Counter-current adsorption filters for the treatment of liquids and a method of operating the filter

A method of operating a counter-current adsorption filter column or an ion exchange column wherein

• (a) different adsorbents or ion exchangers are in a corresponding number of different chambers in the column defined by horizontal subdivisions;
• (b) adsorbents or ion exchangers which are regenerated with different regenerating agents are present in adjacent chambers;
• (c) the chambers--with the exception of the topmost chamber of the column--are equipped with a liquid drainage system which is located below the device which is permeable to liquid and forms the upper boundary of the chamber, and which is embedded in a layer of inert material;
• and
• (d) the amount of adsorbent or ion exchanger (in % by volume) in the individual chambers is 50 to 98% of the free volume of the chamber,
• the method comprising
• (i) in the loading phase passing a stream of liquid to be treated from the bottom upwards through the chambers, and
• (ii) in the regenerating phase, chamber by chamber introducing a regenerating agent and wash water into the top of each chamber to be regenerated, and removing the spent regenerating agent and washing water through the liquid drainage system of the chamber below simultaneously with a stream of water which flows in counter-current to the stream of the spent regenerating agent and washing water and which is being passed from the bottom upwards through this very chamber below.