Multivariate correlations of geochemical binding phases of heavy metals incontaminated river sediment

Distributions of geochemical binding phases of seven heavy metals (Cr, Cu, Co, Zn, Ni, Pb, and Cd) in sediment cores taken from six heavily polluted s ites of the Ell-Ren River in Southern Taiwan were studied. Sequential extra ction procedures (SEP) were used to determine the variations of heavy metal binding phases (exchangeable, bound to carbonates, bound to manganese-oxid es, bound to iron-oxides, and bound to organic matter) in different sedimen t depths. Multivariate analyses were used to explore the correlations among these geochemical binding phases of heavy metals. Results showed that the total amounts of various binding phases of heavy me tals significantly varied with sediment depth, but their binding behaviors in various phases did not significantly change with depth. The organic matt er content in the sediments increased with increasing Fe-oxide content. In addition, the binding affinities of carbonates with Zn, Pb, and Ni were hig her than the affinities of carbonates with the other heavy metals. The bind ing affinity of Fe-oxides with Cr was higher than the affinities of Fe-oxid es with the other heavy metals. Both correlation matrixes and principal com ponent analyses demonstrated that distributions of Cu, Zn, Ni, and Cd had s ignificant correlations with each other in both different depth horizons an d various geochemical binding