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Major Element, Trace Element, Nutrient, and Radionuclide Mobility in a Mining By‐Product–Amended Soil
Author(s) -
Douglas G.,
Adeney J.,
Johnston K.,
Wendling L.,
Coleman S.
Publication year - 2012
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2012.0139
Subject(s) - leachate , trace element , soil water , amendment , environmental chemistry , nutrient , soil conditioner , fertilizer , gypsum , chemistry , environmental science , mineralogy , geology , soil science , geochemistry , paleontology , organic chemistry , political science , law
This study investigates the use of a mineral processing by‐product, neutralized used acid (NUA), primarily composed of gypsum and Fe‐oxyhydroxide, as a soil amendment. A 1489‐d turf farm field trial assessed nutrient, trace element, and radionuclide mobility of a soil amended with ∼5% by mass to a depth of 15 cm of NUA. Average PO 4 –P fluxes collected as subsoil leachates were 0.7 and 26.6 kg ha −1 yr −1 for NUA‐amended and control sites, respectively, equating to a 97% reduction in PO 4 –P loss after 434 kg P ha −1 was applied. Total nitrogen fluxes in NUA‐amended soil leachates were similarly reduced by 82%. Incorporation of NUA conferred major changes in leachate geochemistry with a diverse suite of trace elements depleted within NUA‐amended leachates. Gypsum dissolution from NUA resulted in an increase from under‐ to oversaturation of the soil leachates for a range of Fe‐ and Ca‐minerals including calcite and ferrihydrite, many of which have a well‐documented ability to assimilate PO 4 –P and trace elements. Isotopic analysis indicated little Pb addition from NUA. Both Sr and Nd isotope results revealed that NUA and added fertilizer became an important source of Ca to leachate and turf biomass. The NUA‐amended soils retained a range of U‐Th series radionuclides, with little evidence of transfer to soil leachate or turf biomass. Calculated radioactivity dose rates indicate only a small increment due to NUA amendment. With increased nutrient, trace element, and solute retention, and increased productivity, a range of potential agronomic benefits may be conferred by NUA amendment of soils, in addition to the potential to limit offsite nutrient loss and eutrophication.