This study aimed to present technologies in the processing of oily effluents through the physical-chemical flotation and biological wetland process generated in thermoelectric plants. This work is a literature review that uses keywords at the patent database of the Derwent World Patents Index (DWPI). Few studies were found for thermal power plant-effluent processing technologies and combined technologies for flotation and wetland effluent treatment. Patents indicated high efficiency in the combination of the processes. No studies were found in Brazil for treatment technologies of effluents in thermoelectric plants. However, due to the country's energy scenario, investments in research in this area are recommended.