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PhD

We forge the researchers and developers of the future. Our PhD students have high academic ambitions and deliver high-quality results for both the private and the public sectors. Our primary focus is on applied research, and we have strong collaboration with industry, because we listen to the core questions from industry regarding biotechnology and chemical engineering, and we develop solutions.

On this page, you can meet some of our PhD student and read about their projects.


Engineer from AU honoured for her work on developing batteries for storing green energy

Kristina Wedege, PhD and MSc in Engineering, received the 2019 Aarhus University Research Foundation PhD Award. Kristina is happy that others can see the value of her work on developing greener solutions for renewable energy storage technologies.

If Denmark is to run on renewable energy in 2050 as planned, we need to be able to store solar and wind energy. This is why one of the hottest topics today is to find suitable technological solutions to this challenge, and this is precisely what chemical engineer Kristina Wedege set out to do in her PhD project for which she will now receive the prestigious Aarhus University Research Foundation PhD Award.


Lactose derived metabolites as determinants in the response of intestinal microbiota to ingested fermented dairy products

Fermented dairy products are regularly consumed worldwide and most often contain lactose and the fermentation product lactate. Upon ingestion, they reach the small intestine, which is colonized by a significant number of bacteria. Here, undigested lactose can be transformed to lactate, and some specialist bacteria may transform lactate to short chain fatty acids, small molecules which are considered beneficial for health. Due to difficulties in obtaining samples from the small intestine, only little is known about the interplay between lactose, lactate and the intestinal bacteria and the effect on human health.

In this project we will establish an in vitro Small Intestinal MICrobiota model (SIMIC) to characterize lactose/lactate dependent interactions of the small intestinal microbial community. This will be done by assembling different consortia of representative bacterial species of the small intestine microbiota to then assess the effect that lactose/lactate has on them.

Furthermore, in collaboration with the LAMETA project, we will assess the possible relation between increased dosage of dietary lactate and higher short chain fatty acid level in humans ‘stool samples.

Considering both of its parts, this project will enable the study of the effect of oral lactose/lactate on the intestinal microbial community and the fermentation profile of these metabolites in different districts of the human gut.

ABOUT THE PROJECT


Project title: Lactose derived metabolites as determinants in the response of intestinal microbiota to ingested fermented dairy products

PhD student: Alex Berretta

Project start: May 2024

Main supervisor: Clarissa Schwab

Research section: Industrial Biotechnology


Characterization and engineering of monooxygenases for the use in multi-enzyme/whole cell catalytic production of short-medium chain diols and diacids

Our project aims to innovate in the field of plastic recycling by leveraging the capabilities of Cytochrome P450 enzymes for the bioconversion of recycled hydrocarbons into biodegradable plastic substitutes. Here's an overview of our approach:

Screening and characterization of CYP153 orthologs capable of hydroxylating and oxidizing medium length alkanes into α, ω-diols and diacids.

Protein engineering of selected CYP153 enzymes to fine-tune their specificity and activity towards targeted substrates through computational methods and machine learning algorithms, to predict and implement beneficial mutations.

Scale-up of CYP153 is conducted in large-scale bioreactors, with a focus on enhancing efficiency, cofactor regeneration, and fine-tuning reaction conditions to maximize yields.

Our project stands at the intersection of biotechnology and environmental engineering, aiming to establish a scalable, efficient pathway for converting plastic waste into valuable biodegradable materials. Through collaboration with industrial partners, we seek to bring this technology to a level where it can make a significant impact on waste management and recycling practices, contributing to a more sustainable circular economy.

