The smallest proportions
of all four heavymetals (Cd, Pb, Cu, and Zn) for S5were associated with
the oxidizable fraction (1.1%–6.1%), which also made up the smallest
proportion of Cd for S6 (11.1%), whereas the smallest amount of Zn,
Cu, and Pb for S6was found in theHOAc extractable fraction, accounting
for 0.23%, 1.5%, and 0.46%, respectively.