[Show abstract][Hide abstract] ABSTRACT: Heavy metals in municipal sewage sludge can limit the utilization of sludge resources, due to their recalcitrant characteristics and harmful effects. Here, ICP-MS was used to determine the total and special content of Pb, As and Cd in the sewage sludge from G and Q Wastewater Treatment Plants, Beijing. The air-dried samples were dissolved in HNO3-HClO4 before the total content determination, or, sequentially extracted with BCR three-step method before special content determination for the heavy metals. The total contents are 19.60, 37.96 and 1.34 mg x kg(-1) dry weight (DW) for Pb, As and Cd in the sewage sludge from G Plant; respectively; or, 19.58, 23.46 and 2.30 mg x kg(-1) DW in that from Q Plant, respectively. Pb and Cd decreased dramatically in the total contents, compared to the corresponding data in the late 20th century. Both G and Q sludge samples show similar patterns in the species distribution for the three heavy metals: most of Pb and As are HAc soluble, and least are H2O2 oxidative; while Cd mainly exists in NH2OH-HCl reductive state, seldom in HAc soluble state. Species with high ecotoxicity account for a major part (over 70%) of the three species for all the metals on the whole. The authors' results provide basic data for the ecological risk assessment and utilization of municipal sewage sludge from Beijing.
No preview · Article · Jul 2009 · Guang pu xue yu guang pu fen xi = Guang pu