A critical review of the low sludge production (LSP) process for the pulp and paper industry

The Low Sludge Production (LSP) process concept was initially developed and presented by Lund University and ANOX AB [2,3]. and more recently has been demonstrated full-scale at the Norske Skog AS CTMP mill in Follafuss, Norw ay [4]. LSP activity es low sludge yields by simply controlling the microbi ology of all activated sludge treatment (AST)-like process, in a two-stage biological system. Experimental and full-scale results indicate that the sl udge yield of the LSP process is typically less than one-third of the conve ntional AST process sludge yield. This paper reviews the process concept, c ritically reviews the fundamental biological processes upon which thr proce ss is based. and finally presents operating data from the full-scale system at the Norske Skog mill in Norway.