Competitive adsorption of phosphate on goethite in marine electrolytes

Groundwater-induced redox-gradients control soil properties and phosphorus availability across four headwater wetlands, New York, USA

“…It is widely known that SO 4 2-reduction enhances iron mineral dissolution and consequently releases P (Caraco et al 1989;Roden and Edmonds 1997;Smolders and Roelofs 1993), but other processes secondary to iron and sulfur redox reactions also can increase P mobilization (Gachter and Muller 2003). In particular, alkalinity generation enhances internal eutrophication by neutralizing acidity generated by microbial respiration (Lamers et al 1998a;Smolders et al 2003) and facilitating microbial mineralization (Lamers et al 2001;Lucassen et al 2004a;Roelofs 1991;Smolders et al 1995), as well as by inhibiting P sorption onto iron oxides in sediments (Hawke et al 1989). Reduced conditions also can increase available P due to microbial release of polyphosphates (Khoshmanesh et al 1999).…”

“…In addition, redox generated alkalinity could promote species diversity by buffering pH changes (Lamers et al 1998b;Smolders et al 2003) or by inhibiting P-sorption onto iron oxides (Hawke et al 1989;Moore and Reddy 1994). In fact, we have observed that species richness increased with alkalinity in NY fens (B.L.…”

“…Further, alkalinity generated as a by-product of reduction-oxidation reactions can increase P availability by stimulating mineralization and increasing internal nutrient release rates (Brouwer et al 1999;Curtis 1989;Lamers et al 2001;Lucassen et al 2004a;Roelofs 1991). This effect has been attributed to pH buffering (Lamers et al 1998a;Smolders et al 2003) and inhibition of P sorption onto iron oxides in sediments (Hawke et al 1989;Moore and Reddy 1994). These processes co-occur and therefore have a strong potential to significantly influence the inorganic P pool.…”

Evaluation of a Flue Gas Desulphurisation (FGD)-Gypsum from a Wet Limestone FGD as Adsorbent for Removal of Selenium in Water Streams

“…Nevertheless, these processes are not currently carried out in coalfired power plants owing to the expensive cost of maintenance and the discharges of large amount of sludge [14]. The adsorption of SeO 4 2-and SeO 3 2-has also been extensively studied [15][16][17][18][19][20]. However, all these studies have been focused on adsorption processes by conventional adsorbents such as hydrous ferric oxide, goethite, gibbsite, activated carbon, etc.…”

Sensitivity of surface complexation modeling to the surface site density parameter

“…Good quantitative descriptions of calcium, magnesium, cadmium, copper, and lead adsorption isotherm experimental data can be obtained with either inner-sphere (8-10) or outersphere (2, 1 1 ) surface complexes. For describing phosphate, selenite, arsenate, salycilate, and phthalate adsorption, use of either innersphere (12)(13)(14)(15)(16) or outer-sphere ( 17-19) complexes provides good fits to the experimental data.…”