Phosphorus Control and Reduction at a Corrugating Medium Mill, 1998 Environmental Conference Proceedings

The effluent total phosphorus concentration from this corrugating medium mill averaged greater than 3 mg/L; whereas, the mill’s discharge permit contained an effluent total phosphorus limitation of 1.0 mg/L. Therefore, a comprehensive phosphorus minimization study was conducted. The study characterized phosphorus sources and evaluated phosphorus minimization and end-of-pipe control options for reducing phosphorus discharges. In-mill phosphorus minimization options were identified, but generally determined to be impractical or ineffective. Evaluation of end-of-pipe control focused on biological phosphorus removal, metal salt precipitation, and effluent filtration. Metal salt precipitation was found to be the most cost-effective treatment technology. Bench-scale tests were conducted with several metal salts. However, the testing demonstrated that required metal salt dosage levels were 2 to 5 times those required for similar applications at municipal wastewater treatment plants. Corresponding unit costs were found to range from $63 to $82 per pound of phosphorus removed, more than an order-of-magnitude higher than for other dischargers in the State that had implemented phosphorus reduction programs. Based on these findings, the mill applied for an alternate effluent limitation of 4.0 mg/L.