Effect of fulvic acid on the sorption of Cu and Pb onto γ-Al2O3

Competitive adsorption of strontium and fulvic acid at the muscovite–solution interface observed with resonant anomalous X-ray reflectivity

“…Dissolved organic matter (DOM) also complexes with metal ions in solution, and changes the affinity of the metal species for mineral surfaces (Raspor et al, 1984;Ticknor et al, 1996;Schroth and Sposito, 1998;Christl and Kretzschmar, 2001). Metal uptake can be either enhanced (Bäckströ m et al, 2003) or decreased (Collins et al, 1999;Boily and Fein, 2000;Wu et al, 2003a;Arias et al, 2004) depending on the sorption strength of these metal-organic complexes compared to the inorganic cations.…”

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).…”

Simultaneous adsorption of copper ions and humic acid onto an activated carbon

“…Humic acids (HAs) contain many organic functional groups such as carboxylic, phenolic, hydroxyl, amine, and quinone groups, which provide a number of different potential binding sites for metal ions [2,3]. They play an important role in metal speciation in natural waters [1][2][3][4][5].…”

“…The surface properties of carbons may be changed when HAs are adsorbed. Adsorption of HAs onto carbons causes an increase in the surface negative charges as well as pore blockage [5][6][7][8].…”