1. The problem asks to identify the process that separates salt from water to make it suitable for human consumption or irrigation. 2. The key concept here is the removal of salt from water, which is commonly known as desalination. 3. Desalination is the process of removing salt and other impurities from seawater or brackish water to produce fresh water. 4. This process is essential for providing potable water in areas where freshwater is scarce. 5. Therefore, the correct answer is **desalination**.