ABOUT THE PROJECT


Project title: Characterization and engineering of monooxygenases for the use in multi-enzyme/whole cell catalytic production of short-medium chain diols and diacids

PhD student: Frederik Vig Benfeldt

Project start: February 2024

Main supervisor: Bekir Engin Eser

Co-supervisor: Zheng Guo

Research section: Industrial Biotechnology


C1 to Cn: Rewrite energy path by enabling autotropic growth of Saccharomyces cerevisiae on CO2

Carbon fixation by autotrophs is the major biochemical gateway to the organic world. The utilization of one-carbon compounds such as CO2 and methane (accounting for 76% and 16% of total GHG emission), have been recently drawing attention as a low-cost, abundant feedstock for biochemical production. The project aims to create a synthetic autotroph Saccharomyces cerevisiae, allowing it to utilize methanol and CO2 for biochemical synthesis of alka(e)nes, reducing dependence on traditional feedstocks like sugars. This not only addresses climate change by transforming CO2 but also enhances sustainability by repurposing one-carbon compounds.  Our objectives include engineering S. cerevisiae into a more sustainable platform where the recombinant S. cerevisiae can use methanol as ATP and reducing power source, and CO2 as carbon source for biomass production. The new CO2-pixation pathway should enable S. cerevisiae to grow with CO2 as sole carbon source, and further provide flux of acetyl-CoA for source for fatty acids and alkanes synthesis as useful products.

I have a bachelor’s degree in biotechnology and a master’s degree in Biological and Chemical Engineering from Aarhus University (2018-2023). I did my master thesis and my bachelor project in Prof. Zheng Guo’s group where I cloned and characterized a novel bacterial laccase and proved its ability to degrade PE plastic and various textile dyes.  

ABOUT THE PROJECT


Project title: C1 to Cn: Rewrite energy path by enabling autotropic growth of Saccharomyces cerevisiae on CO2

PhD student: Thea Jess Plesner

Project start: November 2023

Main supervisor: Zheng Guo

Co-supervisor: Bekir Engin Eser

Research section: Industrial Biotechnology


Circular Fuel Supply for Air Transport via Negative Emission Hydrothermal Liquefaction (CIRCULAIR)

Reducing emissions in aviation is unavoidable in order to reach the Paris goals and can be supported by e. g. sustainable aviation fuels (SAF). Hydrothermal liquefaction (HTL) is a thermochemical processing technology that has been receiving increased interest to produce sustainable fuels from biomass. HTL bio‑crude is the desired product which can be upgraded and therefore be used as drop‑in fuel or SAF. The ambition of the Horizon Europe project CIRCULAIR is to produce carbon negative aviation fuels from manure and straw. A potential treatment method for the HTL process water (PW) is Wet Oxidation (WO) –suitable for wastewater streams with high organic load at similar process conditions like HTL. During the oxidation of the soluble organics in PW, CO2 is formed which can be combined with the CO2 stream produced in the main HTL process. The current PhD project has a key role in the overall CIRCULAIR process chain by investigating the WO process of HTL‑PW in continuous flow reactor in detail. The focus will be on heat integration of HTL and WO, sustaining both systems in autothermal mode with the excess oxidation reaction heat. Furthermore, HTL‑WO gas phase composition will be analyzed to utilize it with hydrogen from electrolysis for methanol synthesis.

ABOUT THE PROJECT


Project title: Circular Fuel Supply for Air Transport via Negative Emission Hydrothermal Liquefaction (CIRCULAIR)

PhD student: Carolin Eva Schuck

Project start: November 2023

Main supervisor: Patrick Biller

Co-supervisor: Konstantinos Anastasakis

Research section: Process and Materials Engineering


Model based prediction of methane emission from pig production facilities (PIGMET)

Livestock manure methane emissions account for roughly 20% of the agricultural sector's CO2 emissions. Current estimation methods, based on simple calculations involving volatile solids and temperature, work well for regional and average assessments but prove inadequate at the farm level due to variations in manure management and local conditions. Recent observations have highlighted significant emission differences even among seemingly similar pig farms, revealing gaps in our understanding of the factors affecting methane emissions. Microbiological activity and organic matter degradability are considered crucial, raising concerns about emission inventory accuracy. The Anaerobic Biodegradation Model (ABM) aims to predict farm-specific methane emissions by considering evolving methanogen populations and manure characteristics. However, the model's effectiveness relies on accurate input parameters, particularly the dynamic methanogen population and organic matter hydrolysis rates. Therefore, it is essential to measure these properties and establish correlations with methane emissions and farm management practices to refine ABM's algorithms and parameterization.

My task is: i): Methods for degradation measurement developed. ii): Degradation rates determined iii): Feed correlation analysis completed.

