(EN) A method of treating liquid containing at least one contaminant including mixing precipitant chemical with the liquid to cause a precipitation reaction and produce a precipitant, introducing the precipitant and the liquid into a clarification device, mixing activated silica with the precipitant and liquid to cause a flocculation of the precipitant, separating the liquid from flocculated precipitant, and introducing the liquid into a membrane treatment device to cause a reduction of flocculated precipitant from the liquid.