[Concentrations and distribution of heavy metals in urban sewage discharge channel of Tianjin].
Concentrations of metals, organic matter(OM), total nitrogen (TN) and total phosphorus (TP) were determined in sediment and soil samples collected from 15 selected sites along Dagu sewage discharge channel in Tianjin, China. Relative enrichment factors and correlation analysis were taken to study the distribution and pollution level of metals. The results show that pollution level is more serious in sediment than that in soil. Hg, Cd, Zn and Pb are more enriched while Cr, Ni and As are less enriched. Relative enrichment factors (REF) of Hg, Cd, Zn and Pb in sediment are 59.3, 25.4, 14.5 and 7.5, and that in soil are 8.44, 5.19, 6.6 and 3.3, respectively. The heavy metal concentrations greatly vary among different sampling sites, which is demonstrated by the fact that coefficient of variation (CV) varies from 74.4% to 110.8% in sediment. The highest enrichments of heavy metals are found in sampling site S4 and S12, which are affected by chemical industry wastewater. There is no significant correlation between metal concentrations in sediment and those in soil. The concentrations of heavy metals in sediment are not reciprocally correlated, either. However, significant correlations exist among many pollutants in soil. Hg, Cd, Zn and Pb are positively correlated with each other, at the same time they are positively correlated with OM, TN and TP, but Cr, Ni and As are poorly correlated with OM and TP, which suggests that Cd, Zn and Pb have similar environmental geochemical properties and are contaminated by anthropogenic impact. When compared with the main rivers in Tianjin, the enrichment of heavy metals in Dagu sewage discharge channel is relatively high.
Wu
Guang-hong
GH
Tianjin Key Laboratory of Water Environment and Water Resource, Tianjin Normal University, Tianjin 300387, China. wuguanghong@hotmail.com
Zhu
Zhao-zhou
ZZ
Liu
Er-bao
EB
Li
Wan-qing
WQ
Zheng
Hong-qi
HQ
D002681:China; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis*; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D019216:Metals, Heavy; D012722:Sewage; D014874:Water Pollutants, Chemical