Heavy Metals Accumulation by Aromatic Plant Salvia Officinalis Irrigated with Treated Wastewater

Abstract

The use of wastewater for the irrigation of plants will contribute to the beneficial factors of plant growth, but it can damage human health because of the high concentration of toxic elements. The main goal of this research is to assess the concentration of some toxic heavy metals in the Salvia Officinalis plants after their harvest, which are irrigated with treated wastewater. Salvia Officinalis plants leaves are used in culinary and medicine. Sage plants are cultivated in an experiment using pots, in the greenhouse for 180 days. Treatments aim to assess the amount of elements (Cd, Cr, Cu, Pb, Ni and Zn), that are accumulated in plants irrigated with treated and untreated sewage waters. The concentration of these heavy metals in both treated and untreated sewage waters, are below the maximum permissible level in irrigation waters set by the World Health Organization (WHO). The development of plants and the content of heavy metal in their tissues are estimated. The results show that heavy metals content varied from spot to spot, plant to plant, and also in different parts of each plant. This study confirms that domestic sewage can effectively increase water resources for irrigation but the need for continuous monitoring of the concentration of toxic elements in soil, plants and water, still exists. It is required that plants should be checked for contaminant before processing them for pharmaceutical purposes or for human consumption.