Insights into Heavy Metals Leakage in Chelator-Induced Phytoextraction of Pb- and Tl-Contaminated Soil

• Published in: International journal of environmental research and public health Vol. 16; no. 8; p. 1328
• Main Authors: Huang, Xuexia, Luo, Dinggui, Chen, Xiangxin, Wei, Lezhang, Liu, Yu, Wu, Qihang, Xiao, Tangfu, Mai, Xiaotao, Liu, Guowei, Liu, Lirong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.04.2019; MDPI
• Subjects: Acid rain; Bioavailability; Biomass; Cadmium; Chelating agents; Chelation; Citric acid; Diamines; Efficiency; Environmental protection; Ethylenediaminetetraacetic acids; Experiments; Heavy metals; Leaching; Metals; Mineral resources; Organic acids; Oxalic acid; Plant extracts; Quality control; Reagents; Reference materials; Sediment pollution; Seeds; Soil contamination; Soil pollution; Soils; Zinc; China; DTPA; phytoextraction; leaching; maize; oxalic acid; lead; thallium
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph16081328

Chelators including DTPA (diethylene triamine pentaacetic acid) and oxalic acid were selected for inducing phytoextraction of heavy metals (HMs) from Pb-, Tl-, and Pb-Tl- contaminated soil, in which heavy metals leakage was highly remarkable. Results showed that compared with the control group without chelating agent under planting conditions, the extraction efficiency (i.e., uptake coefficient) of Pb, Tl increased by 86%, 43% from Pb-Tl- contaminated soil in the presence of oxalic acid, and there was no significant change in heavy metal leakage under rainfall conditions. It was the best phytoremediation scheme in this work. Under rainfall conditions, the HMs concentration in the leachate showed a linear decreasing trend. Acid rain promoted the leakage of heavy metals, and the average leached amount of Tl increased by 1.47 times under acid rain conditions. However, for Pb, DTPA was the main influencing factor, followed by acid rain.