Evaluation of Sulfur Source Emission Around the Wastewater Treatment of a Kraft Mill, 1998 Environmental Conference Proceedings

Robert Dufresne

Isabelle Laroche

DOMTAR Papers, Windsor Business Center

After experiencing odour problems around the wastewater treatment process, the Windsor fine paper mill decided to start a complete sulfur compounds characterization of the effluent entering the wastewater treatment process. The study also included an evaluation of lost and produced sulfide in each step of the process. The results of the first part of the study demonstrated the anaerobic generation of H2S, as a source of TRS in the effluent in both settling basin and in the quiescent zone of the lagoon. Inside the sludge dewatering building, the highest concentration of sulfur compounds was measured in the raw effluent tank and above the flotation units inlet. Some actions were rapidly taken. Biosludge accumulation in the settling basin was removed and the lagoon air blowers were optimized. A modification permitted to recirculate the biosludge directly to the lagoon instead of to the settling basin. The results obtained from a new series of analyses demonstrated that the anaerobic generation of H2S was reduced. Furthermore, the release of TRS at the cooling towers and in the sludge dewatering building decreased. The foul condensates still remain the most significant source of sulfur of the wastewater treatment process.