ABOUT THE PROJECT


Project title: Model based prediction of methane emission from pig production facilities (PIGMET)

PhD student: Rui Wang

Project start: October 2023

Main supervisor: Michael Jørgen Hansen

Co-supervisor: Frederik Rask Dalby

Research section: Environmental Engineering


MechanoGeometry

Recent research has revealed that cells are affected by their surroundings and structural changes around them. However, it is not completely understood how this plays out. This project intends to delve into the intricate interaction between cellular response and mechanical cues.

Utilizing Jens Vinge Nygaard's biomaterial, the project examines the impact of structural alterations on cell behavior. Mathematical models, acting as blueprints, are being developed to digitally represent these environments, aiding predictions of cell behavior through computational models. 3D and 2D images are used to create these blueprints. Techniques such as stereology, stochastic geometry, and biomechanics are integrated to identify the biomaterial traits. This approach not only seeks to validate existing theories but also push the boundaries of understanding how cells react to their mechanical surroundings, which is of high importance in stem cell engineering.

ABOUT THE PROJECT


Project title: MechanoGeometry

PhD student: Catalina Suarez Londoño

Project start: September 2023

Main supervisor: Jens Vinge Nygaard

Research section: Medical Biotechnology


Development of multispecific molecular engagers for protective immunization

This project focuses on understanding and interfering with the molecular events in immunological diseases. Several immune-mediated diseases are triggered or fueled by molecules which are recognized by the adaptive or innate immune system and thereby induce strong, potentially harmful responses.
The use of therapeutic antibodies has been a game changer in manifold diseases and has the potential to address future societal needs for healthy living. Molecular synergism might improve performance and broaden the scope of the concept.
In this interdisciplinary project, I will explore novel and unorthodox prevention and treatment strategies based on bi- and multi-specific molecular engagers that enable efficient trapping of target molecules and allow for inhibiting immediate immune reactions. In recent years, the concept of using single domain antibodies (nanobodies) as therapeutic building blocks has gained ground. Hence, I will develop and characterize novel nanobodies and use them for the design of advanced, multi-specific formats that have the capability for ultra-high blocking activity combined with enhanced effector functions compared to conventional antibodies. These formats might enable overcoming the risk of severe immune reactions in the individual patient.

ABOUT THE PROJECT


Project title: Development of multispecific molecular engagers for protective immunization

PhD student: Bjarke Krogstrup Jensen

Project start: September 2023

Main supervisor: Edzard Spillner

Research section: Medical Biotechnology


Dynamic modelling, optimization and transient analysis of green ammonia plant integrated with the latest generation of high-temperature pressurized solid oxide electrolysis cell (SOEC) reactor

Ammonia is an important chemical raw material and the main hydrogen energy carrier. It is synthetized by the reaction between H2 and N2. However, presently, most H2 used in ammonia production comes from fossil fuels through steam reforming, leading to a substantial carbon footprint. The electrolysis of water using the excess energy of renewable sources, such as wind or solar, has been known to be a promising route to produce “renewable” or “green” H2, and therefore, green ammonia. However, the fluctuations of the renewable power sources pose a significant intermittency and instability to the green ammonia production process. Studying the transient behavior of the process variables is essential to maintain a stable and safe operation. In this thesis, the dynamic modelling of the latest generation of high-temperature pressurized solid oxide electrolyzer cell (SOEC) reactor integrated with the dynamic simulation of the green ammonia process plant will be conducted. Firstly, a dynamic reactor model will be developed for the new emerging SOEC technology in Aspen Custom Modeler, as a standalone block, to account for the dynamics of electrochemistry, energy, and mass balance of the working fluids in the SOEC reactor. The SOEC reactor model will be verified against the experimental data. The verified SOEC reactor model will then be integrated into a dynamic ammonia production (Haber-Bosch) process model in Aspen Plus to study the detailed transient operation of the green ammonia process plant. Additionally, optimization will be conducted on the plant components capacity and configuration including H2 storage, batteries, thermal storage, air separation, and thermal integration of the exchangers network with high-temperature SOEC reactor with the aim of a more stable ammonia production. It is hopefully expected that the current research can put a step forward to a better understanding of the dynamic operation bottlenecks and basic design of the dynamic renewable-energy-powered ammonia process plant integrated with the developing SOEC technology and can significantly contribute to the systems level techno-economic analysis by giving clear insights on the process plant flexibility assumptions and estimations.

