Distribution of heavy metals in contaminated river sediment

Sediment was collected from the Ell-Ren River for analysis, to assess the influence of geochemical components in the sediment on remobilization of heavy metals into pore water and on distribution of each heavy metal in five geochemical phases (exchangeable, carbonates, Mn-oxides, Fe-oxides, and organic matters (OM)) in the sediment. Average distribution coefficients, the ratio of heavy metal in pore water to total extractable heavy metal (TEHM), were found in the decreasing order of Co, Zn, Cd, Ni, Pb, Cr, and Cu. Each of the seven heavy metals in five geochemical phases correlated positively with OM but, except for Cd, did not correlate with Fe-oxides. Pb, Zn, Ni, and Cr in pore water correlated negatively with carbonates and Mn-oxides in the sediment, and again did not correlate with Fe-oxides. Significant correlations were also observed between Zn, Cd, Ni, Pb, and Cr in pore water and OM. Principal component analysis results illustrate that the geochemical behavior of different forms of Zn, Pb, Cr, Cu, Ni, and Cd (TEHM, heavy metal in five geochemical phases, and heavy metal in pore water) in association with OM is similar.