A system for concentrating a solution comprising: a first solution concentrating circuit comprising: a first humidification device (620a, 920a) comprising a first humidification media (624a, 924a); a first dehumidification device (660a, 960a) in gas flow communication with the first humidification device; a first solution flow path for flow of a first solution to be concentrated (605, 905) to the first humidification device; the first humidification media facilitating evaporation of liquid from the first solution to be concentrated to a first gas as the first solution to be concentrated passes through the first humidification media thereby concentrating the first solution and producing a first humidified gas (629a, 929a) for flowing from the first humidification device to the first dehumidification device; a second solution concentrating circuit comprising: a second solution container; a second humidification device (620b, 920b) comprising a second humidification media (624b, 924b); a second dehumidification device (660b, 960b) in gas flow communication with the second humidification device; a second solution flow path for flow of a second solution to be concentrated (662, 992) from the second solution container to the second humidification device; the second humidification media facilitating evaporation of liquid from the second solution to be concentrated to a second gas as the second solution to be concentrated passes through the second humidification media thereby concentrating the second solution and producing a second humidified gas (629b, 929b) for flowing from the second humidification device to the second dehumidification device, wherein the second dehumidification device is operable to condense vapour from the second humidified gas; and wherein the first dehumidification device comprises a first condensing heat exchanger (640, 940) in the second solution flow path such that the second solution to be concentrated passes internal the first condensing heat exchanger and is heated by heat generated from condensation of vapour from the first humidified gas on the external surface of the first condensing heat exchanger, the first condensing heat exchanger heating the second solution to be concentrated before the second solution to be concentrated enters the second humidification device; and one or more additional solution concentrating circuits positioned downstream of the second solution concentrating circuit such that a solution to be concentrated in an additional solution concentrating circuit is heated in a condensing heat exchanger of a dehumidification device of an upstream solution concentrating circuit before the solution to be concentrated enters a humidification device in the additional solution concentrating circuit. a first solution concentrating circuit comprising: a first humidification device (620a, 920a) comprising a first humidification media (624a, 924a); a first dehumidification device (660a, 960a) in gas flow communication with the first humidification device; a first solution flow path for flow of a first solution to be concentrated (605, 905) to the first humidification device; the first humidification media facilitating evaporation of liquid from the first solution to be concentrated to a first gas as the first solution to be concentrated passes through the first humidification media thereby concentrating the first solution and producing a first humidified gas (629a, 929a) for flowing from the first humidification device to the first dehumidification device; a second solution concentrating circuit comprising: a second solution container; a second humidification device (620b, 920b) comprising a second humidification media (624b, 924b); a second dehumidification device (660b, 960b) in gas flow communication with the second humidification device; a second solution flow path for flow of a second solution to be concentrated (662, 992) from the second solution container to the second humidification device; the second humidification media facilitating evaporation of liquid from the second solution to be concentrated to a second gas as the second solution to be concentrated passes through the second humidification media thereby concentrating the second solution and producing a second humidified gas (629b, 929b) for flowing from the second humidification device to the second dehumidification device, wherein the second dehumidification device is operable to condense vapour from the second humidified gas; and wherein the first dehumidification device comprises a first condensing heat exchanger (640, 940) in the second solution flow path such that the second solution to be concentrated passes internal the first condensing heat exchanger and is heated by heat generated from condensation of vapour from the first humidified gas on the external surface of the first condensing heat exchanger, the first condensing heat exchanger heating the second solution to be concentrated before the second solution to be concentrated enters the second humidification device; and one or more additional solution concentrating circuits positioned downstream of the second solution concentrating circuit such that a solution to be concentrated in an additional solution concentrating circuit is heated in a condensing heat exchanger of a dehumidification device of an upstream solution concentrating circuit before the solution to be concentrated enters a humidification device in the additional solution concentrating circuit.