ABOUT THE PROJECT


Project title: Dynamic modelling, optimization and transient analysis of green ammonia plant integrated with the latest generation of high-temperature pressurized solid oxide electrolysis cell (SOEC) reactor

PhD student: Ahmad Golrokhsani

Project start: August 2023

Main supervisor: Anders Bentien

Co-supervisor: Behzad Partoon

Research section: Process and Materials Engineering


Hybrid Electrochemical System for Electricity & Hydrogen Storage

Project is related to research in a radically new energy conversion and storage concept that combines water electrolysis and battery storage into one single hybrid technology using soluble redox mediators as storage vectors. The ultimate goal of the project is to solve some of the fundamental challenges of the technology, make lab-scale proof-of-concept demonstration and pave the way for future upscaling/realisation of the technology. If successful the project is a potential game-changer within cost-efficient electricity storage and hydrogen production.

ABOUT THE PROJECT


Project title: Hybrid Electrochemical System for Electricity & Hydrogen Storage

PhD student: Albert Otto Erich Hohn

Project start: September 2022

Main supervisor: Anders Bentien

Research section: Process and Materials Engineering


Increased biogas formation from lignocellulosic compounds (BioMan)

My research focus is enhanced biogas production from lignocellulosic compounds in a methanogenic-aerobic-methanogenic (MAMB) switching system which poses a part of BioMan project titled Enhanced biogas production and antimicrobial removal from manure. It is claimed that the anaerobic-aerobic-anaerobic switch involving a shift from suspended methanogenic biomass to aerobic biofilm might be favorable for biogas production and will lead to increased biological hydrolysis of recalcitrant lignocellulosic material and make that available for biogas production.

During my project I will work to estimate an optimal operational parameters of biogas production e.g. reactor temperature, hydraulic residence time and aeration rate as well as lab digester type to create the most optimal conditions for enhanced biogas production. The appropriate combination of parameters will support aerobic transfer of cellulose and lignin as a recalcitrant material to short fatty acids (SCFA) for utilization for successive methane production in MAMB switching system. The best combination of the parameters will be selected and implicated into the project. Additionally, the gas composition in the aerobic steps will be investigated for nitrogen emission monitoring.

As a part of my project is an external stay and cooperation with Gent University in Belgium. During my stay, it is planned to work about advanced nitrogen management and ammonia stripping as well as to explore the processes in aerobic steps in terms of N2O production and impact on greenhouse gasses.

All these efforts will support the green transition by enhance regenerative economy by green energy production from wastes and reducing greenhouse gas emission to the atmosphere.

The project will be supervised by Senior Researcher Henrik Bjarne Møller and co-supervised by Professor Kai Bester.

ABOUT THE PROJECT


Project title: Increased biogas formation from lignocellulosic compounds (BioMan)

PhD student: Marcin Patryk Kozera

Project start: April 2022

Main supervisor: Henrik Bjarne Møller

Co-supervisor: Kai Bester

Research section: Environmental Engineering


Valorization of biogas to bio-methanol in Power-to-X schemes utilizing the eSMR technology

The novel electrically heated steam methane reformer (eSMR) technology offers a route to a practical zero-emission chemical plant with complete carbon utilization. This could be a key enabling factor for realizing sustainable chemicals production from biogas. Specifically, the technology offers a prospective feasible route for bio-methanol production where the synergy of CO2 and CH4 of the biogas feedstock is utilized in full. Recently, an early stage demo of the process has been obtained in pilot scale in an ongoing collaboration between Haldor Topsoe A/S, Department of Biological and Chemical Engineering - Aarhus University and others. However, many questions remain as to how the process can be applied optimally.

