Microplastics (MPs) are an emerging group of environmental contaminants globally. One way they may enter croplands is via biosolids (sewage sludges), applied to soils to improve agricultural productivity. The effect of MPs on soil biology, soil structure and crop performance is poorly understood, which is of concern due to their environmental persistence. MPs can influence soil microbial activity and may affect earthworms and other soil biota which regulate soil structure. This can lead to problems with soil stability and drainage, impacting nutrient cycling and crop yield. However, it is unclear if current concentrations of MPs in biosolids adversely affect UK arable soils, and what application rates would present unacceptable risks. Research is urgently needed to determine the level of risk to arable soil from MPs at current rates of biosolids inputs, and better understand the impacts of MPs.
This PhD will investigate how MPs affect soil biota and crop performance in biosolid-amended arable soils. It will assess effects of biosolids, containing varying amounts of MPs, on soil organisms (including earthworms) involved in soil aggregation and drainage pore spaces, under different arable land management practices, and how these influence the mobility and fate of MPs within soil. MPs in biosolids will be characterised, and selected biosolids added in field trials to compare effects on soil and crops (wheat and short-term grass-clover pasture). The research will inform water industry management practice for biosolid application to soil.
This PhD will be undertaken within the EPSRC Centre for Doctoral Training in Water Infrastructure and Resilience (CDT WIRe). CDT WIRe is a collaboration between the three leading UK Universities in water resilient infrastructure. Students will benefit from a bespoke training scheme delivered by world leading experts from academia and industry, access to world leading experimental and computational facilities as well as close and regular contact with industry and end user partners. CDT WIRe is committed to promoting a diverse and inclusive community, and offer a range of family friendly, inclusive employment policies. For further information on the CDT WIRe scheme visit the web site: https://cdtwire.com/
The project will be supervised at the University of Sheffield by Prof Steven Thornton and Prof Jonathan Leake, in collaboration with Prof Mark Hodson (University of York), Dr Jesus Ojeda (Swansea University) and Dr Zoë Frogbrook (Scottish Water).
Normal EPSRC funding eligibility applies to this award, so students must have a relevant connection with the UK (usually established by residence).
At least a 2:1 honours degree in Microbiology, Environmental Science, and scientific disciplines where the candidate has specialised in environmental sciences (including Engineering, Chemistry, Biosciences). Experience in microbiological and environmental chemical analysis, and experimental work would be helpful.
How to apply
Interested candidates should email a covering letter and CV to Lindsay Hopcroft (l.hopcroft @sheffield.ac.uk).
For information and informal enquiries contact: Prof Steven Thornton ([email protected]