Munksgaard,N.C., Lottermoser,B.G. and Blake,K.(2012): Prolonged testing of metal mobility in mining-impacted soils amended with phosphate fertilisers. Water Air Soil Pollut., 223, 2237-2255.

『燐酸肥料で改良された鉱業からの影響の強い土壌における金属の移動性の長期試験』


Abstract
 The aim of the study was to determine whether the application of superphosphate fertiliser to soils contaminated with mine wastes can inhibit metal and metalloid mobility (Cu, Pb, Zn, Cd, Fe, Mn, As, Sb) in the long term. Contaminated soils contained sulfide- and sulfate-rich waste materials from the Broken Hill and Mt Isa mining centres. Results of long-term (10 months) column experiments demonstrate that fertiliser amendment had highly variable effects on the degree of metal and metalloid mobolisation and capture. Rapid release of metals from a sulfate-rich soil showed that phosphate amendment was ineffective in stabilising highly soluble metal-bearing phases. In a sulfide-rich soil with abundant organic matter, complexing of metals with soluble organic acids led to pronounced metal (mainly Cd, Cu and Zn) release from fertiliser-amended soils. The abundance of pyrite, as well as the addition of fertiliser, caused persistent acid production over time, which prevented the formation of insoluble metal phosphate phases and instead fostered an increased mobility of both metals and metalloids (As, Cd, Cu, Sb, Zn). By contrast, fertiliser application to a sulfide-rich soil with low organic carbon content and a sufficient acid buffering capacity to maintain near-neutral pH resulted in the immobilisation of Pb in the form of newly precipitated Pb phosphate phases. Thus, phosphate stabilisation was ineffective in suppressing metal and metalloid mobility from soils that were rich in organic matter, contained abundant pyrite and had a low acid buffering capacity. Phosphate stabilisation appears to be more effective for the in situ treatment of sulfide-rich soils that are distinctly enriched in Pb and contain insignificant concentrations of organic matter and other metals and metalloids.

Keywords: Mine waste; Metals; Fertiliser; Immobilisation; Remediation』

1. Introduction
2. Materials and methods
 2.1. Materials
 2.2. Material characterisation
 2.3. Laboratory experiments and analyses
 2.4. Quality control of geochemical data
3. Results
 3.1. Soils
 3.2. Feltiliser

 3.4. Chemical composition of leached soil columns
 3.5. Microprobe element mapping of amended soils
4. Discussion
 4.1. Phase reactions in amended and non-amended soils
 4.2. Element mobility in amended and non-amended soils
 4.3. Limitations of phosphate amendment
5. Conclusions
Acknowledgements
References


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