70
Phytotechnology with Biomass Production
in the rooting environment, there are already some successful approaches,
particularly for the element Ni, applying naturally occurring hyperaccumulator plants on ultramafic soils. Bio-ores produced via phytomining have a
number of advantages compared to mineral ores, such as low energy demand
for melting and less emissions of sulfur dioxide. Furthermore, plants have the
capacity to synthesize nanoparticles with a high catalytic and absorptive activity. Nevertheless, optimizing processing of bio-ores for recovery of target elements and an improved understanding of plant–microbe–element interactions
and stimulation of rhizosphere processes (e.g., via co-cropping) to increase
bioavailability and thus accumulation of target elements in plants will be key
parameters for economic viability of phytomining at the individual business
company level. Economic return can be increased by utilizing bioenergy (fermentation, combustion) from accumulator plants; however, this requires more
breeding efforts considering the low biomass yield of most (hyper)accumulator
plants. Returning fermentation residues from biogas production as fertilizers
to field sites will not only increase biomass yield of accumulator plants via fertilizing effects but also close nutrient loops (circular economy). Furthermore,
application of organic matter from fermentation residues on marginal sites will
improve soil conditions, reduce soil erosion, and thus contribute to soil and
(ground-)water protection. In addition, sequestration of atmospheric CO 2 due
to long-term soil improvement allows sales of carbon dioxide credits, which
will not only increase financial returns on a microeconomic level but should
also be included as positive effects of phytomining at the macroeconomic level
as part of a more holistic economic and ecological evaluation of mining.
References
Ali, H., Khan, E., & Sajad, M. A. (2013). Phytoremediation of heavy metals—Concepts
and applications. Chemosphere, 91(7), 869–881. https://doi.org/10.1016/j.
chemosphere.2013.01.075.
Anderson, C. W. N., Brooks, R. R., Chiarucci, A., Lacoste, C. J., Leblanc, M., Robinson,
B. H., Simcock, R., & Stewart, R. B. (1999). Phytomining for nickel, thallium and
gold. Journal of Geochemical Exploration, 67(1–3), 407–415. https://doi.org/10.1016/
S0375-6742(99)00055-2.
Anderson, C. W., Brooks, R. R., Stewart, R. B., & Simcock, R. (1998). Harvesting a crop
of gold in plants. Nature, 395(6702), 553–554. https://doi.org/10.1038/26875.
Anderson, C., Moreno, F., & Meech, J. (2005). A field demonstration of gold phytoextraction technology. Minerals Engineering, 18(4), 385–392. https://doi.
org/10.1016/j.mineng.2004.07.002.
Anderson, C. W. N., Stewart, R. B. , Moreno, F. N., Wreesmann, C. T. J., GardeaTorresdey, J. L., Robinson, B. H., & Meech, J. A. (2003). Gold phytomining. Novel
developments in a plant-based mining system. Proceedings of the Gold 2003
Conference: New Industrial Applications of Gold.
Phytotechnology with Biomass Production
in the rooting environment, there are already some successful approaches,
particularly for the element Ni, applying naturally occurring hyperaccumulator plants on ultramafic soils. Bio-ores produced via phytomining have a
number of advantages compared to mineral ores, such as low energy demand
for melting and less emissions of sulfur dioxide. Furthermore, plants have the
capacity to synthesize nanoparticles with a high catalytic and absorptive activity. Nevertheless, optimizing processing of bio-ores for recovery of target elements and an improved understanding of plant–microbe–element interactions
and stimulation of rhizosphere processes (e.g., via co-cropping) to increase
bioavailability and thus accumulation of target elements in plants will be key
parameters for economic viability of phytomining at the individual business
company level. Economic return can be increased by utilizing bioenergy (fermentation, combustion) from accumulator plants; however, this requires more
breeding efforts considering the low biomass yield of most (hyper)accumulator
plants. Returning fermentation residues from biogas production as fertilizers
to field sites will not only increase biomass yield of accumulator plants via fertilizing effects but also close nutrient loops (circular economy). Furthermore,
application of organic matter from fermentation residues on marginal sites will
improve soil conditions, reduce soil erosion, and thus contribute to soil and
(ground-)water protection. In addition, sequestration of atmospheric CO 2 due
to long-term soil improvement allows sales of carbon dioxide credits, which
will not only increase financial returns on a microeconomic level but should
also be included as positive effects of phytomining at the macroeconomic level
as part of a more holistic economic and ecological evaluation of mining.
References
Ali, H., Khan, E., & Sajad, M. A. (2013). Phytoremediation of heavy metals—Concepts
and applications. Chemosphere, 91(7), 869–881. https://doi.org/10.1016/j.
chemosphere.2013.01.075.
Anderson, C. W. N., Brooks, R. R., Chiarucci, A., Lacoste, C. J., Leblanc, M., Robinson,
B. H., Simcock, R., & Stewart, R. B. (1999). Phytomining for nickel, thallium and
gold. Journal of Geochemical Exploration, 67(1–3), 407–415. https://doi.org/10.1016/
S0375-6742(99)00055-2.
Anderson, C. W., Brooks, R. R., Stewart, R. B., & Simcock, R. (1998). Harvesting a crop
of gold in plants. Nature, 395(6702), 553–554. https://doi.org/10.1038/26875.
Anderson, C., Moreno, F., & Meech, J. (2005). A field demonstration of gold phytoextraction technology. Minerals Engineering, 18(4), 385–392. https://doi.
org/10.1016/j.mineng.2004.07.002.
Anderson, C. W. N., Stewart, R. B. , Moreno, F. N., Wreesmann, C. T. J., GardeaTorresdey, J. L., Robinson, B. H., & Meech, J. A. (2003). Gold phytomining. Novel
developments in a plant-based mining system. Proceedings of the Gold 2003
Conference: New Industrial Applications of Gold.