Photobioreactor devices and units for the production of biomass and remediation of environmental contamination are provided. The bioreactor devices comprise (i) a photobioreactor unit comprising a first membrane layer and a second membrane layer, the two membrane layers arranged such that at least a portion of the first membrane layer is directly bonded to at least a portion of the second membrane layer in order to form a defined boundary around non-bonded portions of the first and second membrane layers, thereby defining the photobioreactor unit capable of containing a fluid, wherein at least one of the first and second layers is translucent, and wherein at least a part of the first and second membrane layers is permeable to gases. The permeability coefficient of oxygen through the first and/or second membrane layer is suitably not less than about 100 Barrer, typically not less than about 300 Barrer, and suitably not less than about 500 Barrer. The photobioreactor unit also comprises an inlet and an outlet port to enable the fluid to circulate through said unit. Systems comprising the devices are provided as well as methods of using the devices for the production of biomass, remediation of wastewater and removal of atmospheric pollutants.