What is the process of adding CO2 to water called?

The process of adding CO2 to water is known as recarbonation. This process is commonly used in water treatment to help stabilize the pH of the water and improve the taste by adding a slight level of acidity. It can also enhance the solubility of certain minerals in the water.

In the context of water treatment, recarbonation frequently occurs after water has gone through a process that may remove the original CO2, such as lime softening. By reintroducing CO2, the treatment facility can adjust the water's chemistry to optimal levels for delivery and consumption.

Understanding recarbonation is important in the broader context of water treatment processes, as it plays a significant role in maintaining water quality and ensuring that it meets health and regulatory standards. The other options presented relate to different processes: carbonation typically refers to the addition of CO2 to beverages, dechlorination is the removal of chlorine from water, and reoxygenation involves the addition of oxygen, not carbon dioxide. Therefore, recarbonation specifically focuses on the introduction of CO2, which is crucial for effective water treatment.