Role of synthesized soil for minimizing heavy metal penetration into the plant’s cell in phytoremediation process

Abstract

The advantages of synthesized soil for minimizing the heavy metal penetration into the plant cells during phytoremediation process was investigated. The synthesized soil was prepared by modifying the as-received soil into fine and coarse particles via a sieving process before subjecting the prepared soil to the lotus plant for the phytoremediation process. The as-received soil was obtained from a common paddy soil and consist of major clay elements including SiO2, Fe3O4 and Ca. After the phytoremediation process for 30 days, the bulk water, soil and rhizomes were sent for inductively coupled plasma (ICP) optical emission spectrometry. The fine soil absorbed more metal content than the coarse soil and as-received soil. Further analysis was conducted by downsizing the as-received soil into the aqueous solution of pH 4, 6 and 8 and followed by an ultrasonication process. A nanometer order particle of 157, 78 and 100 nm with various particles's surface charge of 22, 4.9 and-19.9 mV were obtained from pH 4, 6 and 8 respectively. The surface charge of the clay element that contained in the as-received soil adsorbs the heavy metals onto its surface and hindered the penetration of heavy metal from entering the plant cells.