Iron-rich colloids as carriers of phosphorus in streams: A field-flow fractionation study

A synthesis of the impacts of ditch network maintenance on the quantity and quality of runoff from drained boreal peatland forests

“…These contradictory results are difficult to explain, particularly those of Å ström et al 2002, who analyzed total P (unfiltered samples), the export of which could be expected to increase along with that of SS and adhered particulate P. One factor affecting the variation between studies could be Joensuu et al (2006) the amount of iron (Fe)-phosphorus minerals in the ditch bottom soils, which can release P-rich Fe phases after DNM (Å ström et al 2002). In addition, the formation of Fe-humic colloids also affects the transport of SS and adhered P (Baken et al 2016). One more explaining factor for the variable results could be the amount of easily soluble P in the peat, which varies by the fertility of the site (Nieminen and Penttilä 2004).…”

Elemental Composition of Natural Nanoparticles and Fine Colloids in European Forest Stream Waters and Their Role as Phosphorus Carriers

“…It has already been shown that NNP can bind the majority of P present in soil solutions (Hens & Merckx, ) and stream waters (Gottselig et al, , ) and that they can even support plant uptake of P from solution (Montalvo wt al., ). First results indicate that organic matter, Fe, and/or Al may be major binding partners for P in NNP of an acidic forest river system and that the binding of P varies depending on the stream water composition (Baken, Regelink et al, ; Gottselig et al, ). Under the acidic conditions that characterize many natural settings (particularly many coniferous forest soils), surfaces of metal (hydr)oxides are positively charged and thus act as strong binding partners for negatively charged nutrients like P (Hasselloev & von der Kammer, ; Richardson, ) and organic matter (Celi & Barberis, ).…”

“…Organic matter associated with NNP and larger colloids also contains P (Darch et al, ). Some authors even assume that in the smaller size ranges, organophosphorus compounds can also act as the primary building blocks of NNP (Regelink et al, ), although these building blocks are more commonly thought to be aluminosilicates, organic matter (org C) or oxides and/or hydroxides of iron (Fe), aluminum (Al), and manganese (Mn) (Baken, Regelink et al, ; Hartland et al, ; Lyven et al, ; Regelink et al, ). At elevated pH levels in stream water, calcium (Ca) is increasingly present in the colloids and associated with P in the form of Ca phosphates.…”

Autumn Storms Trigger Enhanced Export of Iron, Phosphorus, and Carbon From a Forested Vermont Catchment

“…Previous studies have indicated that Fe may exert a strong control on the bioavailability and transport of P through colloidal Fe oxyhydroxides (Baken et al 2015b), Fe hydroxyphosphate colloids (van der Grift et al 2014), and Fe oxyhydroxide--humic substances (Baken et al 2016). Although no statistically significant relationships were evident between P and Fe under baseflow conditions, some patterns did arise during storms.…”