Topic background - Aquifers form a major source for drinking water production. However, the
groundwater quality is threatened by anthropogenic pollutants, periods of drought, saltwater
intrusion, and interference from other underground applications. Geohydrological and reactive-
transport models help to predict how these threats play out over time and distance, and to evaluate
possible mitigation strategies. However, the power of these models is limited by the heterogeneity
of the underground and the diffuse nature of the threats. Distributed measurements could be used
to inform these models and make them more accurate. Recent research showed the potential of
fibre optics based sensors, especially Fibre Bragg Grating (FBG). FBGs are individual sensors
engraved in a fiber optical cable that reflect a particular wavelength. This reflection is affected by
bending, stretching or compression of the cable. Fibre optical cables with FBGs can be installed
vertically into the subsurface and provide continuous high-resolutions real-time information about
Research challenges - The challenge for subsurface distributed sensing is to measure without
introducing electrical wires, electrodes and/or potentially harmful materials into the aquifer, as this
would severely complicate the installation, robustness and safety of the sensor. This challenge can
be overcome by making use of the FBGs, since these sensors do not rely on electronic circuits or
electrochemical measurements. Two novel water quality sensing capabilities will be developed:
principle will be used to develop a Refractive index sensing optical cable.
chemical changes, e.g. materials can swells or shrinks when absorbing a salt. FBG are highly
sensitive to such physical effects. This principle will be used to develop an optical cable with
salt-sensitive coatings for chemical sensing.
Objectives and methodology- This PhD research aims to develop a robust FBG-based water
quality sensor with a long expected lifetime and sufficient sensitivity.
The research comprises the following steps:
1. Design and build a FBG-based refractive index sensor.
2. Identify and test salt-sensitive coatings; testing durability, sensitivity and specificity.
3. Test the FBG-based sensor in a laboratory set-up that mimics the aquifer.
4. Test the FBG-based sensor in the field.
Students’ requirements: MSc degree in the field of applied physics, chemistry or related scientific
discipline. Furthermore, the candidate should have adequate experimental skills and experience
with optics, sensors or electronics. Knowledge in the field of geosciences is useful.
Keywords: Fibre Bragg Grating (FBG) sensors, Aquifer management
Academic supervisor: Prof.dr.ir. Herman L. Offerhaus (Optical Sciences group, University of
Wetsus supervisors: Dr.ir. Martijn Wagterveld (Theme coordinator Sensoring), Dr. Renata van
der Weijden (Senior advisor biogeocheminstry), Dr.ir. Roel Meulepas (Theme coordinator
Only applications that are complete, in English, and submitted via the application webpage
before the deadline will be considered eligible.
Guidelines for applicants: https://phdpositionswetsus.eu/guide-for-applicants/Continue reading
|Title||PhD project - Optics-based distributed sensing for the management of groundwater quality|
|Job location||Oostergoweg 9, 8911 MA Leeuwarden|
|Published||September 6, 2021|
|Application deadline||October 29, 2021|
|Job types||PhD  |
|Fields||Medicinal Chemistry,   Chemical Engineering,   Nanotechnology,   Materials Chemistry,   Organic Chemistry,   Biochemistry,   Analytical Chemistry,   Atmospheric Chemistry,   Catalysis,    and 27 more. Chemical Biology,   Chemical Thermodynamics,   Chemo-informatics,   Electrochemistry,   Environmental Chemistry,   Immunochemistry,   Inorganic Chemistry,   Mathematical Chemistry,   Molecular Chemistry,   Nanobiochemistry,   Nuclear Chemistry,   Organometallic Chemistry,   Petrochemistry,   Photochemistry,   Physical Chemistry,   Phytochemistry,   Polymer Chemistry,   Radiochemistry,   Solid-state Chemistry,   Spectroscopy,   Surface Chemistry,   Theoretical Chemistry,   Thermochemistry,   Applied Physics,   Computational Chemistry,   Synthetic Chemistry,   Nanochemistry  |