Phytodepuration of contaminated effluents obtained in hydrothermal carbonization processes

The scarcity of resources in recent decades has increased the search for new alternative and renewable forms of energy to fossil fuels. However, this transition must be carried out to achieve a more diversified energy system based on sustainability and environmental protection. In recent years, hydrothermal carbon-ization (HTC) has been considered an alternative process for processing value added products. This alter-native method is a thermochemical process that converts high moisture organic feedstock into carbon rich solids. However, during this process toxic organic and inorganic compounds present in the feedstock, such as hydrocarbons, are leached to a liquid phase that needs to be depurated. Phytodepuration is a technology based on the use of plants in the remediation of contaminated effluents, thus it’s a sustainable option that allows to simultaneously clean the contaminated waters obtained in the hydrothermal carbonization process and produce biomass that can be used in multiple applications. Camelina sativa is an energy crop that has the potential to produce biofuels, as well as, value added products from its oil. Several studies have shown that energy crops are tolerant to irrigation with contaminated waters. In this work we evaluated the phy-todepuration capacity of Camelina sativa (winter and spring varieties) when subjected to the irrigation of contaminated effluents obtained in hydrothermal carbonization process, as well as, the productivity and quality of biomass. The hydrothermal carbonization effluent (HTC) used in this study (360 mg / L O2) was diluted 1:3 (WW1: 120 mg / L O2), 1:2.4 (WW2: 150 mg / L O2) and 1:2 (WW3: 180 mg / L O2) to obtain the chemical oxygen demand (CDO) equal to 0.8, 1.0 and 1.2 times the limit value for wastewater dis-charges established by Decree Law 236/98. Also, the pots were irrigated with tap water as a control treat-ment. The results obtained led to the conclusion that the soil-biomass system was able to depurate the contaminated waters from the HTC process, ...