Phosphorus recycling - Sustainability contribution at the decentral wastewater treatment (RECYPHOS)

Aim of the project is the development of an adsorption module for the selective recovery of phosphate from sewage water. This should be used primarily in small domestic waste water treatment plants. It should be capable of being integrated in new and also in already existing plants and offer complete treatment.

Besides the recycling of phosphate as a fertilizer also the compliance with the requirements of DIN EN 12566-3 for the admission of small waste water treatment plants is an aim of this project. In this standard the Deutsches Institut für Bautechnik (DIBt)defines the process parameter + P for the phosphorous removal. According to this the concentration of phosphorous should be reduced to less than 2 mg/L P to avoid eutrophication of waters.

The research project is divided into three studies.

Study A:

Fundamentals of the adsorptive separation and precipitation of phosphate

Department of Water Chemistry, TU Dresden

Different adsorbents should be tested for their applicability. The adsorption module ought to realize a high and selective loading with phosphate from biologically treated waste water and should be regenerated in a following desorption step. Aim of this regeneration is on the one hand a recovery of adsorption capacity. On the other hand a pure and phosphate rich solution should be achieved. This solution will be used to gain a commercially reusable phosphate product (e.g. Struvite, Apatite).

Study B:

Technical realisation of the recycling process

Department of Water Technology and Sanitary Engineering, BTU Cottbus

The optimized process parameters determined in study A form the basis for the planning of an adsorption module for small plants, the creation of a recycling concept and the planning of the regeneration technology. Another part of this study is the calculation of the profitability of the process for different adsorbents. Also the construction and operation of the regeneration facility will be part of study B.

Study C:

Practical testing of the recycling process in small domestic waste water treatment plants

Bergmann Waste Water Engineering, Penig

In this part of the project field tests will be run to study the practical suitability of the process. There the following aspects will be dealt with

  • Up-scaling and design of the adsorption module for the field tests

  • Implementation of the adsorption module in selected field test plants

  • Performance of the field tests

  • Optimization of operating parameters

  • Evaluation of the field tests.