PhD Student in Environmental Science (Stockholm University)

Department of Environmental Science, Stockholm University The Department of Environmental Science is one of the largest departments at the Faculty of Science. The department consists of four units with more than 170 researchers, teachers, doctoral students, and technical/administrative staff from over 30 countries. Research and teaching focus on chemical contaminants, atmospheric science, biogeochemistry, and (eco)toxicology. Employees are part of a dynamic environment with leading international research. More information about the department can be found on the Department website. The Contaminant Chemistry Unit currently consists of six research groups (Benskin, Cousins, MacLeod, Rahu, Posselt, and Sobek). Our research programs examine the occurrence and behavior of pollutants in the environment and technosphere. Areas of particular interest include the discovery of new contaminants, understanding the physical, chemical, and biological pathways that contaminants follow, and the development of novel tools and techniques for sampling and analysis. We aim to synthesize scientific understanding about the sources, transport, transformation, and bioaccumulation of environmental contaminants into mathematical models that inspire new hypotheses and support environmental decision-making. Project Description Hadal zones—located 6–11 km below the ocean surface—represent the deepest regions on Earth. Limited data suggest that hadal sediments are important repositories for legacy hydrophobic persistent organic pollutants (POPs). The importance of hadal zones as sinks for contaminants with more diverse properties, however, is poorly understood. Emerging evidence suggests that hadal microbial communities may be adapted to degrade halogenated pollutants. This project, entitled “Small but efficient – can hadal sediment microbes degrade persistent chemicals? (Hadal-Degrade)”, will investigate the occurrence of a diverse suite of contaminants in sediments from deep-sea trenches in the northern and southern hemispheres using state-of-the-art mass spectrometric methods. Additionally, lab-based biodegradation experiments in high-pressure chambers will test hypotheses on the influence of hadal microbial diversity on chemical persistence. The project will improve fundamental knowledge on the role of hadal trenches in global contaminant cycling and may open pathways for sustainable bioremediation technologies for contaminated environments on Earth’s surface. Qualification Requirements Applicants must meet general and specific entry requirements for doctoral studies in Environmental Science at Stockholm University. General Entry Requirements: Completion of a second-cycle degree (master’s level), or equivalent of at least 240 higher education credits, of which 60 must be at the second cycle, or equivalent knowledge acquired elsewhere. Specific Entry Requirements: At least 45 credits at the second cycle in one of the natural sciences (Biology, Chemistry, Earth Sciences, Physics, or Meteorology), including a 30-credit thesis project. At least 30 credits in other natural science subjects different from the major. Selection Criteria Candidates will be evaluated based on their capacity to benefit from the doctoral training. Assessment criteria include: Documented knowledge in a relevant field of research. Capacity for analytical and creative thinking. Initiative and independence. Ability to collaborate. Written and oral proficiency in English. Meritorious skills/experience: Experience in liquid and gas chromatography, high-resolution mass spectrometry, ion mobility, trace analysis of environmental contaminants, and suspect/non-target screening. Short-listed candidates may be required to demonstrate problem-solving skills through a practical exercise. Employment Fixed-term employment as a doctoral student according to Chapter 5 of the Higher Education Ordinance (1993:100). Employment period corresponds to full-time doctoral education for four years. Employment may include work with education, research, and administration to a limited extent (maximum 20%). New employment is for a maximum of one year and renewed for a maximum of two years at a time. Stockholm University strives to be a workplace free from discrimination and with equal opportunities for all. Contact For more information, contact: Professor Anna Sobek Phone: +46 8 674 72 30 Email: anna.sobek@aces.su.se Application Apply for the PhD position through Stockholm University’s recruitment system. Attach a personal letter, CV, and requested attachments from the application form. Applicants are responsible for ensuring their application is complete and submitted before the deadline. The instructions for applicants are available at: How to apply for a position. Type of Employment: Temporary position Contract Type: Full time Salary: Fixed salary Number of Positions: 1 Full-time Equivalent: 100% City: Stockholm County: Stockholms län Country: Sweden Reference Number: SU FV-3464-25 Union Representatives: ST/OFR: st@st.su.se Saco-S: saco@saco.su.se Seko: seko@seko.su.se Published: 29 Sep 2025 Last Application Date: 03 Nov 2025 If you apply for this position please say you saw it on Engineeroxy

Department of Environmental Science, Stockholm University

The Department of Environmental Science is one of the largest departments at the Faculty of Science. The department consists of four units with more than 170 researchers, teachers, doctoral students, and technical/administrative staff from over 30 countries. Research and teaching focus on chemical contaminants, atmospheric science, biogeochemistry, and (eco)toxicology. Employees are part of a dynamic environment with leading international research. More information about the department can be found on the Department website.

