Abstract: This invention relates to a method for processing sludge involving the addition of a lime-based basic agent to a sludge having a first pH value in order to raise the pH to a second value higher than the first one, adding at least one anionic organic flocculating agent that is active at the second pH value, flocculating the sludge, and separating the flocculated sludge between dehydrated sludge and a liquid phase.

Abstract: The invention concerns a method for dehydrating sludge, comprising adding a basic agent to sludge having a pH not more than 8, adding to the sludge at least one organic flocculating constituent, by adding said basic agent, increasing the sludge pH to a value not more than a pH at which occurs degradation of said at least one organic constituent, flocculating the sludge and separating in the flocculated sludge dehydrated sludge from a liquid phase, said basic agent being a magnesian limestone compound of formula xCaCO3,(1?x)[yMg(OH)2+(1?Y) MgO], wherein 0,45:=x=0,75, and 0=y=, the treated sludge having, until after said separation, said value less than a pH at which occurs degradation of said at least one organic constituent.

Abstract: The invention concerns a method for dehydrating sludge, comprising adding a basic agent to sludge having a pH not more than 8, adding to the sludge at least one organic flocculating constituent, by adding said basic agent, increasing the sludge pH to a value not more than a pH at which occurs degradation of said at least one organic constituent, flocculating the sludge and separating in the flocculated sludge dehydrated sludge from a liquid phase, said basic agent being a magnesian limestone compound of formula xCaCO3,(1?x)[yMg(OH)2+(1?Y) MgO], wherein 0,45:=x=0,75, and 0=y=, the treated sludge having, until after said separation, said value less than a pH at which occurs degradation of said at least one organic constituent.