Abstract: Apparatus and method for make up of a hemodialysis solution and supply of same to an artificial kidney; the solution optionally contains bicarbonate in any desired amount. The apparatus comprises a recirculation loop which mixes a hemodialysis dialysate concentrate with deaerated water and may include another interconnected recirculation loop adopted to form an aqueous bicarbonate solution. Both recirculation loops mix the concentrates in the recirculation fluid in venturi means operated by continuously controlling the velocity of fluid flowing therethrough to create suction to inject the requisite quantity of concentrate to form the final desired composition in the product hemodialysis solution.