A dialysis circuit (1； 11) of a usable artificial kidney comprising a dialysis filter (2), an inlet line (5) to feed a dialysis solution within said filter (2), an outlet line ( 6) to eliminate the dialysis solution of said filter (2) connected to said inlet line (5), an arterial line (3) that is responsible for transporting a patient's blood (P) to the filter (2), a venous line (4) that it is responsible for the transport of blood from the filter (2) to the patient (P), a plurality of pumps (3rd, 5th, 6th) adapted for the circulation of both the blood and the dialysis solution and a unit of purification (7) adapted to perform the filtration of the dialysis solution from said outlet line (6) and directed towards said inlet line (5)； said dialysis circuit is characterized in that said purification unit (7) comprises a filtration device (8) included in the group consisting of a nanofiltration filtration device or a microfiltration filtration device, and adsorption means (14； 34) arranged downstream of filtering device (14； 34) and adapted to retain molecules that you have not passed through said filtration device (13； 33).Un circuito de diálisis (1； 11) de un riñón artificial utilizable que comprende un filtro de diálisis (2), una línea deentrada (5) para alimentar a una solución de diálisis dentro de dicho filtro (2), una línea de salida (6) para eliminar lasolución de diálisis de dicho filtro (2) conectada a dicha línea de entrada (5), una línea arterial (3) que esresponsable del transporte de sangre de un paciente (P) al filtro (2), una línea venosa (4) que es responsable deltransporte de la sangre desde el filtro (2) hasta el paciente (P), una pluralidad de bombas (3a, 5a, 6a) adaptadaspara la circulación tanto de la sangre como de la solución de diálisis y una unidad de purificación (7) adaptada pararealizar la filtración de la solución de diálisis procedente de dicha línea de salida (6) y dirigida hacia dicha línea deentrada (5)； dicho circuito de diálisis se ca
