| Tianjin Haihe River Basin was located downstream of the high-speed economic and social development of the Haihe River Basin brought a large number of industrial wastewater and domestic sewage, causing the region's water pollution is very serious. Duliujian River upstream industrial emissions of pollutants in petrochemical, metallurgical and other industries topped its waste water usually contains toxic and hazardous pollutants. Wherein the petrochemical industry emissions of pollutants generally contain biodegradable organic compound, the larger difficulty of traditional water treatment system, water quality compliance difficulties. In the upper reaches of poor water quality, river basin Duliujian serious pollutants and sources more complex, influenced by both conventional pollutants, but also the threat of high-risk pollution, water pollution overall situation is more serious. Stream sediment organic matter as "sink", the distribution of organic matter in the region rarely reported. In our research, we selected Duliujian river as our study object to analyze polycyclic aromatic hydrocarbons(PAHs, 16 species) and the heavy metal(Cd?Cr?V?Cu?Ni?Pb?Zn?Sn?As?Mo). Analysis of pollution characteristics Duliujian river Basin sediments persistent toxic pollutants, distribution, source analysis, evaluation of ecological risk The following conclusions have been made:(1) The total concentration of 16 PAHs in surface sediment of Duliujian river ranged from296 to 1094 ng·g-1, with an average concentration of 561ng·g-1, indicting a light pollution level. Of the 16 PAHs, middle and low ring PAHs dominated, Furthermore, high ring PAHs only 10%.. The PAHs in surface sediment of Duliujian river were maily derived from wood and coal burning, gasoline and diesel combustion and coke incineration. Although PAHs in surface sediment of Duliujian river were at low ecological risk, the average TEQBa P of PAHs were suggesting a certain of potential toxicity.(2) It indicated that all heavy metals but except V and Cr exceed 1.0 to 7.1 times respectively comparing to that of the background values. Enrichment factors for V, Cr and Ni in the surfaces sediments were less than 1.5, indicating that these 3 trace elements were originated from natural sources by using the principal components analysis(PCA). As for Cu, Zn, Cd, Pb, As, Mo and Sn, their enrichment factors in surface sediments were 5.36, 1.49, 7.29, 1.54, 7.67, 8.03 ? 2.91, respectively. PCA revealed that Cr, Zn and Cu were mainly influenced by anthropogenic activities, especially from the discharge of industrial wastewater. Comparing to the background values, the studied heavy metals in the surface sediments from the tributaries in the main urban districts had a moderate ecological risk. Potential ecological risk indexes(RI) was 313, with a range of 115 to 445 for the surface sediments from 16 selected tributaries. With applying Kriging interpolation in Arc GIS, RI values of heavy metals in the surface sediments presents obvious spatial differences.Duliujian drainage basin,the west of jinghaixian in northern jinnan district and the south of Dagang exhibited a higher ecological risk of heavy metals in the surface sediments, while around the Duliujian river,showed a relatively low risk.(3) Duliujian heavy metals in surface sediments River forms to each state based B4, the share of heavy metals in sediments of various forms of the average ratio of the order of: B4> B3> B2> B1, sediment risk assessment index, Cd overall risk is moderate, there is some kind of a low point of ecological risk; Cu, Cr underlying risk does not exist; Ni, Pb overall a low ecological risk; most of Zn in the low risk, there is a moderate risk of individual samples ecological region. Correlation analysis showed, Sediments B3 state Cd, Ni, Pb and Zn and sediment organic matter content was positively correlated, while Zn, Cd showed a significant correlation at P <0.01 level. |
PDF Full Text Request