Adsorption or desorption of dissolved constituents in liquids and apparatus therefor

The invention relates to a method for adsorbing, on solid adsorbent particles, constituents dissolved in liquid or for desorbing (extracting), from solid desorbent particles, soluble constituents in liquid. The said constituents will often be organic in nature, but inorganic components, in particular heavy metals, are not excluded. To adsorb, on solid adsorbent particles, constituents dissolved in liquid, or to desorb (extract), from solid desorbent particles, soluble constituents in liquid, in a container a packed bed formed from granular material is mixed with adsorbent particles or desorbent particles smaller than 200 m, said bed moves downwards by virtue of gravity, said liquid is passed upwards through the bed by means of a pressure differential, the said dissolved constituents being adsorbed on the solid adsorbent particles or the said soluble constituents being extracted from the desorbent particles.