Overview

Project Highlights:

  • Investigate flow of microplastics in our environment
  • Assess impact of microplastics on soil nutrients
  • Work with leading UK water companies

The impact of plastics on our environment has gathered huge attention recently following the awareness raised by the BBC landmark series, Blue Planet II where the Open University was a partner. There is a growing public drive and commitment from all stakeholders to remove plastics from our environment through identification of the level of pollution, implementation of clean-up operations (such as beach cleaning) and reduction of usage. It is relatively easy to identify and clean up large and visible plastics present in our environment, but once these are broken down into smaller particles such as microplastics (MPs), it is extremely challenging to identify their presence, record their movement and clean them up. MPs have now been identified everywhere on Earth, yet we know little about their impact on our living environment.

The presence of MPs (<5 mm to 500m) in our natural water system is well known. However, the flow of MPs from the source to our environment through the water cycle, into the soil and its impact on soil nutrients are less well quantified. Additionally, a recent study of UK Water Industry Research showed that our water treatment plants are effectively removing MPs but revealed the presence of MPs in the wastewater and sludge treatment line1. One-way MPs are finding ways into the soil is land application of sewage sludge and from wastewater discharged into the water bodies2. This project will investigate: how MPs move from the wastewater and sludge into our living environment and its impact on soil nutrients, biota and plants. The sampling of water and sediments at the source to the exit point will be carried out to identify flow3 of MPs in the natural and wastewater systems, interaction of MPs on soil nutrients and impact on soil biota and plants.

Effects of microplastics in our environment [2].v

Methodology

To investigate flow of MPs in water systems, water samples will be filtered using 63 mm sieve to extract particles including MPs. The MPs from sediment and soil samples will be extracted using a density separation technique3&4. Approximately 10g of sediment subsample will be first wet sieved through a 63 mm sieve to separate the silt/clay and sand fractions as any smaller particles cannot be reliably identified as plastic material4. The sand fraction will then be oven dried at 50°C. All samples will be processed in triplicate to obtain a statistically significant estimate of MPs. The dried samples will be analysed under binocular microscope to identify distribution of MPs. Further, chemical identification of MPs will be carried out using the Fourier Transform Infrared (FTIR) technique at the Open University. Soil nutrient analysis will be carried out at the Ecosystem laboratories at the OU. Data will be assessed following statistical treatment. Open source trajectory modelling will be used, as necessary, to assess flow of MPs in natural system4.

Training and Skills

Student will be trained in sampling techniques, laboratory skills (PA, WF and YA), statistical (YA) and modelling (KHS) methods. Student will have an opportunity to work with Severn-Trent Water in sample collection and processing (PV). Student will acquire a wide range of skills through this project to get trained in skills for a potential to explore future employability in UK water company/Severn-Trent Water.  

Timeline

Year 1: Read literature, define sampling plan and collect water and sediment/soil sampling and sludge treatment line. Process samples for one study site and learn statistical treatment of data to carry out data analysis.

Year 2: Interpret data and write while continue with sample processing from other sites collected in year 1. Carry out year 2 sampling and process samples and data. Carry out flow of MPs modelling. Potential publications on methods and results.

Year 3: Finish analytical work, compile all data and carry out data analyses. Prepare manuscript and write remaining papers and/or Thesis chapters. Submit thesis.

Year 4: Revise manuscripts for final submission and submit thesis.

Partners and collaboration (including CASE)

The project offers extensive opportunities for the student to interact and collaborate with scientists involved in complementary research. This project benefits from project partners Severn Trent Water and Met Office and access to sampling and modelling techniques.

Further Details

Students should have a strong background in environmental science, soil or biogeochemical sciences. Experience of laboratory analysis and a strong interest in topical environmental issues are highly desirable. The successful student will join a well-established interdisciplinary team researching ecosystem processes utilizing diverse set of chemical and physical analysis methods. The school ‘s substantial number of students make up part of the vibrant postgraduate community at the Open University.

Please contact Dr Yoseph Araya, Yoseph.Araya@open.ac.uk or Dr Pallavi Anand, Pallavi.Anand@open.ac.uk for further information.

Applications should include: