EDTA and organic acids assisted phytoextraction of Cd and Zn from a smelter contaminated soil by potherb mustard (Brassica juncea, Coss) and evaluation of its bioindicators.

Autor: Guo, Di1, Ali, Amjad1, Ren, Chunyan1, Du, Juan1, Li, Ronghua1, Lahori, Altaf Hussain1, Xiao, Ran1, Zhang, Ziyang1, Zhang, Zengqiang1 zqzhang@nwafu.edu.cn
Předmět:
Zdroj: Ecotoxicology & Environmental Safety. Jan2019, Vol. 167, p396-403. 8p.
Abstrakt: Abstract Phytoremediation of contaminated soil is an in-situ reclamation technique for removal of potentially toxic metals through hyperaccumulator plants. Potherb mustard (Brassica juncea, Coss.) is less explored for its assisted phytoextraction potential to restore and accelerate potentially toxic metals removal from smelter-contaminated soil. In this study, different levels of ethylene diamine tetraacetic acid (EDTA) alone and combined with citric acid (CA) and oxalic acid (OA) were applied in a greenhouse pot experiment. Chelates added on 25th d and 25/35th d after sowing, enhanced cadmium (Cd) and zinc (Zn) bioavailability in soil due to complexation. As a result, Cd and Zn in shoot and root were significantly amplified by 1.7, 2.15 and 1.93, 2.7 folds than control, respectively. Shoot and root dry weight significantly reduced and ranged between 4.13–9.91 and 0.21–0.77 g pot−1, respectively. The toxicity induced by potentially toxic metals in plant imposed a series of biological responses. Plant antioxidants like Phenylalanine ammomialyase (PAL), polyphenol oxidase (PPO) Catalase (CAT) content increased, except the peroxidase (POD) with the addition of chelating agents. Besides, biological concentration factor (BCF) of Cd and Zn, translocation factor (TF) of Cd were notably elevated (>1.0), while TF of Zn was reduced. Pearson correlation analysis showed a positive relation between DTPA-extractable and shoot concentration of Cd and Zn, whereas it showed negative correlation with plant dry weight. In general, chelate-assisted phytoremediation of smelter contaminated soil proved effective in this study, and followed the order: EDTA > EDTA + CA ≈ EDTA + OA > CK. Graphical abstract fx1 Highlights • Potherb mustard was efficient in extracting Cd and Zn from contaminated soil. • Potherb mustard produced enzymes to resist oxidative stress induced by Cd and Zn. • The efficiency of phytoextraction followed: EDTA alone > EDTA jointly > control. [ABSTRACT FROM AUTHOR]
Databáze: GreenFILE