Abstract: Sewage sludge and other organic suspensions are prepared for filter press or belt press dewatering by substantially simultaneous treatment with a cationic coagulant polymer and a cationic flocculant polymer. A novel composition comprising a dry blend of the two polymers can then be formed to provide a combined solution for mixing with the suspension.

Abstract: An electrostatic separator for separating or removing materials according to their polarizability which comprises a cylindrical surface having a plurality of closely spaced conductors embedded in an electrical nonconductor with the surface adapted to be rotated about its longitudinal axis in close proximity to the material from which loose particles are to be removed. The cylinder is rotated through successive zones wherein the surface of the cylinder is charged while in close proximity to said material causing the particles to migrate to the surface, then through a zone wherein the surface is oppositely charged so as to repel particles therefrom, and collecting and disposing of the particles removed from the material. This apparatus and method has many applications wherein fibers, dust, contaminants, and the like may be removed from the desired product.