Title:
Is it Feasible to Produce Energy Crops in Heavy Metals Contaminated Soils?
Author(s):
Gomes, L., Costa, J., Barbosa, B., Santos, F., Fernando, A.L.
Document(s):
Paper
Abstract:
The production of energy crops has been presented as a promising alternative to partially replace fossil fuels and products of fossil origin. Among the various species which can be grown to generate energy, perennial crops are promising because of their high productivity and energy content. Oil crops, as sources for medium-chain fatty acids and medium-chain polymer building blocks, can be used for the production of plastics, surfactants, detergents, lubricants, plasticizers and other products, replacing fossil feedstocks. Yet, the increasing demand for biomass for the production of bioenergy, biomaterials and bioproducts is generating land-use conflicts which might be avoided through the establishment of marginal land for the production of dedicated energy crops, e.g. heavy-metal contaminated land. In this context, perennial and oil crop production under heavy metals contaminated soils was reviewed, with the aim to identify the concentration thresholds for the production of those crops with minor toxic effects. A preliminary evaluation of the data indicates that both perennial grasses and oil crops are potentially useful for phytoremediation of heavy metal contaminated soils. Most of the crops exhibited considerable tolerance to most of the metals and productivity was hardly affected by the potentially toxic concentrations of metals. Concentrations that affected most significantly the productivity of the plants are those that surpass 4 times the concentration limits accepted in soils (according to EU regulations) and when the bioavailable fraction to plants is high (exceeding 50% of the total). Most of the metals are preferentially accumulated in the belowground structures or in the leaves. Cadmium and zinc are the most mobilized elements, presenting higher translocation to the aboveground structures. Biomass obtained in contaminated soils presented higher ash content which can be a constraint for its processing and use. Nevertheless, these crops show potential to simultaneously deliver high yields, restore soil properties and promote groundwater protection by preventing heavy metals leaching. Their production in contaminated soils can also provide social and economic opportunities.
Keywords:
energy crops, heavy metals, land use, polluted soil, phytoremediation, contaminated soils
Topic:
Biomass Resources
Subtopic:
Biomass crops and energy grasses
Event:
27th European Biomass Conference and Exhibition
Session:
1BO.5.3
Pages:
80 - 83
ISBN:
978-88-89407-19-6
Paper DOI:
10.5071/27thEUBCE2019-1BO.5.3
Price:
FREE
