What is the function of reject water in a dialysis system?

The function of reject water in a dialysis system is primarily to dispose of solutes that have been removed during the dialysis process. In dialysis, water flows through a semi-permeable membrane that separates the dialysate from the blood. The purpose of this arrangement is to facilitate the exchange of waste products, excess ions, and other solutes from the blood into the dialysate while retaining important blood components.

When solutes are transferred from the blood to the dialysate, they become part of the reject water. This reject water effectively carries away impurities and waste products that need to be removed to maintain the patient's health. By disposing of this reject water, the dialysis system ensures that harmful substances are not returned to the blood, thus playing a critical role in the overall effectiveness and safety of dialysis treatments.

Other options don't align with the function of reject water; for instance, reject water does not purify the final product, serve as a backup water source, or increase water pressure in the dialysis system. Its main role is focused on the removal of solutes, making it essential in the process of maintaining the appropriate balance of electrolytes and waste products in the patient's body.