Pollution Characteristics and Potential Ecological Risk of Heavy Metals in the Sediments of Beijiang River in Qingyuan, China

The concentration of eight heavy metals (Pb, Cd, Cu, Zn, Ni, As, Hg and Cr) in sediment of Beijiang River was measured, the average concentration of Pb, Cd, Cu, Zn, Ni, As, Hg and Cr was up to 102.9, 3.668, 47.7, 248.9, 34.61, 17.385, 0.372 and 31.60 (mg·kg -1 ),which obviously higher than the corresponding natural background value except Cr. Geoaccumulation index (Igeo) was introduced by Mullerand the potential ecological risk index was introduced by Hakanson were employed to access the pollution of heavy metals, the Igeo value of eight heavy metals was in the order of Cd>Hg>Zn>Cu>Ni≈Pb>As>Cr, and the monomial potential ecological risk(E i ) value of eight heavy metals was in the decreasing order of Cd>Hg>Pb>Ni>As>Cu>Zn>Cr,which was different from the results of geoaccumulation index due to the introduction of metal toxic factor. From the analysis above, the contamination of Cd and Hg of Beijiang River was most serious. Pearson's correlation analysis showed that there existed obvious correlation among the metals including Pb, Cd, Cu, Zn, As and Cr, suggesting that the source of heavy metals in sediment was similar, and may caused by anthoropogenic activities. Accordingly, the obtained results provided the theoretical basis for managing the pollution of Beijiang River.