Treatability of Paper Mill Effluent at Elevated Temperatures Using Mesophilic Bacteria in a UASB Continuous Flow Reactor, 1990 Environmental Conference Proceedings

Stone Container Corporation operates a recycled paper mill at York, Pennsylvania. The mill discharges effluent water with temperatures averaging 105°F (40.6 degrees C) -Short term excursions (duration time less than one hour) to temperatures averaging 116 degrees F (46.7 degrees C) are seen daily.

The mill is installing a high rate UASB (Upflow Anaerobic Sludge Blanket) system to treat its effluent stream. Long term exposure to temperatures in excess of 102 degrees F(39OC) conventionally has been considered unacceptable to the anaerobic bacteria in a mesophilic system. However, recent experiments have indicated the ability of the anerobes to successfully function when temperatures are maintained at 110.3OF (43.5 degrees C).

A 10-liter continuous flow reactor was used to treat mill effluent for a period of 3.6 months. During this time the incubation temperature was; maintained at 43.5°C with a long term excursion of 10 days at 46 degrees C and a short term excursion of 2 days, also at 46 degrees C.

Stone Container hoped to operate its anaerobic wastewater treatment system at elevated temperatures and eliminate using an effluent cooling tower. The purpose of this paper is to discuss the feasibility of that proposal and the results of that study.