Most sources on the internet state that ozonation water treatment dates back to the 1800s. The truth is that ozonation could only take place once electricity was discovered, so ozonation as a water treatment method wasn’t studied until the 1840s. The most basic ozonation system includes a transformer, circuit, and water. Take caution if you purchase or own such devices as ozone causes lung damage, and beware that water and electricity are a deadly combination.
This isn’t my most favorite method of purifying water, but it works. People complain that this method uses too much energy to be efficient, but in places like California where there is never-ending drought but a continuous supply of salt water, DIY desalination might start to become more commonplace. To paraphrase the method from WikiHow, I rewrote the steps to making your own water from salt water:
Pour your salt water into a bowl.
Place a cup in the bowl.
Thoroughly cover the bowl with plastic wrap.
Place the setup in a sunny spot.
This method takes an estimated three to four hours to produce about a quarter of a liter of water. Here is a video of the DIY salt water purifier in action.