PhD Student Position Understanding and Manipulating Iron and Phosphorus Interactions in Sewage Sludge for Phosphorus Recovery (4.3)


Phosphorus is an essential nutrient and a key component in fertilizers. On the other hand uncontrolled phosphorus discharges via sewage lead to eutrophication of surface water and therefore phosphorus must be removed in sewage treatment plants. Recovery rather than removal would help to create a circular economy and prevent the depletion of finite phosphate resources. Iron salts are commonly used to remove phosphorus from sewage and may also play an important role in the current trend to design net energy producing sewage treatment plants. Recovery of phosphorus from iron containing sludge is however still not possible and a better understanding of the iron and phosphorus interaction in sewage treatment is required to propose better recovery options. 

Research challenge
Our research in line with other researchers has shown that the ferrous iron phosphate mineral vivianite, (Fe2+)3(PO43-)2 x 8H2O is a major FeP mineral in sewage sludge before and after anaerobic digestion. In this project we want to build on this previous research to further understand the formation and growth of this mineral so that we can manipulate the processes in sewage treatment in such a way that we can stimulate phosphorus recovery. A thorough understanding of the versatile iron (redox) chemistry as well as crystal growth processes will help to identify and test possible mechanisms for recovery of phosphorus from ironphosphate components in sewage sludge.

We are looking for a candidate with an MSc degree in the field of (bio)chemistry or related disciplines with excellent experimental skills. Knowledge of sewage treatment processes is useful. 

Our offer
Doing a PhD in the Netherlands takes 4 year.
You earn a salary to make a living.
In year 1 the salary is €30.674, in year 4 €39.214 before tax.
The amount of paid holiday days is 35/year.

The research project is part of the Wetsus research theme Phosphate Recovery.
The following companies are part of the theme: ICL fertilizers, Kemira, STOWA, water authority Brabantse Delta, Oosterhof Holman. 

Promotor: M.C.M. van Loosdrecht, TU Delft, Environmental Biotechnology Group.
Promotor:  Prof.dr. G.J. Witkamp, TU Delft, Environmental Biotechnology Group. 

Wetsus supervisor: Leon Korving

For more information contact Leon Korving:

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* Salary has been converted at the prevailing rate on the date placed