The goal of this project is to investigate the optimum operating condition for converting the biogas to methanol at pilot scale and increase the technology readiness level toward commercialization of such process. In this regard, the proposed objectives are as follow:
1) To demonstrate the role of carbon dioxide content of biogas on the synthesis gas production
2) To demonstrate the optimum operating condition to produce synthesis gas and green methanol from biogas
3) To model the eSMR process integration and simulate the power-to-methanol process in a steady state condition
4) To expand the utilization regime of biogas to chemicals through synthesis gas production.

ABOUT THE PROJECT


Project title: Valorization of biogas to bio-methanol in Power-to-X schemes utilizing the eSMR technology

PhD student: Thomas Norup From

Project start: March 2022

Main supervisor: Principal Scientist Peter Mølgaard Mortensen (Haldor Topsøe A/s) and Professor Anders Bentien 

Co-supervisor(s): Senior Process Engineer Marené Rautenbach (Haldor Topsøe A/S) and Assistant Professor Behzad Partsonn

Research section: Process and Materials Engineering  


Separation and recovery of inorganics during hydrothermal liquefaction of wastes

The current linear economic model is facing difficulties in addressing the demand for resources of a growing population and latest technological developments. The increasing demand for nutrients such as phosphorous (P) is influenced by the uneven distribution and depletion of phosphate rock throughout the globe. Moreover, P losses due to agricultural run-off and incineration of recyclable P sources such as sewage sludge are one of researchers’ main concerns regarding nutrients circularity within the bioeconomy.

Hydrothermal liquefaction (HTL) is a thermochemical processing technology that has been receiving increased interest to produce sustainable biofuels from wet feedstocks. Therefore, sewage sludge, manure and food waste are suitable for this technology without major pretreatment (i.e. drying). The process occurs at high temperatures and pressures in an aqueous environment.

These feedstocks have already been used to produce biocrude, however, they are typically high in inorganic content, remarkably in P, which may lead to complications during biofuel upgrading.

Therefore, future technologies that can utilize wet waste efficiently while also recovering valuable inorganic elements such as P, which is in high demand, are of major interest.

The current PhD aims to test the fractionation and speciation of inorganic elements into the HTL products derived from waste biomass in a continuous process. Moreover, testing different in line-separation mechanisms targeting the recovery of P to the solid product will facilitate its reincorporation within the circular economy.

ABOUT THE PROJECT


Project title: Separation and recovery of inorganics during hydrothermal liquefaction of wastes

PhD student: Maria Jose Rivas Arrieta

Project start: December 2021

Main supervisor: Patrick Biller

Research section: Process and Materials Engineering  


Development of new Biomaterials using Extracellular Polymeric Substances from Wastewater treatment

Biofilms are an untapped source of biological material value and could prove vital in the development of a more circular economy. Millions of tons of Wastewater treatment biofilms are produced and then destroyed every year in costly processes. This project aims to valorize these biofilms by isolating Extracellular Polymeric Substances (EPS) from them and use these for the development of new biomaterials. The objective is to investigate the composition of EPS as it has not yet been clearly defined in literature to comprehend its structure and properties by using novel solvents such as ionic liquids in analytical techniques.

Using techniques such as electrospinning and chemical reactions such as transesterification the aim of this project is to use EPS and take advantage of their emergent properties to develop fibers and bioplastics.

ABOUT THE PROJECT


Project title: Development of new Biomaterials using Extracellular Polymeric Substances from Wastewater treatment

PhD student: Javier Romero Gil             

Project start: November 2021

Main supervisor: Thomas William Seviour

Research section: Environmental Technology Engineering


Strategies and technologies for the characterization and mitigation of chemical air pollution in indoor environments

Indoor Air Quality (IAQ) has recently gained more attention as it has been recognized that citizens in developed countries spend approximately 90% of their time indoors. Thus the IAQ is an essential determinant of a healthy life and general well-being, especially due to increasing evidence linking adverse health effects, reduced learning, loss of productivity and general discomfort with exposure to indoor air pollutants.

This project therefore aims to provide a deeper understanding of the composition, sources and dynamics of indoor air pollution in indoor environments as well as to identify and develop the best strategies and technologies for detection and mitigation of hazardous indoor air pollution.

