A system for formation treatment of sludge in which an endless belt screen forms an electrode which extends over a portion of its path into the fluid sludge and is juxtaposed with another electrode therein so that the applicaton of an electrical potential across the electrodes results in the formaton of a consolidated and partly dewatered sludge deposit upon the screen electrode. The latter then carries the deposit to a drying chamber and preferably thereafter to an incinerator chamber in which the sludge deposit is incinerated alternatively, the dry sludge layer can be removed.