A photobioreactor (100) for use in treating polluted air and producing biomass may comprise, at least in part, a generally vertical tube or fluidic pathway (102), a generally vertical helical tube or fluidic pathway (104) having a light source (106) partially positioned within the helical fluidic pathway (104), a head cap assembly (108), and a base assembly (110). In one illustrative example, the light source (106) may be a light emitting diode (LED) or a plurality of light emitting diodes (LEDs). By one approach, a gas diffusion apparatus (112) is located at the base assembly (110) adjacent the generally vertical fluidic pathway (102).