Method for water treatment by adsorption and filtration on a granular material bed

Abstract

Method for treating water by filtration on a bed of granular material in order to reduce its content in contaminants, said method comprising the steps for: making said water travel in transit in a reactor containing said bed in a upward flow at a speed that does not permit the fluidization of said bed but permits said material to migrate, as and when the filtration takes place, towards the lower part of said reactor, continuously removing a fouled granular material at the foot of the reactor, by means of a piping into which a gas is insufflated, said fouled granular material being constituted by granular material and contaminants adsorbed on said granular material; continuously or intermittently carrying out the physical cleansing of said fouled granular material thus removed, so as to obtain a cleansed granular material essentially rid of said contaminants; reinjecting the granular material thus cleansed into an upper part of said bed; characterized in that the granular material is an adsorbent granular material and in that it comprises: a continuous or intermittent step for the discharging, during the filtration, of a part of the fouled granular material removed at the foot of the reactor; and a continuous or intermittent step for the introduction into the reactor, during the filtration, of fresh granular material in a quantity sufficient to compensate for the part of granular material discharged.