Abstract: Device for processing effluents includes: a container for cultivating algae and/or microorganisms in an aqueous medium; supply elements for the algae and/or microorganism culture; elements for injecting an effluent into the algae and/or microorganisms, the effluent coming from a building; elements for adjusting the temperature of the algae and/or microorganism culture; effluent recovery elements for recovering the effluent from a building and for injecting the same into the algae and/or microorganism culture; and optionally a lighting system for promoting the growth of the algae and/or microorganism culture. The device can be used for producing biofuel, organic molecules, chemical compounds and proteins. The biofuel thus obtained may consist of oleaginous biomass, for example, which can directly be used in a thermal power plant or be converted by pyrolysis into coal or biopetroleum.