Full Scale Application of Ozone for Bulking Control at a Pulp &Paper Facility

Bulking and foaming problems are known to be the primary cause of the failure of activated sludge systems. This paper is focused on the application of ozone for bulking control at full scale in a pulp and paper facility which treats about 350 m3/hr of flow. The goal of ozonation was to reduce and to reliably maintain DSVI (ml/g) at target values that enable good settling. Detailed microbiological analysis of the sludge indicated that the bulking problems were primarily due to two filamentous species – Nostocoida Limicola and Eikelboom Type 0914. Following some modifications in the plant process flows, a new filamentous species, Type 1701 appeared. Sludge ozonation enabled as much as 50% of the filaments present in the system to be eliminated