Carbon tanks are primarily used to remove which of the following from water?

Carbon tanks are specifically designed to remove chlorine and chloramine from water. These substances are commonly found in municipal water supplies and are used as disinfectants. However, when water is used for hemodialysis, the presence of chlorine and chloramine can be harmful as they can cause hemolysis of red blood cells and other complications.

The process of carbon filtration works through adsorption, where chlorine and chloramine molecules adhere to the surface of the activated carbon, thereby reducing their concentration in the treated water. This is crucial because the dialysis process requires ultrapure water to ensure patient safety and optimal treatment outcomes.

In contrast, iron and manganese removal typically involves different types of filtration systems, such as oxidation and sedimentation, while nitrates are usually removed through processes like reverse osmosis or ion exchange. Hardness minerals, which contribute to water hardness, are often treated with water softening techniques rather than through carbon filtration. Hence, the effectiveness of carbon tanks in addressing the specific removal of chlorine and chloramine makes this the correct answer.