Speciation Analysis And Distribution Of Heavy Metals In Sediments From Xiaoqing River In Jinan City

Xiaoqing River is the only road to water transfer schemes of the east route project of South-to-North Water Transfer, so the conditions of water quality in Xiaoqing River have important influences on this water transfer. In this thesis, sediments from Jinan period of Xiaoqing River were investigated. Though the microwave digestion and BCR successive extraction.content, total amount and speciation of heavy metals were analysed systemically. Existing form and frictional distribution characteristics of Zn, Cu, Cr, Ni, Cd and Pb, as well as leaching results of Cu and Zn in sediments with Citric acid and Tartaric acid were explored. The results were as follows:1. The results showed that the content of Zn, Cu, Cr, Ni, Cd, and Pb in Huanxiangdian sampling point, Damatou sampling point and Xinfengzhuang sampling point was more than that in control point. On the basis of index of geoaccumulation, Damatou sampling point and Xinfengzhuang sampling point were less polluted by Zn, Cu, Cd, Ni and Pb, and Damatou sampling point was polluted seriously by Cr, which achieved moderate pollution.2. According to speciation analysis, the content of heavy metals from different forms was various, content of Zn was higher in each forms, while Ni, Cd and Pb were dominated by residual fraction in all samples, and content of Cu varied considerably in each forms. Base on frictional distribution characteristics, the reductive fraction forms of Zn、Cu、Cr、Cd、Pb and Ni increased from Mulizhuang sampling point to Damatou sampling point, then gradually decreased from Xinfengzhuang sampling point. There was no obvious regularity for other existence forms in frictional distribution. 3. Based on the bioavailability of heavy metals, the proportion of active fraction of Zn, Cu, Ni, Cd was higher, and the potential harm to the environment was larger. The active fraction of Pb in each sampling point was low, but its content was higher in sediments. Besides, Pb can be enriched in organism and can cause serious damage to humans, so the harmfulness of Pb was also bigger. The active state content of Cd was higher in Damatou Sampling points, indicating that there may be emissions source.4. The extracting results of Zn and Cu in sediments by tartaric acid and citric acid were studied and the results showed that there was a positive correlation between the extracting amount of Zn and Cu in sediments and concentration of tartaric acid and citric acid, in some concentration ranges; and the leaching effect of Zn and Cu by citric acid was more efficient that by tartaric acid.