An apparatus for generating dialysate for dialysis comprising a dialysate outlet and a dialysate inlet and dialysate purifying means, wherein the purifying means comprise a cryopurifier for generating pure water, wherein the inlet of the cryopurifier is connected to the dialysate outlet and the outlet of the cryopurifier is connected to the dialysate inlet; and a method for reclaiming of fresh dialysate from ultrafiltrate and wasted dialysate extracted from a dialysis patient, comprising the following steps: preparing an ice slurry from the dialysate, wherein the ice slurry contains ice crystals and a liquid containing solutes; and separating the ice crystals from the liquid containing the solutes.