Using Hydrophilic Tree Species for the Biological Removal of Cadmium in Contaminated Environments

In this study, the phytoremediation capacity of the hydrophilic tree species populus deltoides and Taxodium distichum and their ability to absorb cadmium (Cd) are investigated as a method for addressing the need for the removal of heavy metals from contaminated water and soil resources as a measure to counteract their environmental effects. For this purpose, a completely randomized design was used with 4 treatments (namely, 0, 50, 100, and 150 mg kg-1 of cadmium) and 3 replications. Results showed that Cd concentrations in the organs of the two species increased with increasing soil Cd content. The highest Cd concentrations in the leaves, stems, and roots (18.6, 35.33, and 89.06 in T. distichum and 29.44, 61.56, and 104.6 in p. deltoids, respectively) were observed for a Cd concentration of 150 mg Cd kg-1. The highest and lowest values of Cd concentration were observed in the roots and leaves, respectively, for all the Cd concentrations examined. Cd concentration exhibited a decreasing trend moving from roots to stems and leaves. The translocation factor increased in both species compared to the control and its greatest values (1.1065 and 1.006) were observed in the treatment with 50 mg Cd kg‒1 for p. deltoides and T. distichum, respectively. Given the importance of biological wastewater treatment and the removal of contaminants, especially heavy metals, from the environment aimed at optimal use of soil and water resources as goals of sustainable development, the cultivation of the hydrophilic species of p. deltoides and T. distichum may be recommended due to their high biomass production while the species also offer a high potential for phytoremediation and a great capacity for stabilizing soil cadmium.