Thiosulphate-induced mercury accumulation by plants: metal uptake and transformation of mercury fractionation in soil - results from a field study
- 559 Downloads
The thiosulphate induced accumulation of mercury by the three plants Brassica juncea var.LDZY, Brassica juncea var.ASKYC and Brassica napus var. ZYYC and the transformation of mercury fractionation in the rhizosphere of each plant was investigated in the field.
Experimental farmland was divided into control and thiosulphate plots. Each plot was divided into three subplots with each planted with one of the plants. After harvesting, the mercury concentration in plants, mercury fractionation in rhizosphere soil before and after phytoextraction, and the vertical distribution of bioavailable mercury in bulk soil profiles was analyzed.
The cultivar B. juncea var.LDZY accumulated a higher amount of mercury in shoots than the other two plants. Thiosulphate treatment promoted an increase in the concentration of metal in plants and a transformation of Fe/Mn oxide-bound and organic-bound mercury (potential bioavailable fractions) into soluble and exchangeable and specifically-sorbed fractions in the rhizosphere. The observed increase in bioavailable rhizosphere mercury concentration was restricted to the root zone; mercury did not move down the soil profile as a function of thiosulphate application to soil.
Thiosulphate-induced phytoextraction has the potential to manage environmental risk of mercury in soil by decreasing the concentration of mercury associated with potential bioavailable fraction that can be accumulated by crop plants.
KeywordsPhytoextraction Mercury fractionation Definition of bioavailable mercury Environmental risk
This research was financed by the Natural Science Foundation of China (41030752, 41021062).
- CNEPA (Chinese National Environment Protect Agency) (1995) Environmental quality standard for soils, GB15618-1995, pp.1–6 (In Chinese)Google Scholar
- Haag-Kerwer A, Schäfer HJ, Heiss S, Walter C, Rausch T (1999) Cadmium exposure in Brassica juncea causes a decline in transpiration rate and leaf expansion without effect on photosynthesis. J Exp Bot 50:1827–1835Google Scholar
- Hamon RE, McLaughlin MJ (1999) Fifth International Conference on the Biogeochemistry of Trace Elements (ICOBTE), Vienna. pp. 908–909Google Scholar
- Lu R (2000) Chemical analysis method of agricultural soil. China Agricultural Science Press, Beijing (In Chinese)Google Scholar
- Rio M, Font R, Fernandez-Martinez J, Domínguez J, Haro A (2000) Field trials of Brassica carinata and Brassica juncea in polluted soils of the Guadiamar river area. Fresen Environ Bull 9:328–332Google Scholar
- Rodriguez L, López-Bellido F, Carnicer A, Alcalde-Morano V (2003) Phytoremediation of mercury-polluted soils using crop plants. Fresen Environ Bull 12:967–971Google Scholar
- Ullah MB (2008) Mercury Stabilization using Thiosulphate and Thioselenate. Dissertation, University of British ColumbiaGoogle Scholar
- Wang J, Feng X, Anderson CWN, Zhu W, Yin R, Wang H (2011b) Mercury distribution in the soil–plant–air system at the Wanshan mercury mining district in Guizhou, Southwest China. Environ Toxicol Chem 30:2725–2731Google Scholar
- Wang J, Feng X, Anderson CWN, Xing Y, Shang L (2012a) Remediation of mercury contaminated sites-a review. J Hazard Mater 221-222:1–18Google Scholar
- Wang J, Feng X, Anderson CWN, Wang H, Zheng L, Hu T (2012b) Implications of mercury speciation in thiosulphate treated plants. Environ Sci Technol 46:5361–5368Google Scholar