Sequestration of metals from legacy ponds using artificial corals

In the 1970&rsquo;s work was started to grow artificial corals in order to remediate damage to natural systems. The method was to use an electrochemical process to deposit a hard ceramic material from the metals and anions present in sea water and this created what was essentially brucite (Mg(OH)2) deposits on a cathode. The work was reported as electrochemical deposition; which equates to electrowinning, as the anode was sacrificial, consisting of steel meshes.<br /> <br /> More recently, a PhD project at Leeds has proven that metallic magnesium (as a cathode) can be directly converted in to a cementitious phase (brucite + hydromagnesite) in high salt concentrations. The cement formed is stable and would be suitable as a waste form.<br /> <br /> At Sellafield there are legacy facilities that contain sludges and metallic scrap that has slowly dissolved into the surrounding water. Whilst Sellafield Ltd has been developing technologies to deal with the sludges and metallic scrap, the water itself remains an issue, as it contains high level of magnesium, fission product metals and hydroxide ions.<br /> <br /> The aim of this project is to investigate the electrochemical deposition of magnesium and fission product metals in the presence of hydroxide and carbonate ions in order to determine whether electrowinning or electromigration dominate and define conditions under which a ceramic phase can be produced. <br />

<p style="margin-bottom:11px">The project will rely on an accurate simulation of the systems that are present at Sellafield. Therefore the first stage will be to work with the industry supervisors to build up a chemical map of the legacy ponds and silos. In conjunction, with a generic review of aqueous magnesium chemistry, specifically on hydroxide and carbonate systems, this will create the chemical foundation of the project. Once this stage is complete, a series of simulant liquors will be formulated (using techiques such as ICP-MS to determine accurate chemical analysis). Electrochemical analysis, such as voltammetry, will be then be used to determine the envelop of operation for electrodeposition; i.e. maximum potentials and mapping of redox processes vs. potential.</p> <p>Once the initial phase is complete and a simulant liquors are established, then a series of investigation will commence on electrodeposition. This investigation will be done using controlled conditions with single point (wire) electrodes of known and controllable surface area, with reference electrodes. The main objective will be to determine deposition rates vs. chemical conditions and establish the proof of concept for brucite deposition.</p> <p>Once initial investigations are complete with a simple electrode system, then the process will be scaled up to (litre) investigate electrodes will high surface area and deposition capacity, for example mesh sheets and baskets. Again, the main objective will be to determine deposition rates vs. chemical conditions and establish the proof of concept for brucite deposition, but also to determine deposition capacity.</p> <p>The above will be carried out with magnesium and hydroxide only and once complete, then the full-simulated legacy liquors will be investigated to determine the extent of incorporation into the deposit of dissolved fission products.</p> <p>Information from the experimental investigations will be used to construct a process model (using gProms) of the system, so that the efficacy can be determined.</p> <p>A final stage will be to investigate the physical and chemical durability of the deposition. A standard range of microscopy, with EDX analysis and hardness testing will be used. Also, depending the physical nature of the deposition and whether an accurate measurement of surface area can be determined, a leach test (e.g. MCC-1) will be carried out.</p> <p>&nbsp;</p>

<p>Formal applications for research degree study should be made online through the&nbsp;<a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University&#39;s website</a>. Please state clearly in the Planned Course of Study section that you are applying for <em><strong>EPSRC Nuclear Energy-GREEN</strong></em> and in the research information section&nbsp;that the research degree you wish to be considered for is <em><strong>Sequestration of metals from legacy ponds using artificial corals</strong></em>&nbsp;as well as&nbsp;<a href="https://eps.leeds.ac.uk/chemical-engineering/staff/522/professor-bruce-hanson">Professor Bruce Hanson</a>&nbsp;as your proposed supervisor.</p> <p>If English is not your first language, you must provide evidence that you meet the University&#39;s minimum English language requirements (below).</p> <p><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p> <p class="MsoNoSpacing">Applications will be considered on an ongoing basis. &nbsp;Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application. &nbsp;We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed.</p> <p>Please note that you must provide the following documents in support of your application by the closing date of 28 April 2023:</p> <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date</li> <li>Personal Statement outlining your interest in the project</li> <li>CV</li> <li>Funding information:&nbsp; EPSRC CDT Nuclear Energy - GREEN</li> </ul>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<p>A highly competitive <a href="https://www.nuclear-energy-cdt.manchester.ac.uk">EPSRC Centre for Doctoral Training for GREEN</a> studentship consisting of the award of fees with a maintenance grant (currently &pound;17,668 in session 2022/23) for 4&nbsp;years.<br /> <br /> This opportunity is open to UK applicants only. All candidates will be placed into the EPSRC Centre for Doctoral Training for GREEN Studentship Competition and selection is based on academic merit.<br /> <br /> Please refer to the&nbsp;<a href="https://www.ukcisa.org.uk/">UKCISA</a>&nbsp;website for&nbsp;information regarding Fee Status for Non-UK Nationals.</p>

<p>For further information about your application, please contact Doctoral College Admissions<br /> e:&nbsp;<a href="mailto:phd@engineering.leeds.ac.uk">phd@engineering.leeds.ac.uk</a></p> <p>For further information about this project, please contact Professor Bruce Hanson<br /> e:&nbsp;<a href="mailto:b.c.hanson@leeds.ac.uk">b.c.hanson@leeds.ac.uk</a></p>