Salt is removed from the ocean through both natural processes and human intervention. Naturally, some salt is removed by organisms using it in their biological processes. Additionally, hydrothermal vents remove some salts while adding others. The long-term balance, however, results in a net accumulation of salt in the ocean.
Human methods primarily focus on desalination, crucial for providing fresh water. Two prominent techniques are:
Desalination Techniques:
1. Thermal Distillation:
This method uses heat to boil seawater, turning it into vapor. The salt is left behind, and the vapor is then cooled and condensed back into fresh water.
2. Reverse Osmosis:
This more common technique uses pressure to force seawater through a special membrane. This semipermeable membrane allows water molecules to pass through but blocks the salt ions, effectively separating them.
Natural Salt Removal Processes:
- Biological Uptake: Marine organisms utilize some dissolved salts, removing them from the water.
- Hydrothermal Vents: These geological features interact with seawater, impacting salinity through the removal and addition of various salts.
While these natural processes occur, they don't offset the continuous influx of salt from rivers and other sources. Human desalination methods play a critical role in providing fresh water, but they are energy-intensive and can have environmental impacts.
