Effect of thioligands on plant-Hg accumulation and volatilisation from mercury-contaminated mine tailings

• Published in: Plant and soil Vol. 275; no. 1-2; pp. 233 - 246
• Main Authors: Moreno, F.N, Anderson, C.W.N, Stewart, R.B, Robinson, B.H, Nomura, R, Ghomshei, M, Meech, J.A
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.08.2005; Springer Nature B.V
• Subjects: Accumulation; Acid soils; Agronomy. Soil science and plant productions; ammonium thiocyanate; ammonium thiosulfate; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biotechnology; Brassica; Brassica juncea; Conservation, protection and management of environment and wildlife; Contamination; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Environment and pollution; Environmental degradation: ecosystems survey and restoration; Fundamental and applied biological sciences. Psychology; Gold; Gold mining; Groundwater pollution; heavy metals; hydrogen peroxide; Industrial applications and implications. Economical aspects; Leachates; ligands; Mercury; mine spoil; Mine tailings; Mine waste; Mine wastes; Miscellaneous; phytoremediation; Plant roots; Plants; pollutants; polluted soils; potassium permanganate; Sedimentary soils; Soil contamination; Soil erosion, conservation, land management and development; Soil pollution; Soil science; Soil water; Substrates; sulfuric acid; Tailings; thiols; uptake mechanisms; Vaporizing; Brazil; China; China, People's Rep; Sulfur compounds; Ligand; Nitrogen compounds; mine tailings; Soil pollution; Environmental engineering; Restorative plant; Chemical pollution; Mining; Decontamination; Cruciferae; Dicotyledones; Volatilization; Angiospermae; phytoextraction; Extraction; Bioremediation; Ammonium Thiosulfates; Brassica juncea; Gold ore; Ammonium Thiocyanates; Heavy metal; Phytoremediation; Chemical treatment; Ammonium compound; volatilisation; Spermatophyta; plant-Hg accumulation; Biological accumulation; Soil plant relation; Mercury; thioligands; Chemical contamination; Mining waste
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-005-1755-0

This study investigated the effect of thioligands on mercury (Hg) volatilisation and plant accumulation for Brassica juncea plants grown in mine tailings collected from artisanal gold mines in Brazil (the Serra Pelada mine) and China (the Gold Mountain mine). Plants were treated with either (NH₄)₂S₂O₃ or NH₄SCN and enclosed in gas-tight volatilisation chambers. Elemental Hg released from substrates was captured in a two-trap system containing 5% KMnO₄ dissolved in ₂NH₂SO₄. Mercury accumulation was enhanced in the presence of (NH₄) ₂S₂O₃ for plants grown in GM tailings. There was no significant increase in the plant-Hg accumulation after application of NH₄ SCN to the SP tailings. Volatilisation from planted substrates was not affected by the application of thioligands to either GM or SP mine tailings. Mercury volatilisation from planted substrates was significantly higher than from control substrates. Abiotic (photoreduction) and biotic (microbial interactions) factors might be linked to the enhanced plant effect on Hg volatilisation. There was no significant correlation for the Hg mass released from substrates and the amount of Hg uptake by roots and translocated to shoots. Our results indicate that volatilisation and plant-Hg accumulation are two independent processes. Thiosulphate-induced plant-Hg accumulation may be a potential tool for the phytoextraction of Hg contaminated soils but there are risks of groundwater contamination by Hg-containing leachates.