A sorbent polymer is provided that interacts or reacts with aqueous urea to aid the regeneration of a dialysate liquid. The sorbent polymer may include one or more specific functional groups bonded thereto. Such specific functional groups are selected from carboxylic acids, carboxylic acid esters, carboxylates, amides, dicarboxylic acids, dicarboxylic acid esters, and dicer boxylates to produce the desired urea sorbent.
