Effects of road traffic on photosynthetic pigments and heavy metal accumulation in tree species of Kumasi Metropolis, Ghana

Effects of biochar on the physiology and heavy metal enrichment of Vetiveria zizanioides in contaminated soil in mining areas

The effects of biochar addition on the physiological and biochemical characteristics of Vetiveria zizanioides, and the enrichment of heavy metals, were studied herein. The aim was to provide a theoretical reference for biochar to regulate the growth of V. zizanioides in the heavy metal-contaminated soil of mining areas and the enrichment capacity of Cu, Cd, and Pb. The results showed that the addition of biochar significantly increased the contents of various pigments in the middle and late growth stages of V. zizanioides, reduced the contents of malondialdehyde (MDA) and proline (Pro) in each growth period, weakened the peroxidase (POD) activity during the entire growth period; superoxide dismutase (SOD) activity decreased in the initial stages and substantially increased in the middle and late stages. The addition of biochar reduced the enrichment of Cu in the roots and leaves of V. zizanioides, while the enrichment of Cd and Pb increased. In conclusion, it was found that biochar could reduce the toxicity of heavy metals in contaminated soil in the mining area, affect the growth of V. zizanioides and its accumulation of Cd and Pb, and is, therefore, beneficial to the restoration of contaminated soil and the overall ecological restoration of the mining area.

The potential of using Cedrus atlantica as a biomonitor in the concentrations of Cr and Mn

Air pollution is becoming increasingly dangerous which is quite a significant issue of today's world, especially air pollution from heavy metal, whose emission increases with industrial and traffic activities. This is of great importance in terms of environmental pollution and human health. Heavy metals do not deteriorate and disappear easily on earth. They are liable to bioaccumulate within cells in organisms. Most of them demonstrate harmful effects in addition as a result of advanced accumulation, and thus they emerge as toxic and carcinogenic. Therefore, it is of great importance to observe the changes in heavy metal concentrations in the air. One of the most effective techniques for monitoring the change of heavy metal concentrations in the atmosphere is the use of annual rings of trees as biomonitors. In this study, in the annual rings of the Cedrus atlantica Manetti tree cut at the Kastamonu province at the end of 2019, the variation of the concentrations of some of the heavy metals most associated with traffic density was tried to be determined. Within the scope of the study, Cr and Mn concentration in the outer bark and the inner bark was compared with the direction and wood for the variation of heavy metal concentrations. Also, variance analysis and Duncan test were applied and evaluated. As a result of the study, while the highest values in many heavy metals are generally obtained in the outer bark, the transfer of metals in the wood is limited, and some heavy metal concentrations change significantly depending on the direction, especially in the wood. This change is related to the traffic density, so Cedrus atlantica Manetti annual rings are very suitable as biomonitors for air pollution control.