What is desalination?

Desalination is defined as the process of converting seawater or brackish water into fresh water. This process typically involves technologies such as reverse osmosis or distillation, which effectively remove the salt and other impurities, making the water suitable for human consumption and agricultural use. Given the increasing concerns about freshwater scarcity, desalination plays a critical role, especially in coastal areas where freshwater resources are limited.

In contrast, the other options describe different processes. Adding minerals to fresh water pertains to mineralization or remineralization, which is not related to desalination. Removing pollutants from surface water refers to water purification methods that target contaminants but do not involve the conversion of saline water to freshwater. Finally, filtration of groundwater through sand describes a method of treating already fresh water to improve its quality, rather than transforming seawater or brackish water into fresh water. Understanding these distinctions reinforces why the correct choice is specifically focused on the conversion aspect of desalination.