Effects of a fulvic acid on the adsorption of mercury and cadmium on goethite

Geochemistry of Mercury Along a Soil Profile Compared to Other Elements and to the Parental Rock: Evidence of External Input

“…Several authors addressed the sorption behavior of aqueous Hg species on quartz and gibbsite (Sarkar et al 1999), kaolinite (Sarkar et al 2000), and goethite (Bäckström et al 2003;Kim et al 2004a, b), just to mention some of the phases present in the studied soil profile. The experimental results of those studies showed that Hg (II) species can be strongly sorbed by common clay minerals.…”

Freshwaters: which NOM matters?

“…In only three articles was a parameter other than OC used to characterise NOM. In two of them, fluorescence was measured (EEM in Katsuyama and Ohte (2002) and k ex /k em : 300/430 in Cruz et al (2005)) and, in a third one (Wang et al 2004), FTIR measurements were performed on fractions isolated using the Leenheer (1981) procedure on rainfall, throughfall, stemflow and stream water from Bäckström et al (2001) Inhibition of human plasmin by humic acids Isolated from drinking wellwater by absorption on XAD-7 column and Sephadex G-25 according to Aiken et al (1979) Hseu et al (2001) Cu partitioning onto suspended particulate matter Suwanneee River NOM concentrated by reverse osmosis Lu and Allen (2001) Chemical and microbial reduction of ferric ion…”

Distribution of barium and fulvic acid at the mica–solution interface using in-situ X-ray reflectivity

“…For example, adsorption of negatively-charged NOM on the surface of positively-charged oxide minerals causes a reversal of surface charge resulting in more electrostatically attractive surfaces for cations (Gessa et al, 1984;Schindler, 1990;Gu et al, 1996). Organic films may reduce a mineral's affinity for metal ions by blocking surface sorption sites or enhance it by providing additional sorption sites (Tipping, 1981;Dü ker et al, 1995;Bäckströ m et al, 2003;Wu et al, 2003;Strathmann and Myneni, 2005). Moreover, the interactions of dissolved organic matter (DOM) with metal ions determine the environmental distribution, speciation, and bioavailability of elements in aquatic ecosystems due to significant metal-ligand complexing (Raspor et al, 1984;Norden and Dabek-Zlotorzynska, 1996;Ticknor et al, 1996), which in turn affects how the metals sorb on mineral surfaces.…”

“…Commonly, cationic metal adsorption is enhanced at low pH, i.e., where HS sorption is maximized (Schroth and Sposito, 1998;Wang et al, 2000;Christl and Kretzschmar, 2001;Bäckströ m et al, 2003;Wu et al, 2003). However, the opposite effect occurs for anionic metal species such as (AsO 4 ) 3À or (SeO 3 ) 2À which compete with HS for sorption sites Grafe et al, 2001).…”