Investigating the Efficiency of (Alhagi graecorum) Plant in Accumulating some Heavy Metals

Abstract

This study aimed to investigate the efficiency of the alhagi plant in adsorbing and accumulating heavy metals in the plant that grows naturally on both sides of the highway extending between the cities of Diwaniyah and Baghdad, passing through the city of Hilla. Plants grow 50 meters away on the sides of the main highway. The results showed that the lead concentration in the shoot and root system was higher than the permissible limit. The highest lead concentration was in Baghdad’s soil, and the lowest was in Diwaniyah. It is attributed to the momentum and traffic density of the city of Baghdad. The cadmium concentration in the shoots was less than the permissible limit, while it was higher in the root shoots, and the highest concentration appeared in the soil of Baghdad city. The cadmium concentration was less concentrated than the rest of the studied elements, lead, zinc, and nickel. The results showed that nickel was less than the permissible limit in the vegetative and root system. The zinc concentration in shoots was higher than the permissible limit, except in the soils of Hilla and Diwaniya at the right and left sides, respectively, it was less than the permissible limit. As for its concentration in the root system, it was higher than the permissible limit, except for the soil of Al-Diwaniyah city on the right side. The concentrations of the studied elements in the root system were higher than in the shoot system. The results of the plant pollution standards showed that the values of the bio concentration factor and the bioaccumulation factor for all studied elements are less than the value of one, which means that the alhagi plant is not considered one of the plants that accumulate heavy elements. Therefore, it is of limited benefit for the vegetative reclamation of soils contaminated with the studied heavy elements, except for the zinc element, as its values were between 0.1-10, which indicates that the sedum plant is a moderate accumulation of the zinc element. The results also present that the values of the local transmission coefficient for all the studied elements are more significant than the value of one. It indicates the movement and transfer of all elements from the root to the vegetative system.