Sustainable Energy from agro-industrial wastewaters in Latin-America

Conventional biological processes used to treat high-polluted agro-industrial effluents produce biogas and sludge, two by-products stocking up important energy contents. Advanced biotechnologies to treat these effluents are being developed to obtain increased biogas production and other efficient and useful energy sources, such as bio-hydrogen and even bio-electricity. Utilization of these clean energies is significantly lower than other renewables, particularly in developing regions such as Latin-America. This occurs despite the close link between the environmental benefits and sustainable use of this energy, which might be incorporated in different sustainable strategies for local and regional development. This study reviews the 'state of the art' of Latin-American research regarding technologies for energy recovery from agro-industrial wastewaters and their sustainable implementation. It also discusses the need for a more sustainable management of the water-energy nexus in treatment systems used to decont minate effluents, which should be committed to the improvement of renewable energy production and to a more extended regional use. Contributions of methodologies based on life cycle assessment (LCA) and criteria-indicators used to drive sustainability studies in this field are updated and used to outline a conceptual framework advising sustainable practices in this sector.