Abstract
Studies were carried out for the purpose of establishing a method for evaluating the pollution of river sediment by heavy metals, with easiness and good reproducibility. The result of studies were as follows.
1) Variations in the concentration of heavy metals by particle composition of the bottom sediment were examined. As a result, coefficient of variation was found to become smaller as the particle size become smaller. When particle size is less than 0.075mm, the coefficient of variation was reduced to about 10%, and variation by particle size became smaller.
2) As a result of comparison of metal concentrations in primary and secondary sediments in the bottom sediment, variation in the concentration of heavy metal were found to be influenced largely by metal concentrations of secondary sedimentation. Further, the variation in the metal concentrations in primary sediment are small, and these metal concentrations are supposed to form a back ground concentration at respective positions in a sample collection.
3) By comparing the ratio of heavy metals such as Zn ·Cd-1, etc., it was found that characteristics of respective river is possible to find out.
