Active management of fluidized beds of activated carbon

A method for treating an aqueous fluid comprising the contacting of the aqueous fluid with a fluidized bed of powdered activated carbon, coagulated and optionally flocculated, and a gravitational separation of the aqueous fluid from the bed of coagulated powdered activated carbon that is optionally flocculated, said method for treating being characterized in that it comprises a management step of the fluidized bed of coagulated, powdered activated carbon, optionally flocculated, said management step comprising:

• (a) an extraction of a fraction of the fluidized bed of coagulated powdered activated carbon, optionally flocculated, in the form of sludge;
• (b) at least one separation of the sludge extracted at step (a) so as to obtain a first fraction and second fraction, the first fraction having an HCl-insoluble value higher by at least 5 percentage points than that of the sludge before separation;
• (c) a re-injection of the first fraction obtained at step (b) into the fluidized bed of coagulated powdered activated carbon, optionally flocculated,
• wherein the contacting of the aqueous fluid with the fluidized bed of powdered activated carbon, coagulated and optionally flocculated, and the separation of the aqueous fluid from the bed of coagulated powdered activated carbon that is optionally flocculated are conducted in a single treatment reactor with powdered activated carbon having up-flow operation, wherein the aqueous fluid containing powdered activated carbon and coagulating agent(s) is fed into the lower part of the treatment reactor, and wherein the first fraction is returned to the bottom of the reactor by means of a pipe or channel.