Abstract: The invention relates to a water treatment method with a view to purifying the same or making it drinkable, characterised in that the method includes the following steps: a step of injecting powdered activated carbon (PAC) into said water in order to obtain a water to be treated/PAC mixture; a step of feeding said water to be treated/PAC mixture into a contacting agitated area in order to obtain an agitated water to be treated/PAC mixture; a step of filtering said water to be treated/PAC mixture within a membrane filtration unit in order to produce treated water and a PAC-rich concentrate; a step of recirculating said PAC-rich concentrate upstream from and/or within said agitated area, the PAC concentration of said mixture ranging from 1 to 10 g/l; wherein said water to be treated/PAC mixture is maintained in said agitated area for a contact duration of between 2 and 20 minutes; and the method further comprises an ozonation step of the water to be treated that comprises injecting ozone in the water to be trea