| With the rapid development of urbanization and industrialization in our country, the river is influenced more and more frequently by human activities,and the river heavy metal pollution is more serious than before. Pujiang county is the largest crystal glass industry gathering area in China, due to the unreasonable development, caused great pollution in Puyang river basin.For resoring the normal functions and ecological envionment of the river, Pujiang County carried out sediment dredging in Puyang river basin(Pujiang county city) in 2014.In order to reflect the Puyang river content of heavy metal in before and after dredging sediment and riparian zone soil, collected 50 soil and sedimen samples in six river, and 64 ecological dredging stations samples, then measured As, Cr, Ni, Cu, Zn, Pb in soil and sediment, spatial distribution and correlation analysis, and then the cumulative index excluting the Nemerow index, the Index of Geoaccumulation and the Potential Ecological Risk Index.using this three evaluation methods comprhensive evaluated the situation of pollution about before and after dredging sediment and riparian zone soil in every river. determine whether presence of harmful heavy metals in the waste residue of crystal, and whether it is related to the content of heavy metal with Puyang river basin Soil and sediment, analyze the sources of pollution, and finally to the existence of heavy metal pollution soil and sediment of Puyang river basin, puts forward prevention and control measures.The results of the study showed that:(1) As and Cr are two main types of heavy metal in the Crystal residue which has extremely strong ecological harm, especially As for the main pollutants, need to unified recycle the waste of crystal.(2) The sediment before dredging in Puyang river basin, heavy metal content of each section of sediment is consistent, and heavy metal content is high, and As is the highest degree of enrichment of metals.After dredging, heavy metals in soil and sediment in Puyang River watershed is still a certain degree of concentration of heavy metals, but significantly lower than the heavy metal content in the sediment before dredging. Dredging has obtained the certain effect, but the effect of dredging inconsistent; Soil and sediment accumulation degree of heavy metals is consistent, As is the highest degree in sediment and soil, are greatly influenced by human.(3) Huanglong and Xixi were the riparian zone of heavy metals in soil and sediment accumulation of heavy metals in the highest level of the river, Xixi sediment dredging is not good, need to increase the depth of dredging, especially in the industrial park and each river estuary,Huanglongxi riparian zone can planting soil arsenic-rich plants to reduce the content of As.. Puyang river and Liwuxi is the lowest degree of heavy metal enrichment in the whole river basin and the dredging effect is better than other rivers.(4) In addition to Ni, Puyang river basin soil and heavy metals in the sediment are generally higher than the background value in Jinqu basin, The area of high content of As and Pb mainly concentrated in two industrial park, high content area of Cr and Zn mainly concentrated in the estuary; sources of heavy metals in sediment before dredging in Puyang River have diversity of characteristics, it showed some of the integrated complex pollution; As and Pb in sediment and soil are relevant, they may come from the same sources.(5)After dredging the sediment pollution in Puyang River was reduced, the ecological harm was reduced, the Xixi and Huanglong rivers were more worse pollution of soil and sediment, As is the main pollution elements in Puyang River basin soil and sediment. |
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