Renewable biofuels (IMAGE) University of Montreal Caption Willows are naturally tolerant of contamination and their roots filter out nitrogen from wastewater, tripling the biomass produced, which can then be harvested to make renewable biofuels. Credit IRBV Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.