1 research outputs found
Seasonal and spatial variations of heavy metalsin surface sediments collected from the BaoxiangRiver in the Dianchi Watershed, China
To explore potential ecological hazards due to heavy metals in the
Dianchi Lake Watershed, a three-stage European Community Bureau of
Reference (BCR) sequential extraction procedure was applied to examine
the spatial distributions and relative speciation ratios of Zn, Cu, Ni, Pb,
and Cr in Baoxiang River sediments during wet and dry seasons. The
metal species have similar spatial variations during different seasons. In
the upstream reaches of the Baoxiang River, heavy metals reside
primarily in the non-extractable residual fraction (72–90%). In the
midstream, the residual fraction (35–89%) remains dominant, but the
extractable fraction increases, featuring especially notable increases in
the reducible fraction (5–40%). Downstream, the Cu, Ni, Pb, and Cr
residual fractions remain high (46–80%) and the extractable fractions
increase rapidly; the Zn extractable fraction is quite high (65.5%).
Anthropogenic sources drive changes in heavy metal speciation.
Changes in the river environment, such as pH and oxidation-reduction
potential, also affect speciation. The reducible fraction of heavy metals
in Baoxiang River sediments is most sensitive to pH. Potential ecological
risk assessments for these five elements indicate that risks from Zn and
Pb are mild to moderate in the middle and lower reaches of the river.<br style="line-height: normal; text-align: -webkit-auto; text-size-adjust: auto;" /