Dialysate regenerator comprising reversible retainer

A dialysate regenerator, comprising:

• A purification means;
• At least one reversible retainer comprising an ion reservoir;
• A dialysate flow path comprising a dialysate inlet for receiving a dialysate, and a dialysate outlet for dispensing the dialysate;
• A plurality of valves for alternating a direction of the dialysate flow path through the at least one reversible retainer between a first direction and a second direction, the second direction being reverse to the first direction;
• and
• A pump connected to the dialysate flow path and configured to generate a flow of the dialysate from the dialysate inlet via the reversible retainer and the purification means to the dialysate outlet,
• Wherein the at least one reversible retainer is positioned upstream of the purification means in the first direction of the dialysate flow path and positioned downstream of the purification means in the second direction of the dialysate flow path, wherein the second direction of the dialysate flow path through the reversible retainer is reverse to the first direction of the dialysate flow path through the reversible retainer;
• or
• Wherein the dialysate regenerator comprises a first reversible retainer upstream of the purification means and a second reversible retainer downstream of the purification means.