Technical Bulletin No. 0100: Dewatering of Groundwood Sludge Obtained from the Clarification of Groundwood Mill Effluent for Final Disposal of Sludge and Water

The attached Technical Bulletin was first published in 1957, and reported on the results of a Syracuse University study of thickening and filtration of ground wood sludges after chemical conditioning. The study had been prompted by a literature review on sludge dewatering and bound water removal from hydrogels, also conducted at Syracuse for the National Council by Dr. Ernest Reed. The study indicated that the only effective treatment involved addition of a large dosage of polyelectrolyte. This conditioned the sludge to a point where it dewatered fairly well on a vacuum filter. Since the costs then associated with such treatment were considered high, and since long filter runs did not appear possible with the media then available, the experimental program was redirected toward centrifugal dewatering. This Technical Bulletin is being kept on our active list since it represents an early study of a problem that still confronts us, namely the search for optimal methods of dewatering hydrous sludges generated during pulp and paper manufacturers, or from the treatment of associated effluents.