SIMULATION OF WHITE WATER MANAGEMENT STRATEGIES FOR AN INTEGRATED NEWSPRINT MILL

New environmental regulations are forcing the pulp and paper industry to invest in effluent treatment systems. For integrated newsprint mill s, inplant measures help to reduce Suspended solids and effluent flow, which reduces the cost of the additional external treatment system. T his paper describes the results of a systematic analysis of white cate r management strategies in a modern TMP newsprint mill. This analysis was performed using PAP MOD, a process simulation software package dev eloped by Paprican. Four possibilities to improve further the closure of the white-water system of this already efficient mill were identifi ed. Their implementation at the mill could reduce fibre loss by up to 7.5 adt/d and fresh water use by up to 1.700 m(3)/d. Occasional overfl ows from white water tanks were found to represent a major proportion of sewer losses.