Validating the Reliability of Cloth Media Filtration to Achieve an Effluent Total Phosphorus Less Than 75 μg/L

Increasingly strignent total phosphorus effluent standards are driving water resource recovery facilities to add tertiary treatment steps including filtration to their process. Cloth media filtration is commonly used for this application. Recent advances in this technology have improved the removal of fine particles, which in turn improves the removal of particulate phosphorus and reduces the effluent total phosphorus.Three pilot studies were conducted to assess the ability of cloth media filtration to consistently meet effluent total phosphorus of 75 μg/L. This objective was met in all three studies. Each site required a unique recipie of metal salt, polymer, and flocculation to achieve these limts. Three keys for success were identified to achieve these ultra low levels. These keys were:Maintain a consistent filter influent total phosphorus concentration.Track phosphorus speciation carefullyPrecise laboratory measurement