Modern desalinators use a process called reverse osmosis to remove salt and other impurities from seawater. Reverse osmosis is a pressure-driven process that forces water through a semipermeable membrane, leaving behind the salt and other contaminants.

Here's a simplified explanation of how a modern desalinator works:

1. Pretreatment: Seawater is first passed through a series of filters to remove any sediment or suspended solids. This pretreatment step is important to prevent damage to the desalination membranes.

2. High-pressure pump: The pretreated seawater is then pumped at high pressure through a series of semipermeable membranes. These membranes have very tiny pores that allow water molecules to pass through, but they block the passage of salt and other impurities.

3. Separation: As the high-pressure seawater passes through the membranes, the salt and other impurities are trapped on the membrane surface. The purified water, which is now free of salt, is collected on the other side of the membrane.

4. Post-treatment: The desalinated water may undergo further treatment, such as disinfection and pH adjustment, to make it safe for drinking or other uses.

Modern desalinators are highly efficient and can produce large quantities of fresh water from seawater. They are an important technology for providing clean water in areas with limited freshwater resources.