Title:
Improving the Sustainability of the Production of Crambe Oil when Cultivatedi in Soils Contaminated with Heavy Metals
Author(s):
Abias, M., Costa, J., Fernando, A.L.
Document(s):
Paper
Abstract:
Several crop species can be cultivated for the production of bioproducts, biomaterials, bioenergy and biofuels, representing an auspicious option for the partial substitution of fossil-based feedstocks. In addition, some crops can also tolerate and remove contaminants from the soil, potentiating soil remediation. Moreover, the production of energy crops in soils contaminated with heavy metals contributes to reducing land use competition with food crops and land use change controversies. Yet, the cultivation of industrial crops also demands fertilisers, pesticides and water, which contributes to reducing the sustainability of the value chains. One option is to apply in the irrigation, treated wastewaters, which also still have some nutrients, e.g. N, P, K and others. Oilseed crops represent a source of medium-chain fatty acids and medium-chain polymer building blocks that can be used for the production of plastics, surfactants, detergents, lubricants, plasticisers and other products. In this context, this work aims to assess the potential of crambe (Crambe abyssinica) for the production of oil for the bioeconomy along with the phytoremediation of heavy metal-contaminated soils. Therefore, Crambe abyssinica were sown in different soils artificially contaminated with Zn: 450 mg/kg; Pb: 450 mg/kg; Cd: 4 mg/kg; or Ni: 110 mg/kg, and irrigation was performed with treated wastewaters. This work was carried out in pots, under semi-controlled conditions, with the duration of one vegetative cycle. Control pots were also performed, using uncontaminated soil. Also, for the same contamination, not only irrigation with wastewaters was applied, but also, irrigation with tap water, in parallel pots, to compare and study the effect of the wastewaters on the growth, productivity and biomass quality of crambe grown in contaminated pots. Over the growing cycle, yields of Crambe abyssinica were on average 110 g/m2 and the crop presented a high tolerance index to the different heavy metal contaminated soils (> 0.75) and also to the wastewater used (>0.75). In fact, the irrigation of crambe with wastewater increased the yields in the pots (control pots, contaminated pots). Yet, the oil content in the seed was affected by the level of contamination in the soil and also by the application of wastewaters. A small increment was observed in protein content and ash content of the seeds, with a lower content in oil. The application of wastewaters significantly increases the protein content and ash content of the seeds, compared with the seeds’ composition in control and contaminated soils irrigated with tap water. In a biorefinery context, the cake can also be valorised, e.g. as adhesive resins or as anti-corrosion coatings.
Keywords:
heavy metals, land use, polluted soil, wastewater, oil crops, phytoremediation, contaminated soils
Topic:
Sustainable Resources for Decarbonising the Economy
Subtopic:
Sustainable integrated agricultural management practices
Event:
33rd European Biomass Conference and Exhibition
Session:
1DV.4.18
Pages:
209 - 213
ISBN:
978-88-89407-25-7
Paper DOI:
10.5071/33rdEUBCE2025-1DV.4.18
Price:
FREE
