Transformation of jarosite during simulated remediation of a sandy sulfuric soil.

摘要: Abstract Aeration of wetland soils containing iron (Fe) sulfides can cause strong acidification due to the generation large amounts sulfuric acid and formation Fe oxyhydroxy sulfate phases such as jarosite. Remediation by re-establishment anoxic conditions promotes jarosite transformation oxyhydroxides and/or sulfides, but driving mechanisms are largely unresolved. We investigated a sandy, jarosite-containing soil (initial pH = 3.0, Eh ~600 mV) in laboratory incubation experiment under submerged conditions, either with or without wheat straw addition. Additionally, model composed synthesized mixed quartz sand was used. values were monitored weekly. Solution concentrations total dissolved organic carbon, Fe, S, K well proportions Fe2+ SO42- analysed at end experiment. Sequential extraction, X-ray diffraction, Mossbauer spectroscopy used characterize mineral composition soils. Only when added natural artificial soils, increased up 6.5, decreased approx. 0 mV. The release (mainly Fe2+), K, S SO42-) into solution indicated redox- pH-induced dissolution Mineralogical analyses confirmed losses both While lepidocrocite formed soil, goethite soil. Both showed also increases non-sulfidized, probably organically associated Fe2+/Fe3+, no (re-)formation sulfides. Unlike not prone support re-acidification case future aeration. Thus, inducing moderately reductive controlled supply matter could be promising way for remediation sediments acidified oxidation materials.