Open Positions

The eutrophication of water bodies caused by the input of nutrients, particularly phosphorus, poses a significant ecological challenge. At the same time, phosphorus is a finite resource that is indispensable for global food production (e.g. in the form of fertiliser). This project, which is part of the graduate research training group WERA, therefore aims to develop a sustainable process for the adsorptive separation and recovery of phosphorus from municipal wastewater treatment plant effluent The adsorbent material is placed in a fixed-bed column, where it selectively separates phosphorus compounds from the effluent. While an ongoing doctoral project focuses on optimising adsorption and developing new materials, this project focuses on the second crucial step: efficient desorption and phosphorus recovery.

The overall goal is to develop an ecologically and economically viable desorption process for phosphorus recovery. Initially, the project will conduct a comprehensive concept study, investigating and evaluating various desorption processes for phosphorus recovery. The focus will be on pH swing regeneration using a flushing solution and an electrodialysis process. The theoretical efficiency, expected costs and environmental impact of these processes will then be compared. Based on these findings, systematic laboratory tests will be carried out in batch and column experiments. Particular attention will be paid to characterising the desorption kinetics and the long-term stability of the adsorbent material over several adsorption/desorption cycles. The experimental data obtained will serve as the basis for developing mathematical process models. This knowledge will then be used to develop a mini-plant system to validate the entire adsorption/desorption process and comprehensively test its performance under real conditions using sewage treatment plant effluent.

Important scientific questions:

• How do operating parameters such as the type and concentration of eluents, flow rates or current density in the case of electrodialytic regeneration affect the desorption process?
• Does electrodialysis offer advantages over conventional desorption using pH swing for regenerating the adsorbent material and recovering phosphorus?
• Is it possible to find a robust adsorption/desorption process that can be operated stably and reliably under real conditions?

You can send your application for this PhD topic to:  erik.vonharbou[at]rptu.de