Fractionation and size-distribution of metal and metalloid contaminants in a polluted groundwater rich in dissolved organic matter

I. Kozyatnyk , Sylvain Bouchet (1) , E. Björn , P. Haglund

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

We investigated the concentration levels, fractionation and molecular weight distribution (MWD) of dissolved organic matter (DOM) and metals (V, Cr, Co, Ni, Cu, Zn, As, Cd, Sn, Ba, Hg and Pb) in a polluted groundwater from an industrial area in Northern Sweden. DOM was mainly recovered in the hydrophobic acidic and hydrophobic neutral sub-fractions (45 and 35%, respectively) while most metals were found in the acidic sub-fractions (46–93%) except for V, Fe and As, which were predominant in the basic sub-fractions (74–93%) and Cd in the neutral ones (50%). DOM exhibited a broad MWD in groundwaters, usually from 5 to 200 kDa and was dominated by high molecular weight hydrophobic acids, low molecular weight hydrophilic acids and hydrophilic neutral compounds. Most of the studied metals (Fe, Cr, Co, Sn, Ba, Hg) were associated with the high molecular weight DOM fraction (ca. 40–100 kDa). Cu, Pb, Zn, Cd and Ni interacted with a broad range of DOM size fractions but were still most abundant in the high molecular weight fraction. Few metal/metalloids (As, V and Cr in some cases) presented a very weak affinity for DOM and presumably existed predominantly as “free” inorganic ions in solution. © 2016 Elsevier B.V.

Mots clés: Biogeochemistry; Biological materials; Cadmium; Concentration levels; copper; Dissolution; Dissolved organic matter; Dissolved organic matters; fractionation; Groundwater; Groundwater pollution; High molecular weight; Hydrophilicity; Hydrophilic neutrals; Hydrophobicity; Hydrophobic neutral; ICP-MS; Iron compounds; Lead; Low molecular weight; Metal binding; Metal recovery; Metals; Molecular weight; Molecular weight distribution; nickel; Organic compounds; Size exclusion chromatography; Tin; Well drilling; zinc

Domaines: Chimie

I. Kozyatnyk, Sylvain Bouchet, E. Björn, P. Haglund. Fractionation and size-distribution of metal and metalloid contaminants in a polluted groundwater rich in dissolved organic matter. Journal of Hazardous Materials, 2016, 318, pp.194--202. ⟨10.1016/j.jhazmat.2016.07.024⟩. ⟨hal-01495436⟩