PhD cohort 2
In 2020, the Transition to Zero Pollution initiative formed a second cohort of 12 students from across College carrying out research related to TZP. The students are all aligned with the NERC-funded Science and Solutions for a Changing Planet DTP run by the Grantham Institute. Find out more about the students' projects below.
Emma Beirns - Co-metabolism of sulfonamides in anaerobic wastewater treatment incorporating direct interspecies electron transfer
Department of Civil and Environmental Engineering
Supervisor: Dr Po-Heng (Henry) Lee
Funder: Department of Civil and Environmental Engineering and UKRI EPSRC
Anaerobic wastewater treatment technologies are already contributing to global sustainability efforts: clean effluent can be used as irrigation water; nutrient-rich sludge can be used as fertiliser; and methane-rich biogas can be used to generate electricity. The recovery of these resources facilitates the transition to zero pollution by curtailing demand for intensive raw production processes. However, the safety of utilising effluent and sludge from biological wastewater treatment plants is being scrutinised due to the presence of antibiotic residues and associated resistance genes. Research has shown that biological wastewater treatment, including anaerobic treatment, can remove >95% of antibiotics, although the mechanisms are not fully understood.
This research project is focused on observing the degradation of one class of antibiotics – sulfonamides – in a novel anaerobic fluidised-bed membrane bioreactor (AFMBR). This reactor type has demonstrated high effluent quality at retention times similar to conventional aerobic treatment, however, with the benefit of high pharmaceutical removal and sufficient biogas production to balance operational power demands. This is hypothesised to be due in part to direct interspecies electron transfer (DIET) via the granular activated carbon (GAC) media used in AFMBR. By focusing on sulfonamides and determining the associated degradation genes, an investigative method will be developed that may be applicable to other antibiotic classes, leading to further developments in pharmaceutical removal techniques. This will ultimately preserve the utility of the resources contained within wastewater and prevent a return to raw production processes.
Abigail Croker - Institutions, Governance and Policy for Addressing Wildfire Challenges in a Changing Global Environment
Centre for Environmental Policy
Supervisor: Dr Yiannis Kountouris
Funder: UKRI NERC (SSCP DTP)
This PhD will be examining the importance of social organization, institutional quality and socioeconomic variables in determining wildfire risk, occurrence, and impact across global ecosystems. The analysis will take place in the context of uncertainties introduced in wildfire management and fire regimes by anthropogenic environmental change; looking at developing effective and sustainable agricultural, forest, and fire management policies to improve resilience to wildfire while maintaining the benefits from natural resource use. A transition to zero pollution requires an understanding of the political ecology of wildfire complexities and uncertainties across all global ecosystems, whilst also considering their role in Earth’s climate system due to increasing greenhouse gas emissions.
Sam Hair - Nanoscale design of battery electrodes for improved performance and lifetime
Department of Materials
Supervisors: Professors Milo Shaffer, Mary Ryan and Magda Titirici
Funder: UKRI EPSRC iCASE Award
Industrial partner: Shell
To maintain grid stability, utility companies must ensure that supply of electricity is always matched with demand. Today, this constant balancing act is enabled by the ability of fossil fuels to be burnt on demand: if it isn’t very windy, gas is burnt at a faster rate.
As fossil fuels on the grid are replaced by renewable energy sources, more grid-scale energy storage will be essential to store excess electricity (generated on the windy days) and then release it at a time of need (when the wind stops). Batteries are one form of grid-scale energy storage.
The role of battery electrode structure has been poorly explored in the literature, but nanostructured electrodes in principle offer many advantages including faster charging and higher energy capacity. The goal of this project is to develop optimised anodes for sodium ion batteries that will improve performance and illustrate a design philosophy for other battery chemistries.
Sarah Kakadellis - Assessing the suitability of biodegradable bioplastics in food waste anaerobic co-digestion within the Bioeconomy
Centre for Environmental Policy
Supervisors: Dr Zoe Harris, Dr Jem Woods and Dr Po-Heng (Henry) Lee
Funder: UKRI ESRC (LISS DTP)
The use of plastics is a contentious issue at the heart of our throwaway society. The recent years have placed plastic pollution under growing public scrutiny, favouring the development of ‘greener’ plant-based plastic materials. However, such bio-based biodegradable alternatives may not necessarily provide an improvement in overall environmental impact and little is known about their end-of-life management. Adopting an interdisciplinary perspective, this research project explores bioplastics waste management and aims to assess the suitability of biodegradable plastics in the current food waste anaerobic digestion infrastructure and their potential to optimise biogas production from food waste management. To achieve this, chemical and genetic analyses will be performed to characterise the bioplastic-food waste anaerobic system at a macro and micro level, with a further goal to identify genes (and biochemical pathways) associated with bioplastic degradation. The PhD also incorporates social sciences, through semi-structured interviews. Understanding barriers from real-world cases and identifying mismatches in academic research, current waste management infrastructure and the policy landscape will help building a more comprehensive framework for biodegradable plastics within the bioeconomy.