The project will have an increased focus on the indoor environments occupied by the youngest members of society (e.g. classrooms and day care facilities) as they have been proven to be especially susceptible towards low-quality air.

ABOUT THE PROJECT


Project title: Strategies and technologies for the characterization and mitigation of chemical air pollution in indoor environments

PhD student: Sara Bjerre Sørensen

Project start: November 2021

Main supervisor: Anders Feilberg

Co-supervisor(s): Kasper Vita Kristensen       

Research section: Environmental Engineering


Chemical-free Production of Superoxide Radical for Degradation of Persistent Organic Pollutants

Persistent organic pollutants (POPs) from wastewater are threatening human beings and receiving increasing attention all around the world. Per- and polyfluoroalkyl substances (PFAS) and florfenicol are two typical POPs with strong resistance to conventional water treatment technologies. Superoxide radical (O2•‒) is a sort of nucleophile with immense chemical and environmental importance in POPs control.

This study will construct two kinds of O2•‒ generating systems, i.e., photocatalytic system and electrochemical system. For the photocatalytic system, Bi2MoO6/g-C3N4 nanocomposites will be synthesized for the oriented transfer of photogenerated electrons and holes to pursue high yield of O2•‒. The physical and chemical properties of these photocatalysts will be studied by various characterization methods. For the electrochemical system, we will carry out a systematic study on O2•‒ generated in electrochemical flow loop, where the key parameters will be optimized according to the formation of O2•‒. Further, we will use the two systems to mineralize three short-chain PFAS and florfenicol. The presence of O2•‒ will be investigated using electron spin resonance, and the quantities of O2•‒ will be determined by colorimetric method. The entire reaction pathways for POPs degradation by O2•‒ will be mapped.

It is expected that the study could shed new light on the elimination of POPs induced by O2•‒.

ABOUT THE PROJECT


Project title: Chemical-free Production of Superoxide Radical for Degradation of Persistent Organic Pollutants

PhD student: Lu Bai

Project start: September 2021

Main supervisor: Zongsu Wei

Co-supervisor(s): Zheng Guo


Universal Organic redox active material for stationary batteries – UNIBAT

Renewable electricity sources are fully competitive to fossil-based ones and the major
challenge in completing the green transition is now energy storage. This includes batteries for stationary storage, where the estimated worldwide total installed capacity will increase from almost zero in 2019 to 100-450 GWh by 2030. Due to relatively high cost and environmental issues of state-of-the-art lithium ion (Li-ion) batteries there is a clear incentive to develop new environmental benign, low cost and long lifetime batteries.

This project will investigate the synthesis of quinone monomers having redox active properties. The synthesis will be carried out in a flow process and gradually strive towards automatic processing and later potentially autonomous synthesis. Subsequently, polymerisation of the quinone monomer will be performed, and a full characterisation will be conducted. Lastly, the quinone monomer and polymer will be applied in a battery test where the electrochemical and redox active properties will be characterised.

The overall goals of the UNIBAT project are to make significant advances within the research of novel aqueous batteries for stationary based on environmentally benign and low-cost materials and develop the foundation that enables upscaling of these post-project.

ABOUT THE PROJECT


Project title: Universal Organic redox active material for stationary batteries – UNIBAT

PhD student: Rune Kjærgaard Groven

Project start: September 2021

Main supervisor: Anders Bentien

Co-supervisor(s): Mogens Hinge, Emil Drazevic, Martin Lahn Henriksen


(A new twist on electrochemical ammonia synthesis) Novel Routes and Catalysts for Synthesis of Ammonia as Alternative Renewable Fuel (ORACLE)

The majority of renewable energy comes in the form of (intermittent) electricity. One of the ways of storing the renewable energy is in the form of green NH3. The PhD project aims to develop a technology for a decentralized synthesis of renewable ammonia, through a rational electrocatalyst synthesis and choice and design of local environment of the electrocatalyst.

In this project we will work on the development of an electrochemical process that could perhaps compete with conventional Haber-Bosch process at smaller scales.

The envisioned use can be storing electrical energy in ammonia and decentralized production of fertilizer feedstock.

