The importance of microalgae biotechnology to the wastewater treatment and biofuels production/ A importância da biotecnologia das microalgas para o tratamento de águas residuais e a produção de biocombustíveis

Abstract

After the Second Industrial Revolution, the use of fossil fuels increased due to growth of cities. The burning of these fuels results in air pollution, which can cause health problems in the most sensitive population, environmental impacts due to SO2, and CO2 emissions in the atmosphere that add to the greenhouse effect. The unbridled consumption of fossil fuels, a non-renewable resource, has stimulated many countries to invest in different types of renewable energies including biofuels. Biofuels can be produced from agricultural crops (first generation); residual biomass from the agricultural sector, which are not fit to the human consumption (second generation); residual microalgae biomass (third generation); and genetically modified microalgae biomass (fourth generation). The microalgae have become an attractive resource for biofuel production because they do not require arable lands for their cultivation and can use wastewater as growth medium, while simultaneously treating this effluent by assimilating the pollutants presents in these waters (nitrogen, phosphorus, and metals). The aim of this work is to analyze the relevance of microalgae applied for wastewater treatment and biofuels production, through an exploratory literature review. Wastewater treatment using microalgae is well documented and presents efficient results for biofuels production; nevertheless the use of microalgae is still in the development phase and the major barrier being economic viability. Additional studies are recommended that explore more microalgae species and focus on genetic engineering to make this biotechnology economically viable