An assembly includes a housing with opposite first and second layers. The first and second layers are spaced apart to define a confined interior space. A semi-permeable membrane is attached to the first layer, the semi-permeable membrane covering a porous area portion of the first layer. An outlet port and an inlet port are in fluid communication with the interior space. The assembly includes a first circulator for circulating a first fluid between the outlet port and the inlet port, and a second circulator for circulating a second fluid along an exterior surface of the semi-permeable membrane. The second circulator includes a fluid duct attached to or integrated within the housing. The fluid duct is isolated from the interior space and is porous to provide fluid access to an exterior surface of the semi-permeable membrane. The semi-permeable membrane forms a barrier allowing exchange of compounds across the membrane.