Abstract:
Pollution has been on the rise ever since the industrial revolution. In Lebanon, water
and air pollution are among the most serious issues that require immediate solutions.
Further, soil pollution cannot be excluded since it affects water sources and human
nutrition. Soil pollution can happen due to hydrocarbon contamination or inorganic
contamination like metal presence. More specifically, there are heavy metals (HMs) that
if present above certain concentrations become contaminants to soils and crops.
In this work, the use of plants, specifically a hyperaccumulator seedling called poplar,
was explored as a remediation technique for cadmium (Cd) and nickel (Ni)
contamination in soil. A pot experiment was set up in a greenhouse compartment at the
American University of Beirut using synthetically contaminated clay soil to evaluate the
efficiency of poplar seedlings in phytoremediation during a period of six months and
was repeated with a second set of experiments. Further, the use of hyperspectral
imaging (HSI) to detect and quantify heavy metals absorbed by different parts of the
poplar plants was also assessed.
The results showed that cadmium mostly accumulates in poplar leaves while nickel is
found mostly in the roots of the plant. Roots of Ni-contaminated trees provided the most
consistent trend in hyperspectral imaging when compared to atomic absorption
spectrophotometry Ni concentrations results. Based on the above results and literature
findings for poplar pot experiments, poplar trees were not found to be very effective for
phytoremediation under the given experimental conditions of this work. Future work
should consider running the experiment for a longer time and with higher
concentrations to be assessed by the hyperspectral camera.
