Assessing the sustainability of iron clay mineral redox reactions for application in engineered systems

Lead Research Organisation: Newcastle University
Department Name: Sch of Engineering

Abstract

The quality of surface and groundwater is strongly influenced by redox reactions of iron-bearing minerals, which transform contaminants and nutrients. Iron-bearing clay minerals are particularly important because they are thought to be a renewable source of reduction equivalents in the environment. In this project, we will test the validity of this paradigm and expand current knowledge from closed systems to more realistic, flow-through conditions. Specifically, we will investigate aspects of reversibility of clay mineral redox reactions; the effect of redox cycling on clay mineral stability and reactivity; and differences between chemical, microbial, and biologically mediated clay mineral iron reduction. We will complement our experimental work with quantitative modeling of the processes involved. The results of this project will aid in designing effective (natural) remediation strategies as well as engineered water systems such as aquifer storage and recovery.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509528/1 01/10/2016 31/03/2022
1948826 Studentship EP/N509528/1 01/10/2017 31/03/2021 Harry James Brooksbank
 
Description Our results so far show that the reactivity of the clay minerals is insignificantly impacted by redox cycling with dithionite, whereas cycling with aqueous Fe(II) causes a significant increase in reactivity towards the degradation of model contaminant 3-chloronitrobenzene. The latter is more environmentally relevant due to the natural abundance of aqueous Fe, and is likely due to the formation of new Fe precipitates on the mineral surface. We also now know that NAu1 clay mineral can be reduced with AQDS electron shuttling compound, however this has little effect on the structure or reactivity. Mineral precipitates formed by reduction with aqueous Fe(II) leads to lepidocrocite and some goethite when oxidised, we are continuing to characterise the reduced form of these minerals with Mossbauer and XRD. We do not see any evidence for dissolution of Fe out of the mineral structure, as has been suggested by some researchers, and this indicates the Fe-bearing clay minerals could act as renewable and sustainable materials for environmental remediation. Mossbauer results seems to suggest that as we cycle the mineral, structural Fe seems to change from being held in an ordered form into less ordered species of Fe, however this effect is also reversed when the sample is left for a long period of time. This all suggests that redox cycling does impact the structure, however the effects do not leave long-lasting impacts on the reactivity or structural resilience meaning clay minerals could be used as sustainable and renewable resources for engineering purposes.
Exploitation Route If clay minerals are (as results might suggest) renewable materials for redox reactions, this will make them of interest to multiple industries. Proving that the minerals are resilient over time to fluctuating redox conditions means they are useful from many industrial perspectives as engineering components.
Clay minerals are used a wide variety of applications, and their resilience and utility with regards redox reactions might be useful in fields such as environmental engineering, radioactive waste disposal, pharmaceuticals, construction, paints / coatings, and many more.
How these minerals change over cycles of reduction-oxidation and especially their resistance to dissolution affects many valuable industries, as well as being integral to natural environments and systems.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Construction,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

 
Description Action For Impact 3 day residential 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Completed a 3-day residential workshop at Slaley Hall Northumberland, on how to increase research impact and how to boost the entrepreneurial side of scientific research. Involved various seminars, talks, and enabled me to speak to people from various backgrounds about my research.
Year(s) Of Engagement Activity 2019
 
Description Euroclay 2020, International Clay Mineral conference, 1-week in Paris - included poster presentation to many clay mineral experts. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Attended 1-week Euroclay Conference 2019 in Paris, gave a poster presentation on my current results at a conference of hundreds of experts from academia and industry. Received a lot of attention and answered a lot of questions from interested academics from various different fields and countries. Poster was generally well received.
Year(s) Of Engagement Activity 2019
URL https://euroclay2019.sciencesconf.org/
 
Description Lightning talk and poster presentation at H7O Water Symposium 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other audiences
Results and Impact Gave a short lightning talk, as well as presented my research results to various professionals and academics within the water sector, under the sub-group of environmental contaminant treatment.
Imporved impact to members of industry, and research who might be interested with our research for use in water treatment, and made a number of useful contacts who we may collaborate with later.
Year(s) Of Engagement Activity 2020
 
Description Oral presentation at Clay Minerals Society - Research in Progress meeting 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other audiences
Results and Impact Presented the latest results of my research to the Clay Minerals Society : Research in Progress meeting in Newcastle 2019.
Audience members included experts from both academia and industry.
Engaged in discussion and answered many questions for audience members.
Won runner-up award for Best Presentation
Year(s) Of Engagement Activity 2019
 
Description Oral presentation at Clay Minerals Society Conference 2020 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presented latest research findings virtually at the Clay Minerals Society Conference 2020 - originally planned to take place at PNNL Washington State
Year(s) Of Engagement Activity 2020
 
Description Poster presentation given at Clay Minerals Society : Research in Progress meeting 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other audiences
Results and Impact Presented a preliminary research poster to the Clay Minerals Society : Research in Progress meeting in Sheffield 2019

Audience members from industry and academia.
Answered questions and engaged in discussion with various delegates.
Awards Runner-up for Best poster award.
Year(s) Of Engagement Activity 2018