A method and device for treating sludge and slime to enable reuse in soil upgrading and in building material systems. Hydrophilic sludge and slime having a water content not less than 70% are continuously treated in a manner which enables colloid removal, dehydration, oxidation, sanitation, stabilization, mineralization, filtration and porosification. The device for treatment includes a hollow caisson traversed in the longitudinal direction by the treated product and provided with at least an intake for the product to be treated and at least an outlet for the treated product.