[Distribution of heavy metals in PM10 and its release in the simulated acid rain]

The distribution of heavy metals in inhalable particulate matter (PM10), which were collected in Foshan during December of 2004, was characterized by scanning electron microscope-X-ray energy dispersive analysis technique (SEM-EDS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The releases of Cu, Pb, Zn and Cd were also examined for their potential releases in simulated acid rain, which were quantified with batch reactors. The results showed that the daily average concentration of PM10 was 0.19 mg/m(3), about 79% higher than the secondary standard of China. The relatively contents of Zn and Pb in PM10 were much higher than Cd and Zn, whereas the releasing rates of Cd and Zn in simulated acid rain were greater than that of Cu and Pb. The releasing rates of heavy metals from PM10 were increased as the pH of the acid rain decreased.