Researchers Testing Wastewater for Hydroponic Production

Scientists at the University of Illinois Urbana-Champaign tested the hydroponic germination of lettuce using aquaponic wastewater combined with liquid residual from hydrothermal liquefaction, an emerging technology that converts wet biomass to biocrude oil through a high-temperature, high-pressure process. This liquid residual is high in nutrients and would otherwise require wastewater treatment. In this study, solutions containing up to 8% of the liquid residual were viable for lettuce germination, and it remains to be seen how they would affect lettuce growth in later phases. Researchers suggest that the liquid residual could provide an alternative to chemical fertilizers derived from fossil fuels and contribute to the circularity of food production.