Sedimentation characteristic of soil suspension under condition of different pHs

In order to clarify the influence of pH on the sedimentation characteristic of a soil suspension, sedimentation analyses were performed on 5 soil samples of which pH values were artificially changed by adding sulfuric acid or sodium hydroxide solutions. There exists a liner relationship between the thickness of sediment and the effective depth of soil suspension. Therefore the sedimentation characteristic can be evaluated by the effective depth. Also, settling velocity seems to be dependent on the pH, clay fraction and a kind of main clay mineral. This phenomenon may be induced by the difference of electric charge on surface of soil particles due to the pH of solution.

pH

cohesive soil

sedimentation

suspension