Overview

Project Highlights:

  • Use a variety of novel techniques, state-of-the-art equipment and experiments to explore how plastics behave as sedimentary particles
  • Acquire a suite of analytical skills for chemical and physical characterization and statistical skills for robust analyses of data
  • Investigate an emerging and novel field working with a team at the vanguard of Anthropocene research in the earth science context

Overview

This project will use a suite of cutting edge analytical techniques and experimental design to address an important and significant problem: the behaviour of plastics within the geological cycle. A number of recent studies have elucidated the extent of the plastics problem on Earth with now 8.3 billion tons on our planet (Geyer et al. 2017), much of which (between approximately 5-nearly 13 million tons per year) ends up in the ocean (Jambeck et al 2015). Plastic is a major environmental problem and research issue which has emerged over the last decade:  the scale of the problem is huge and getting bigger. To date, focus has been on the biological interactions of this material, but there are significant gaps in our knowledge especially in the area of how plastic behaves as a component of the geological cycle. We do not know how plastics behave as ‘sedimentary’ particles, both macro and micro on land and in rivers, lakes and the sea, how they get deposited and their short and long term fate once deposited and buried. This research will find out through combing laboratory experiments with fieldwork collecting data on plastics. Laboratory experiments will be a significant focus of the project, and will be designed to model a suite of processes that have the potential to affect how plastic is transported and chemically and physically modified from its journey from land, through to seafloor and beyond. We will focus on just a few of the environmental compartments in which plastic is found. The project involves a high level of problem solving, in that designing suitable experiments to model environmental processes will be a key component followed by testing the applicability of models to plastic collected from the environment. Established protocols for such data collection are not available so the student will be at the vanguard of designing and testing models and their applicability.

Methodology

The project has two principal strands: one is laboratory based, the other requires fieldwork and collection of plastics; both aspects will require the student to use state-of-the-art chemical analytical equipment to characterize plastics, including Gas Chromatography–Mass Spectrometry (GC-MS) and FTiR, and imaging techniques including scanning electron microscopy and Initinte Focal Microscopy. In the laboratory, robust experimental design will be used to test hypotheses. Alongside laboratory work there will be opportunities for fieldwork in several environments including rubbish dumps, shorelines and the ocean; some snorkelling/scuba diving (note scuba qualification is not a pre-requisite as most can be collected through snorkelling) may be required to collect plastics. Anticipated fieldwork areas are in either Kenya or Malawi and Egypt or Israel, as well as sites across the UK. Chemical analyses will employ a range of techniques most notably GCMS and textural analyses will use quantitative 3D analyses using methods developed at Leicester (Purnell et al. 2013). Experiments will use flume tank systems to model transport. Plastics in the field will be compared to those used in experiments to asses how closely experiments match real world plastic transformation.

Training and Skills

Core training will include: experimental design (including attending an undergraduate level Module on this if appropriate), use of GC-MS for molecular analysis, use of Infinite Focal Microscopy and Scanning Electron microscopy for imaging. The emphasis will be on laboratory experiments, robust quantitative analysis and statistical hypothesis testing, alongside comparison of experimental models with plastics collected from a variety of locations. As well as being trained how to write articles for peer-review, and present posters and conference talks the student will benefit from a supervisory team with a strong track record in engaging in public understanding of science from popular science books, broadcasting media and exhibitions.

Timeline

Year 1: basic research training; familiarization with literature, existing proof of concept datasets and training on chemical analytical techniques. Commence pilot experiments to evaluate efficacy and determine protocols and additional hypothesise to test. Organisation of collecting visits (Kenya and Egypt/Israel).

Year 2: Collection of plastics from different target locations. Analyses of these and set up of a suite of laboratory experiments to investigate a series of hypotheses relating to plastic behaviour/transformation. Image analyses of experimental and real world plastics.

Year 3: Statistical testing of results and analysis and modelling of the experimental runs to constrain the medium and long term fate of plastics as particles of the geological cycle. Writing papers for publication.

Partners and collaboration (including CASE)

Prof. Sarah Gabbott has developed a holistic research program that has focussed on how we read and interpret fossils through understanding the range of processes that effect how carcasses get in to the fossil record and what they end up being composed of. Dr Arnoud Boom is an organic geochemist and leader in use stable isotopes and mass spectrometry to characterise and interpret biomolecules. Profs. Jan Zalasiewicz and Mark Williams are both world renowned for their work on the Anthropocene and have published both popular science books and high impact journal articles on the subject. Prof Mark Purnell leads research on quantitative textural analysis of teeth and has developed new applications these techniques. 

 

Further Details

School of Geography, Geology and Environment, University of Leicester, Leicester LE1 7RH. Emails sg21@le.ac.uk (Gabbott); ab269@le.ac.uk (Boom); map2@le.ac.uk (Purnell); jaz1@le.ac.uk (Zalasiewicz); mri@le.ac.uk (Williams).