Sedimentary iron geochemistry in acidic waterways associated with coastal lowland acid sulfate soils

Soil Amendments to Reduce Bioavailability of Metals in Soils: Experimental Studies and Spectroscopic Verification

“…The goethite has rough, spherical particle morphology (Figure 58b), which is similar to the morphology of akaganeite. Such goethite pseudomorphs have been observed previously in acidic sulfate soils (Sullivan and Bush, 2004;Burton et al, 2006) and strongly support the hypothesis that goethite is the transformed product from precursor akaganeite.…”

“…Under extremely reducing conditions, siderite can control Fe solubility in soil solution (Brennan and Lindsay, 1996). Microbial degradation of organic matter and anaerobic respiration of plant roots facilitates the accumulation of high concentrations of carbonate in the subsurface layer (Burton et al, 2006). Microorganisms are capable of anaerobic growth using sulfate as electron acceptor under reducing conditions (Kirk et al, 2004), and this dissimilatory reduction process will reduce sulfate to sulfide and release carbonate to the soil solution, which provides carbonate for the formation of siderite.…”

Reductive Dissolution and Reactivity of Ferric (Hydr)oxides: New Insights and Implications for Environmental Redox Processes

“…The interaction between ferric hydroxides is of paramount importance particularly in marine environments with ample pools of sulfide (e.g., [55]). Only recently, its importance has been highlighted also for terrestrial systems [60,61].…”

Effect of weathering on abundance and release of potentially toxic elements in soils developed on Lower Cambrian black shales, P. R. China

“…The acid sulfate soils are, in contrast to the black shale soils, developed in soft sediments deposited in brackish or saline waters (mostly during Holocene) and containing disseminated sulfides produced by seawater sulfate reduction (Boman et al 2008). The two soil types thus have different direct origins and sulfur sources, but like the black shale soils, the acid sulfate soils have a chemistry dominated by sulfide oxidation, metal release, and acidification (Å ström 1998; Burton et al 2006a) and thus behave, in an environmental context, in a manner similar to the black shale soils (Macdonald et al 2007;Burton et al 2006b;Fältmarsch et al 2008Fältmarsch et al , 2009Boman et al 2010). Because both soil types are characterized by high contents of easily mobilized metals, the soil layers and downstream waters are all characterized by acidification and metal loadings (Å ström and Björklund 1995;Nordmyr et al 2008;Å ström et al 2010).…”