The Contaminant Chemistry Unit currently consists of six research groups (Benskin, Cousins, MacLeod, Rahu, Posselt, and Sobek). Our research programs examine the occurrence and behavior of pollutants in the environment and technosphere. Areas of particular interest include the discovery of new contaminants, understanding the physical, chemical, and biological pathways that contaminants follow, and the development of novel tools and techniques for sampling and analysis. We aim to synthesize scientific understanding about the sources, transport, transformation, and bioaccumulation of environmental contaminants into mathematical models that inspire new hypotheses and support environmental decision-making.

Project Description

Hadal zones—located 6–11 km below the ocean surface—represent the deepest regions on Earth. Limited data suggest that hadal sediments are important repositories for legacy hydrophobic persistent organic pollutants (POPs). The importance of hadal zones as sinks for contaminants with more diverse properties, however, is poorly understood. Emerging evidence suggests that hadal microbial communities may be adapted to degrade halogenated pollutants.

This project, entitled “Small but efficient – can hadal sediment microbes degrade persistent chemicals? (Hadal-Degrade)”, will investigate the occurrence of a diverse suite of contaminants in sediments from deep-sea trenches in the northern and southern hemispheres using state-of-the-art mass spectrometric methods.

Additionally, lab-based biodegradation experiments in high-pressure chambers will test hypotheses on the influence of hadal microbial diversity on chemical persistence. The project will improve fundamental knowledge on the role of hadal trenches in global contaminant cycling and may open pathways for sustainable bioremediation technologies for contaminated environments on Earth’s surface.

Qualification Requirements

Applicants must meet general and specific entry requirements for doctoral studies in Environmental Science at Stockholm University.

General Entry Requirements:

Completion of a second-cycle degree (master’s level), or equivalent of at least 240 higher education credits, of which 60 must be at the second cycle, or equivalent knowledge acquired elsewhere.

Specific Entry Requirements:

At least 45 credits at the second cycle in one of the natural sciences (Biology, Chemistry, Earth Sciences, Physics, or Meteorology), including a 30-credit thesis project.
At least 30 credits in other natural science subjects different from the major.

Selection Criteria

Candidates will be evaluated based on their capacity to benefit from the doctoral training. Assessment criteria include:

Documented knowledge in a relevant field of research.
Capacity for analytical and creative thinking.
Initiative and independence.
Ability to collaborate.
Written and oral proficiency in English.

Meritorious skills/experience:

Experience in liquid and gas chromatography, high-resolution mass spectrometry, ion mobility, trace analysis of environmental contaminants, and suspect/non-target screening.

Short-listed candidates may be required to demonstrate problem-solving skills through a practical exercise.

Employment

Fixed-term employment as a doctoral student according to Chapter 5 of the Higher Education Ordinance (1993:100).
Employment period corresponds to full-time doctoral education for four years.
Employment may include work with education, research, and administration to a limited extent (maximum 20%).
New employment is for a maximum of one year and renewed for a maximum of two years at a time.

Stockholm University strives to be a workplace free from discrimination and with equal opportunities for all.

Contact

For more information, contact:
Professor Anna Sobek
Phone: +46 8 674 72 30
Email: anna.sobek@aces.su.se

Application

Apply for the PhD position through Stockholm University’s recruitment system. Attach a personal letter, CV, and requested attachments from the application form. Applicants are responsible for ensuring their application is complete and submitted before the deadline.

The instructions for applicants are available at: How to apply for a position.

Type of Employment: Temporary position
Contract Type: Full time
Salary: Fixed salary
Number of Positions: 1
Full-time Equivalent: 100%
City: Stockholm
County: Stockholms län
Country: Sweden
Reference Number: SU FV-3464-25