Release and stability of water dispersible soil colloids
Environmental colloids from soil clay fraction can be described as water-dispersed particles smaller than two micrometers. They can make up a significant proportion of suspended sediments. They effectively bind organic matter and nutrients. The mobility of water-dispersible colloid (WDC) contributes to soil erosion and possible sequestration of organic matter and other nutrients in subsurface environment. Temperature, hydrodynamic parameters (intensive rain, infiltration water rate) and chemical dispersion parameters (pH, ionic strength, SAR) affect the stability of soil aggregates and the release kinetics of WDC.
The current goal of this research is to investigate, in batch experiments, the physic-chemical conditions for the release of WDC from soil and the stability of WDC suspension. The effects of temperature on the release kinetics of WDC from Tereno soils, under low energy shaking conditions, are studied. The effects of organic and inorganic electrolyte composition effects on the WDC dispersion in Na-, Ca- and mixed Na-Ca system are investigated. Chemical analysis, spectroscopic techniques (UV, fluorescence), physico-chemical methods (photon correlation spectroscopy, microelectrophoresis, gas adsorption technique) and scanning electron microscope are applied for characterizing WDC.
Dr. Jean-Marie Sequaris
Tel. : ++49 2461 61 6751
Tel: ++49 2461 61 1792