I
In chemistry, separation of suspended colloidal (see colloid ) particles from dissolved molecules via their unequal rates of diffusion through pores of semipermeable membranes (e.g., parchment, collodion, cellophane).
A slow process, dialysis may be accelerated by heating or by applying an electric field if the particles are charged.
II
or hemodialysis
Process of removing blood from a patient with kidney failure , purifying it with a hemodialyzer (artificial kidney), and returning it to the bloodstream.
Many substances (including urea and inorganic {{link=salt">salts ) in the blood pass through a porous membrane in the machine into a sterile solution; particles such as blood cells and proteins are too large to pass. This process controls the acid-base balance of the blood and its content of water and dissolved materials.