In-vitro Assessment of Heavy Metal Removal from Contaminated Agricultural Soil by Native Plant Species

Abstract

Soil pollution by toxic metals such as cadmium (Cd), lead (Pb), chromium (Cr) and copper (Cu) is major problem in different agricultural areas of Pakistan especially Gujranwala and Lahore. The objective of this study was to assess the accumulation and uptake of toxic metals from contaminated soil by using local plants such as Soybean (Glycine max), Barley (Hordeum vulgare), Sunflower (Helianthus annuus), Pearl millet or Pearl millet (Pennisetum americanum), Maize (Zea mays), Canola (Brassica napus) and Wheat (Triticum aestivum). This study was based on the comparison of heavy metal concentrations and their accumulation in different parts of plants. In-vitro experiments were conducted by collecting soil from peri-urban areas of Gujranwala and Lahore being irrigated with untreated wastewater. Different seed varieties of local plants were brought from sale shop at National Agriculture Research Center (NARC) Islamabad. Seeds were germinated and grown in laboratory in ambient environment. Plants were irrigated with different levels of each toxic metal and a control was also run. Plant samples were harvested on 20th day and heavy metal concentrations were checked in roots and shoots of plants. Accumulation of heavy metals in the shoots and roots of local plants was measured using Flame Atomic Absorption Spectrophotometer (FAAS). The evidences provided by this experiment indicated that native crops like maize and canola were effective for phytoremediation of toxic metal polluted soil. In the future further experiments should be performed in order to investigate the phytoremediation potential of these crops for metals.