Method of dewatering material containing solid matter and bound and unbound water

Abstract

Abstract A sludge, or other material containing solid matter and bound and unbound water, is dewatered by first pretreating the sludge with an alkaline composition, admixing the pretreated sludge with an amine having an inverse critical solution point with water, lowering the temperature of the resulting slurry below the inverse critical solution point, and separating the solid matter from the resulting single phase liquid. The single phase liquid is then heated to a temperature above the inverse critical solution point to form an amine phase and a water phase, after which the water phase is separated from the amine phase. The pretreatment of the sludge with the alkaline material substantially reduces the amount of residual amine carried over into the solid and water products. Effective alkaline materials include lithium, sodium, potassium and calcium hydroxides and the salts of relatively strong bases and weak acids, such as potassium phosphate.

Inventors

• 👤 Robert K Ames

Bibliographic Details