Products like this are tested against water quality standards and can probably can achieve a better performance/price ratio than what you can build yourself unless you're planning to put significant time and effort into this project.
If you're planning to build your own system for your own amusement or education, then you should first decide how pure do you want the output fresh water to be, and what is your resource (time and money) as well as energy budget?
You can buy inexpensive membranes, water pumps, and solar panels from places like AliExpress but might need to perform modifications to generate the required pressure:
2. Solar still: use mirrors to focus sunlight and evaporate water. Easy to build but only practical in climates that receive lots of sunlight, only works during daytime.
3. Electrolysis: probably not practical for filtering lots of water on a large scale because it's slow and energy-intensive, but can result in the purest water. Buy a solar panel, put positive anodes and negative cathode into the water to break it down into hydrogen and oxygen, and then wait for a long time.
Also be aware that if you store the water in a plastic barrel, certain phthalates might leach out which could be carcinogenic or interfere with your hormone system. It might be a better idea to use a stainless steel or glass container.
- https://www.survivorfilter.com/products/pro-series-virus-met...
Products like this are tested against water quality standards and can probably can achieve a better performance/price ratio than what you can build yourself unless you're planning to put significant time and effort into this project.
There are universities working on this problem as well who might already have some projects in progress such as: https://news.mit.edu/2020/passive-solar-powered-water-desali...
If you're planning to build your own system for your own amusement or education, then you should first decide how pure do you want the output fresh water to be, and what is your resource (time and money) as well as energy budget?
1. Reverse osmosis seems like the most pragmatic solution: https://en.wikipedia.org/wiki/Reverse_osmosis#Fresh_water_ap...
You can buy inexpensive membranes, water pumps, and solar panels from places like AliExpress but might need to perform modifications to generate the required pressure:
- Reverse Osmosis Membrane: https://www.aliexpress.com/item/32669709750.html - Solar-powered fountain: https://www.aliexpress.com/item/4001095938363.html
2. Solar still: use mirrors to focus sunlight and evaporate water. Easy to build but only practical in climates that receive lots of sunlight, only works during daytime.
- https://en.wikipedia.org/wiki/Solar_still
3. Electrolysis: probably not practical for filtering lots of water on a large scale because it's slow and energy-intensive, but can result in the purest water. Buy a solar panel, put positive anodes and negative cathode into the water to break it down into hydrogen and oxygen, and then wait for a long time.
- https://en.wikipedia.org/wiki/Electrolysis_of_water - https://en.wikipedia.org/wiki/Water_splitting
If you're planning to drink the water for extended periods of time, it might also be a good idea to remineralize the water:
- https://thewatergeeks.com/how-to-remineralize-ro-water/
Also be aware that if you store the water in a plastic barrel, certain phthalates might leach out which could be carcinogenic or interfere with your hormone system. It might be a better idea to use a stainless steel or glass container.
- https://www.vox.com/science-and-health/2018/9/11/17614540/pl...