Speciation and size distribution of copper and zinc in urban road runoff.

The impact of pollutants from road runoff on receiving water bodies becomes increasingly serious. However, less is known about the study on the distribution of metal speciation in particles with different sizes, and the interaction among metal speciation. Our research is aimed at investigating speciation distribution of copper (Cu) and zinc (Zn) in particles and the interaction among metal speciation. Stainless steel sieves in different sizes were used to accomplish filtration scheme. Sequential extraction procedures contained five steps for the chemical fractionation of metals. Flame atomic absorption spectrometry (Shimadzu, AA-6800) was used to determine the concentration of metal speciation. Speciation distribution of Cu was similar to that of Zn. Size distribution implied that small particles (<75 μm) determined the distribution for both Cu and Zn, as well as their migration. Correlation analysis indicated that the interaction among speciation of Cu was different from that of Zn.