Submitted to: Frontiers in Wastewater Treatment and Modeling. Book Series: Lecture Notes in Civil Engineering
Publication Type: Book / Chapter
Publication Acceptance Date: 4/5/2017
Publication Date: 5/5/2017
Citation: Vanotti, M.B., Dube, P.J., Szogi, A.A. 2017. Recovery of ammonia and production of high-grade phosphates from side-stream digester effluents using gas-permeable membranes. Frontiers in Wastewater Treatment and Modeling. Book Series: Lecture Notes in Civil Engineering. 4:13-17. doi:10.1007/978-3-319-58421-8_2.
Technical Abstract: Phosphorus recovery was combined with ammonia recovery using gas-permeable membranes. In a first step, the ammonia and alkalinity were removed from municipal side-stream wastewater using low-rate aeration and a gas-permeable membrane manifold. In a second step, the phosphorus was removed using magnesium chloride and reduced amounts of alkali. The side-stream wastewater contained 730 mg ammonia-N per liter, 140 mg phosphorus per liter, and 2900 mg alkalinity per liter. The process recovered approximately 79-93 percent (%) of the ammonia and 80-100% of the phosphorus. Surprisingly, the phosphates produced were very-high grade (42-44% P2O5) with a composition similar to the bio-mineral newberyite. However, lower grade phosphate products (27-29% P2O5) were produced whenever the N recovery step was bypassed or carbonate alkalinity was added. Therefore, removal of ammonia and alkalinity are important considerations for production of very-high grade phosphate product.