Sludge dewatering process and vehicle for use in such process

Abstract

A process for economical air drying of aqueous sludge, and a vehicle which may be used in practicing such process. The surface of a pool of sludge, such as in a sludge lagoon, is systematically agitated to break up the dry crust and to bring wet sludge to the surface for more rapid removal of water by evaporation and to form a dry upper layer of substantial thickness. The drier surface material is skimmed off the surface and either harvested directly or shifted laterally to provide an inclined surface on the lagoon so as to facilitate drainage of surface water, such as from precipitation. The dry surface sludge is harvested from the lagoon either after systematic shifting of the dry surface sludge to one side of the lagoon, or by transporting of the dry sludge through a conduit to the side of the lagoon, or by loading of the sludge into a receptacle of a stirring/harvesting vehicle for periodic delivery to the side of the lagoon. The vehicle which may be employed in practicing this process is provided with buoyant propelling wheels which penetrate the sludge but are sufficiently buoyant to support the rest of the vehicle above the surface of the lagoon, and mechanism for shifting or harvesting the sludge is mounted on the forward end of the vehicle. In supporting the vehicle and propelling it across the lagoon, the wheels effectuate agitation of the sludge in the lagoon.