Even devices that use Reverse Osmosis usually don't aim to catch all contaminants in the filter - they use a membrane/filter to separate the clean water output from a waste water stream that contains the contaminants/salts in higher concentration. This device effectively tries to replace the filter/membrane with an electrical current:
> their unit relies on a technique called ion concentration polarization (ICP), which was pioneered by Han’s group more than 10 years ago. Rather than filtering water, the ICP process applies an electrical field to membranes placed above and below a channel of water. The membranes repel positively or negatively charged particles — including salt molecules, bacteria, and viruses — as they flow past. The charged particles are funneled into a second stream of water that is eventually discharged.
From https://news.mit.edu/2022/portable-desalination-drinking-wat...:
> their unit relies on a technique called ion concentration polarization (ICP), which was pioneered by Han’s group more than 10 years ago. Rather than filtering water, the ICP process applies an electrical field to membranes placed above and below a channel of water. The membranes repel positively or negatively charged particles — including salt molecules, bacteria, and viruses — as they flow past. The charged particles are funneled into a second stream of water that is eventually discharged.