What is one of the important effects of aeration on dissolved gases?

Aeration plays a significant role in managing the concentrations of dissolved gases in water. When water is aerated, it is brought into contact with air, which enhances the exchange of gases. One of the critical effects of this process is that it decreases the concentration of dissolved carbon dioxide (CO2) in water.

As water is agitated or mixed with air, carbon dioxide—a gas that is often more soluble in water—escapes into the atmosphere. This decrease in dissolved CO2 can be beneficial for various aquatic environments and drinking water systems, as high concentrations of carbon dioxide can lead to lower pH levels, potentially causing issues such as corrosion or harmful conditions for aquatic life.

In contrast, the other options do not reflect the general effects of aeration accurately. Aeration does not increase CO2; rather, it decreases it by promoting the escape of this gas. The influence of aeration on calcium is not a direct effect, as the aeration process primarily concerns gas exchange rather than the removal of mineral content like calcium. Lastly, aeration does not lead to a decrease in oxygen content; in fact, it is intended to increase the oxygen saturation in the water, improving conditions for aerobic biological processes.