What process causes waste materials to pass out of the blood into the dialysis fluid?

The process that causes waste materials to pass out of the blood into the dialysis fluid is called diffusion. In dialysis, blood is exposed to a dialysis solution (dialysate) across a semipermeable membrane. Waste products and excess electrolytes in the blood move from an area of higher concentration (the blood) to an area of lower concentration (the dialysate) through this membrane, effectively cleansing the blood of unwanted substances. This process mimics the natural filtration function of healthy kidneys.