheric water collection will have contamination problems with volatiles and aerosols. Unusable in polluted cities. Unless you filter and clean, but you're back to the initial problem...

What would the water treatment for rainwater look like?

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