Pedosphere 33(5): 744--753, 2023
ISSN 1002-0160/CN 32-1315/P
©2023 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Influence of soil physicochemical properties, particle size fractions and mineralogy on the leaching potentials of arsenic and antimony in abandoned mine soils |
A. S. M. Fazle BARI1,2, Dane LAMB3, Geoff R. MACFARLANE4, Mohammad Mahmudur RAHMAN1 |
1 Global Centre for Environmental Remediation(GCER), College of Engineering, Science and Environment, The University of Newcastle, Callaghan, NSW 2308(Australia)
2 Department of Soil Science, Sher-e-Bangla Agricultural University, Dhaka 1207(Bangladesh)
3 Chemical and Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria 3000(Australia)
4 School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308(Australia) |
| ABSTRACT |
| At abandoned mine sites, arsenic (As)- and antimony (Sb)-enriched soils are often disposed of through onsite burial or capping. In highly weathered mine sites, the mobility of As and Sb is typically controlled by iron (Fe)(Ⅲ)/Fe(Ⅱ) phases; thus, the suitability of such disposal methods and appropriate testing techniques are questionable. In the present study, leaching potentials of As and Sb were examined using the toxicity characteristic leaching procedure (TCLP), waste extraction test (WET), and WET-extended procedure (WET-EXT) at three abandoned mine site soils in Australia. The leached concentration of As regularly exceeded USEPA criteria (5 mg L-1). The highest leached concentrations of As and Sb were observed in the finest particle size fraction (< 0.053 mm) by WET-EXT (1 040 mg L-1 for As and 21.10 mg L-1 for Sb) followed by WET (800 mg L-1 for As and 20.90 mg L-1 for Sb). The TCLP method resulted in the lowest concentrations of leached As (0.000 9 mg L-1) and Sb (0.000 3 mg L-1). Crystalline and amorphous As-bearing Fe oxides were the main phases in the soils studied. However, the best correlations of leached As determined by TCLP (0.832), WET (0.944), and WET-EXT (0.961) were found with the non-specifically sorbed (NS1) As fraction. The mineralogical and sequential extraction data clearly indicate the dominant role of Fe geochemistry in controlling leachability of As and Sb. The TCLP method was unlikely to be suitable for assessing leachability, as it exhibited no relationship with leachable Fe and substantially lower leached As and Sb than the other two methods. Given the high to extremely high leachable As and Sb concentrations, most of the soil samples would not be recommended for placement in capping works, old shafts, or reduction systems (e.g., collection in drainage basins). |
| Key Words: particle size fraction,sequential extraction,toxic element,toxicity characteristic leaching procedure,waste extraction test |
| Citation: Bari A S M F, Lamb D, Macfarlane G R, Rahman M M. 2023. Influence of soil physicochemical properties, particle size fractions and mineralogy on the leaching potentials of arsenic and antimony in abandoned mine soils. Pedosphere. 33(5): 744-753. |
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