The use of green NH3 fuel and zero carbon sources in synthesis processes is expected to play an important role in meeting national and international carbon reduction targets leading towards a zero-carbon future, including the 2015 Paris Agreement on Climate Change and the European Commission's Energy Roadmap 2050.

ABOUT THE PROJECT


Project title: (A new twist on electrochemical ammonia synthesis) Novel Routes and Catalysts for Synthesis of Ammonia as Alternative Renewable Fuel (ORACLE)

PhD student: Fateme Rezaie

Project start: June 2021

Main supervisor: Emil Drazevic


A new twist on ammonia production: more efficient electrochemical synthesis using “designer” hydrogen-binding mediators

Today’s ammonia production consumes approximately 1.2% of the world’s energy supply. The climate benefit of a green production path is therefore immense. Ammonia is simultaneously showing promising results as a Power-to-X product with an energy density 70% higher than hydrogen.

It is believed that electrochemical synthesis of ammonia can prove a green alternative to the Haber-Bosch process, especially in smaller production plants. The electrochemical synthesis is well studies in theory but struggles to transfer into experimental results. This project aims to aid that transformation by looking into materials and the synthesis of electrodes and electrolytes.

ABOUT THE PROJECT


Project title: A new twist on ammonia production: more efficient electrochemical synthesis using “designer” hydrogen-binding mediators

PhD student: Søren Læsaa

Project start: June 2021

Main supervisor: Anders Bentien

Co-supervisor(s): Emil Drazevic


Long term chemical stability of Vanadium Flow Batteries (Industrial PhD in collaboration with VisBlue)

The project is focused on increasing the fundamental understanding of long term (> years) chemical stability of liquid vanadium solutions in flow batteries. Because of the usage of the same solution in both half cells, vanadium cross-over in the stack has no damaging effect and Vanadium Flow Batteries (VFBs) are considered to have infinite lifetime. However, in practice there are three reversible mechanisms that can degrade the chemical integrity of VFBs and lead to capacity loss over time: (1) external oxidation, (2) vanadium/volumetric crossover and (3) temperature stability.

Through lab-scale proof-of concept, the goal is to quantify these mechanisms and develop new methods that would reverse the degradation. Additionally, in co-operation with VisBlue, the aim is to implement these methods in real battery systems.

ABOUT THE PROJECT


Project title: Long term chemical stability of Vanadium Flow Batteries (Industrial PhD in collaboration with VisBlue)

PhD student: Sara Noriega Oreiro

Project start: April 2021

Main supervisor: Anders Bentien

Co-supervisor(s): Marta Boaventura, Morten Brun Madsen, Søren Børen.


Profiling the degradation and toxicity of short-chain per- and polyfluoroalkyl substances (PFAS) in water

Per- and polyfluoroalkyl substances (PFAS) are a class of man-made chemicals that have unique properties, such as amphiphilic nature, and thermodynamic, physical and biological stability. PFAS are detected in the environment globally and have adverse effects on human’s health. Since 2002, PFAS manufacturers started to replace long-chain PFAS with unregulated short-chain PFAS (typically with carbon number less than 7), which were consequently widely used but not fully investigated. Short-chain PFAS are already found in the environment (concentrations range from ng/L to µg/L). They are less adsorbable, are transported over longer distances in the environment and may persist longer in the environment and organisms. They may also have more serious adverse health effects, but this aspect has not been fully investigated yet. Our knowledge to efficiently remove short-chain PFAS contamination from wastewater to prevent adverse effects in humans and the environment still remains limited.

This project aims to investigate and enhance the potential of photo-catalysis to degrade short-chain PFAS by defluorination. Quantitate and qualitative analysis will be performed by ultra-high performance liquid chromatography - high resolution mass spectrometry. In vitro bioassays will be used to investigate the removal of toxicity caused by PFAS and their transformation products.    

