The Netherlands Organisation for Scientific Research (NWO) Domain Applied and Engineering Sciences (AES), recently granted a four-year research program RUST within the context of the NWO program. 'Closed cycles - Transition to a circular economy'. RUST focuses on Re-USe of Treated effluent for agriculture, and is a collaboration between Wageningen University (WU Department of Soil Physics and Land Management) and Utrecht University (UU Copernicus) and partners knowledge institute KWR and company KnowH2O. The program RUST involves 2 PhD students (WUR and UU Re-use of Treated Waste Water/effluent (TWW) for sub-irrigation in agriculture serves the dual purpose of supplying water to crops and diminishing emissions of Contaminants of Emerging Concern CECs to surface water. The aim is to investigate re-use at two field sites with climate adaptive drainage where TWW is infiltrated by sub-irrigation to store water until summer, when the crop needs it. Sub-irrigation/drainage cycles are optimally designed and operated, to supply water, raise groundwater levels towards the root zone, limit CEC exposure to crops and decrease their emission to surface water. Operation should take the complicated 3 dimensional flow and transport routes into account. Seasonally, these routes can be highly dynamic, as they are also affected by erratic weather.

Treated waste water (TWW) is often contaminated with compounds such as nutrients, persistent and mobile organic compounds (PMOCs), a range of emerging contaminants including pharmaceuticals, day-care products and hormone disrupting compounds, Depending on the origin of TWW. Re-use of TWW may prevent drought and increase crop yields, but may also reduce emissions of contaminants to open water, if contaminants degrade in the subsoil. We aim to characterize groundwater flow and compound dispersion in the subsurface with physical and chemical monitoring, and complex physical modelling. By manipulating the injection of TWW, subject to erratic weather and the crop water and nutrient demand, we investigate the spreading of undesirable compounds that may adversely affect the crop/vegetation, deeper groundwater and surface water. Flow, CEC transport and degradation, and the supply of water and CECs to the root zone are monitored at both field sites by a PhD student of Wageningen University and one of Utrecht University. For this purpose, also soil samples are characterized physically and chemically. Transient modeling of the heterogeneous field sites aims at interpreting the monitoring data and supporting an integrated risk assessment for soil, groundwater, surface water and food.

We are searching for a hydrologist, (soil) physicist, or physical geographer, with experience in numerical modelling of water flow and contaminant transport and software as R, Python, Matlab. Sufficient background in biogeochemical interactions as relevant in the subsurface and interest in experimental research is recommended. Good writing skills and communication capabilities for presenting results and to interact with stakeholders and end-users (farmers and water managers) are needed.

We offer a fulltime employment (38 hours a week) as PhD candidate within the Soil Physics and Land Management Group for 18 months with a possible extension of 30 months after a positive evaluation. The gross salary will increase from € 2.222,= in the first year up to € 2.840,= per month in the fourth year (based on fulltime employment). In addition, we offer a holiday bonus of 8% and an end-of-the-year bonus of 8.3% of your annual salary.

Wageningen University & Research

Wageningen University & Research
Delivering a substantial contribution to the quality of life. That's our focus - each and every day. Within our domain of good and safe food & food production, food security and a healthy living environment, we search for answers to issues affecting society - such as sustainable food production, climate change and alternative energy. Of course, we don't do this alone. Every day, 5000 people work on 'the quality of life', turning ideas into reality, on a global scale.

The Soil Physics and Land Management group of Wageningen University is involved in teaching for bachelor and masters programs related with the natural soil and groundwater environment, crop and primary production, and pollution studies. Our research, predominantly of the Ecohydrology subgroup, is dedicated to mathematical, physical, chemical and ecological aspects of transport of dissolved substances (solutes) in water in the unsaturated soil and in groundwater. For these tasks, advanced laboratories and software are used.