Maria Koulouri - Resource Recovery from Faecal Sludge
Department of Civil and Environmental Engineering
Supervisors: Professor Michael Templeton and Dr Geoff Fowler
Funder: Department of Civil and Environmental Engineering Skempton Scholarship
The United Nations (UN) Sustainable Development Goal 6 (SDG 6) aims to ensure availability and sustainable management of water and sanitation for all by 2030. However, 4.2 billion people worldwide still do not have access to safely managed sanitation services. Approximately 3.1 billion people rely on pit latrines and other improved on-site sanitation facilities.Excreta from such facilities, known as faecal sludge, can have detrimental environmental impacts if they are not safely managed.
This project focuses on the assessment of novel treatment technologies, such as pyrolysis, in order to develop a holistic faecal sludge management approach that provides wider environmental benefits through resource and energy recovery. Resource recovery opportunities from faecal sludge pyrolysis include the production of a nutrient-rich biochar that can be used in agriculture, as a soil amendment. At the same time, the biochar is a carbon-rich material and its efficient application offers carbon sequestration benefits. Sludge derived fuels can be used as a greener alternative to fossil fuels, also contributing to climate change mitigation.
Priyanka Kumar - Building a spent grain biorefinery based with low-cost ionic liquids
Department of Chemical Engineering
Supervisors: Professor Jason Hallett and Dr Agi Brandt-Talbot
Funder: Department of Chemical Engineering
Spent grain, a biomass residue from brewing, is a major industrial biomass by-product in the UK and worldwide. This project focuses on the application of low-cost ionic liquids to the processing of Brewer’s Spent Grain (BSG), to produce biomaterials and value-added products, including proteins. The ionoSolv process will be used to fractionate BSG into cellulose, lignin and protein. IonoSolv pretreatment of biomass is a patented new biomass fractionation process developed at Imperial College (commercialisation by Lixea LTD, www.lixea.co) but has not been optimised for protein-rich lignocellulose such as spent grain. In this project the extraction, recovery and purity of the proteins from spent grain will be optimised, while maximising the quality of the other fractions. Biomaterial and bio-based chemical product options such as lignin carbon fibres and nanocellulose will also be evaluated. Ultimately the aim is to develop greener alternatives to today’s petrochemical industry, while providing unwanted waste materials with a new purpose. For example, creating carbon fibres from lignin has the potential to sever fossil fuel dependency of carbon fibre production, reduce the environmental impact of the process and drastically cut its cost by more than 75%.
Anthony Onwuli - Rapid computational screening of materials for energy storage
Department of Materials
Supervisor: Professor Aron Walsh
Funder: UKRI EPSRC DTP
This PhD project will use materials informatics - a combination of computer science and materials science - to develop software for the rapid screening and identification of new chemical spaces for energy storage. The project will be focused on the substitution of existing components that are formed of non-toxic or rare elements, e.g. LiCoO2 cathodes in high-density Li-ion batteries. Critical to this will be metrics relating to materials sustainability, including element abundance, production rates, as well as geopolitical factors. The research will combine elements of first-principles simulations (density functional theory) together with chemical filters developed through statistical analysis (machine learning) of structure and property datasets.
Geraldine Regnier - Numerical modelling of low-enthalpy geothermal reservoirs
Department of Earth Science and Engineering
Supervisors: Professor Matthew Jackson and Dr Pablo Salinas
Funder: UKRI EPSRC
Geothermal energy production has been growing globally in the past decades, providing a low-carbon and equitable baseload energy source. Subsurface aquifers can provide geothermal energy and also be used to store thermal energy, by pumping hot water in to the aquifer and stored to provide heating in winter. This provides an opportunity to decarbonise heating, which is today mostly satisfied by fossil fuels.
In order to de-risk, develop and manage geothermal and aquifer thermal energy storage projects, it is essential to use numerical models to predict fluid flow and heat transport in reservoirs. This project will apply the Imperial College Finite Element Simulator (IC-FERST), a next-generation adaptive-mesh simulator, to low-enthalpy geothermal sedimentary reservoirs. The first aim will be to demonstrate the numerical capabilities of the simulator, particularly the benefits of adaptive meshing. The project will then focus on applying the code to a range of case studies, investigating the effects of subsurface heterogeneity, how neighbouring installations interact and how energy production can be optimised.
Felix Richter - SPORES-ON-A-CHIP: Investigations on arbuscular mycorrhizal fungi using novel microfluidic technology
Department of Bioengineering
Supervisors: Dr Claire Stanley and Professor Darryl Overby
Funder: Department of Bioengineering
Arbuscular mycorrhizal fungi (AMF) form one of the most important classes of soil fungi, colonising roots of more than 80% of all plant species on Earth. They also contribute to carbon storage, the regulation of greenhouse gas emissions as well as bioremediation. AMF also have the potential to reduce the need for fertilisers and pesticides, increasing the sustainability and environmental impacts of agriculture. This project aims to develop a novel microfluidic device to gain experimental access to spores of AMF at the cellular level in real time. The major goal is to investigate how physical obstacles induce a physiological response in AMF hyphae. Preliminary data revealed that pre-symbiotic arbuscular mycorrhizal fungal hyphae branched extensively after colliding with physical obstacles. This stimulation of high-density hyphal branching suggests that AMF may be able to exploit such mechanisms for survival by increasing the chance of finding and/or penetrating a plant root and represents the first observation of its kind for AMF.