ABOUT THE PROJECT


Project title: Profiling the degradation and toxicity of short-chain per- and polyfluoroalkyl substances (PFAS) in water 

PhD student: Junying Wen 

Project start: October 2020

Main supervisor: Lars Ottosen

Co-supervisor(s): Leendert Vergeynst & Zongsu Wei


Novel Dual-reaction Centre Fenton-like Catalysts for Effective Degradation of Persistent Organic Pollutants (POPs)

The worldwide release of persistent organic organic pollutants (POPs) has caused serious pollution to the water environment and thus endangered human and ecosystem health. To address this challenge, advanced oxidation processes (AOPs) have become a research hotspot in the field of water purification. Among them, Fenton catalytic oxidation can produce hydroxyl radicals (•OH) that will destroy the structure of organic pollutants without selectivity. However, most of the polyphase Fenton catalysts developed at present are doomed to have low activity, poor stability  and low utilization of oxidants under neutral conditions. Dual-reaction center is a new mechanism of Fenton-like process to avoid problems mentioned above by separating the oxidation and reduction sites.  In this project, we plan to prepare novel Fenton-like catalysts with dual-reaction center and combine with interfacial reaction to degrade POPs rapidly under ultra-low concentration of oxidants. Further, we hope to improve the degradation of pollutants under neural conditions by in-situ production of hydrogen peroxide on the surface of catalysts without adding oxidants.    

ABOUT THE PROJECT


Project title: Novel Dual-reaction Centre Fenton-like Catalysts for Effective Degradation of Persistent Organic Pollutants (POPs) 

PhD student: Zhiqun Xie 

Project start: October 2020

Main supervisor: Zongsu Wei


Novel adsorptive composite materials for catalytic ozonation of micropollutants in water

The instability and low solubility of ozone (O3) molecule in liquid phase limit the effective contact between micropollutants and O3/hydroxyl radicals (OH) in water. Thus, the uncompleted utilization of ozone molecule is largely prevalent in O3-based advanced oxidation processes (AOPs). This project hopes to promote O3 utilization by extending the O3 retention time in the liquid phase and enhancing the contact between micropollutants and oxidants. In particular, we will synthesize a uniquely hydrophobic adsorbent with pine-needle-like hierarchical nanostructures that can simultaneously capture O3 molecules and micropollutants. We will later load a catalyst on the surface of pre-prepared adsorbent to realize the efficient oxidative degradation of micropollutants on the surface of this composite. To investigate the performance of the prepared material, we will select herbicide glyphosate (Gly, N-(phosphonomethyl) glycine) as a model micropollutant and study the degradation pathway.    

ABOUT THE PROJECT


Project title: Novel adsorptive composite materials for catalytic ozonation of micropollutants in water

PhD student: Xingaoyuan Xiong 

Project start: October 2020

Main supervisor: Zongsu Wei 

Co-supervisor(s): Alberto Scoma 


Exploring natural and artificial biofilms of acetogenic bacteria to improve microbial electrosynthesis rate

Microbial electrosynthesis is a novel biotechnological process for the conversion of electricity and CO2 into biofuels or other organic compounds. Microbial electrosynthesis could in the future contribute to the desired lowering of CO2 emissions, while at the same time storing excess renewable energy and producing sustainable biochemicals.

Microbial electrosynthesis is carried out by acetogenic bacteria (e.g. Sporomusa ovata), which are capable of reducing CO2 to organic compounds, using an electrode as the electron donor. One of the major obstacles that limits the rate of microbial electrosynthesis, and hence its upscaling beyond lab-scale, is the low number of cells that attach to the electrode. Currently, very little is known about attachment and biofilm formation by S. ovata. The goal of this project is to increase the cell numbers of S. ovata on the electrode, using two different strategies. First, natural biofilm formation will be stimulated and investigated. Second, artificial biofilms will be created by immobilizing cells in polymeric matrices. The different types of biofilm will be characterized using state-of-the art techniques (microsensors, confocal microscopy, etc.) and the effect of increased cell numbers on the electrode on microbial electrosynthesis rates will be investigated. 

ABOUT THE PROJECT


Project title:  Exploring natural and artificial biofilms of acetogenic bacteria to improve microbial electrosynthesis rates     

PhD student: Louise Vinther Grøn 

Contact: louise.groen@eng.au.dk

Project start: May 2020

Main supervisor: Assistant Professor Jo Philips 

Co-­‐supervisor(s): Assistant Professor Klaus Koren and Associate Professor Alberto Scoma