duration: 04/2014 - 04/2016, extension: 02/2017 - 07/2017
projectduration at TUK: 02/2017-11/2017
accomplishment: rewa
processor: Prof. Dr.-Ing. Heidrun Steinmetz, Dipl.-Ing. Kathrin Münch
funding: Umwelttechnologieforschung der Baden-Württemberg Stiftung gGmbH
description
Phosphate is a strategically important raw material that will become increasingly important in the future. Especially in agriculture, phosphate is needed as a non-substitutable fertilizer. Phosphate deposits containing raw material with acceptable purity are running short. Products that are contaminated with highly toxic heavy metals or radioactive elements are increasingly being ciculated as fertilizers. In addition to phosphate from the primary deposits, the substance should therefore increasingly be recycled from secondary sources. This also supports the political goal of reducing the country's import dependency on the few nations possessing phosphate. Therefore, processes must be developed to recover phosphate from different sources (Resource Protection Programm of the Federal Government, 2013). The subject of the project "SuPaPhos" is the technical implementation of the novel approach of phosphate recovery on half-scale from laboratory scale. The process developed in the previous project removes phosphate ions dissolved in the wastewater treatment process by means of magnetically separable ion exchange particles. There have to be no previous phosphorus elimination in the earlier stages of treatment to ensure the optimal recovery of phosphorus. These are micrometer-sized (20-25 μm) composite particles of nanometer-sized, superparamagnetic magnetite particles encased in a matrix of SiO2. The surface of the particles is occupied by a phosphate-selective ion exchanger. The particles are freed from the phosphate load in a regeneration solution and reused. In the regeneration solution, phosphate is enriched, which is then available for reuse. The laboratory-scale proven process is now to be tested in a large-scale trial (a total of 6.3 m³ of wastewater will be treated in 15 cycles). (For more information, please visit the website of ISWA, University of Stuttgart) As part of the joint project, the University of Kaiserslautern has investigated the integration of the process into existing wastewater treatment plants. Process engineering concepts for large-scale implementation were presented and the implementation of these in conventional wastewater treatment plants was shown. The effects on a conventional wastewater treatment plant through the implementation of the SuPaPhos technology were qualitatively and quantitatively described. Finally, balancing the particles and phosphorus inside and outside the process revealed the potential of this Technology.