Abstract:
The granulometric, geochemical and particle-size fractions separate analyses are conducted on the sediments from Oujiang rver, Zhejiang province, China. And the enrichment factor and index of geoaccumulation are conducted to assess the level of heavy metal contamination and its influence factors. The results show that: (1) According to the variations of particle size composition, Oujiang river can be divided into fluvial reach, upper tidal reach and lower tidal reach. The significant difference of the particle-size composition and heavy metal concentration is exhibited in theses reaches. (2) The heavy metals concentration of sediments from fluvial reach are approximate to background value and mainly source from natural weathering process. (3) In lower reach of Oujiang river, the Cu, Cr, Ni and Zn are identified as light to moderate pollution levels, which caused by the intensive economic activities and industrial types in Wenzhou city. (4) The heavy metals concentration of sediments from Oujiang river are significant influenced by the "particle size affect", the fine fractions sediments have relatively higher heavy metals concentration and also affect by the sediments transportation and sediments provenance.