Phytostabilization of copper mine tailings with biosolids: Implications for metal uptake and productivity of Lolium perenne

• Published in: The Science of the total environment Vol. 395; no. 1; pp. 1 - 10
• Main Authors: Santibáñez, Claudia, Verdugo, Cesar, Ginocchio, Rosanna
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 20.05.2008; [Amsterdam; New York]: Elsevier Science; Elsevier Science
• Subjects: Applied sciences; bioaccumulation; Biodegradation, Environmental; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biosolids; Biotechnology; Chile; Copper - analysis; dry matter accumulation; Environment and pollution; Environmental Monitoring - methods; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; greenhouse experimentation; Heavy metals; Industrial applications and implications. Economical aspects; Lolium - growth & development; Lolium perenne; mine spoil; Mine tailings; Mining; Other industrial wastes. Sewage sludge; phytoremediation; polluted soils; Pollution; Semi-arid climate; semiarid zones; Soil - analysis; Soil - standards; Soil Pollutants - analysis; soil pollution; soil water; tissue distribution; uptake mechanisms; Wastes; Chile; South America; America; MED; Mine tailings; Semi-arid climate; Heavy metals; Biosolids; Monocotyledones; Waste treatment; Sewage sludge; Amendment; Absorption; Gramineae; Semi arid zone; Risk assessment; Angiospermae; Ecological recovery; Biological treatment; Lolium perenne; Translocation; Pollutant behavior; Copper ore; Tailings; Heavy metal; Phytoremediation; Industrial waste; Phytotoxicity; Environment impact; Solid waste; Spermatophyta; Performance; Mining waste; Phytostabilization
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2007.12.033

A greenhouse pot experiment was conducted to evaluate the feasibility of using biosolids and Lolium perenne for the phytostabilization of copper mine tailings and to evaluate the patterns of metal accumulation and translocation in plants. Biosolids were applied either on the surface or mixed with the tailings at rates of 0, 6, and 12% w/w. All pots were seeded with L. perenne and after six months, the plants were harvested and separated into roots and shoots for metal concentrations analyses as well as some physiological characteristics of the plants. In order to correlate the metal content in plant tissues with some chemical properties, the pore-water of the substrates was analyzed for metals, pH and dissolved organic carbon. Results showed that biosolids application increased the dry biomass production of L. perenne and the shoot concentrations of N and chlorophyll. On the other hand, biosolids increased the concentration of Cu and Zn in the pore-water and in plant tissues. Despite this, there were no evident symptoms of phytotoxicity and the concentration of metals was within the normal ranges described for plants and below the maximum tolerable level for animals. In addition, plant tissue analysis showed that the application of biosolids could significantly reduce Mo uptake and shoot accumulation in plants. The metals were taken up by plants in the following order: Cu > Zn > Mo > Cd. The distribution patterns of metals in plants showed that metals were mainly accumulated in the roots and only a small amount of them were transported to the shoots. These results suggest that mixed application of biosolids (6%) and the use of L. perenne could be appropriate for use in programs of phytostabilization of copper mine tailings. However, these results should be tested under field conditions in order to confirm their efficacy under semi-arid Mediterranean climate conditions.