PhD in Future proofing sludge treatment centres for AMP7 and beyond

Cranfield University

Cranfield, UK 🇬🇧

This prestigious EPSRC Doctoral Training Partnership award, co-funded by the industrial partner, Severn Trent Water, provides a three-year fully-funded PhD studentship. The successful candidate will work within a multi-disciplinary team supported by both academic and industry supervisors on research that aims to evaluate the extent to which anaerobic digestion can be used to treat sludge mixtures with a high surplus activated sludge (SAS) to primary sludge (PS) ratio, whilst maintaining optimal treatment efficiency and stability; and to assess potential of entirely new treatment options that can future-proof sludge treatment centres.

The implementation of tighter treatment standards required from wastewater treatment plants has resulted in a change in the nature and volumes of sludge generated on site that require further dedicated treatment. Quality programmes planned for the next water infrastructure funding period (AMP7) for the wastewater industry, will result in a significant increase in the volume of activated sludge produced; as a result of new activated sludge processes (ASP) or chemical dosing schemes to meet tighter nutrient permits. This surplus activated sludge (SAS) is usually treated by anaerobic digestion (AD) at an empirical mixing ratio around 40:60% with primary sludge (PS) in order to generate renewable energy and an organic fertilizer (biosolids). Higher SAS to PS ratios can result in increased instability and process failures in sludge treatment processes. New insights that can sustain efficient and sustainable sludge management processes are needed and this project aims to evaluate the extent to which AD can be used to treat sludge mixtures with a high SAS to PS ratios, whilst maintaining optimal treatment efficiency and renewable energy formation in the form of biogas. The project will also assess the potential of entirely new treatment options that can future-proof sludge treatment centres while promoting circular economy principles.

This PhD project will address the following research objectives:

  1. Identifying research gaps for anaerobic digestion of wastewater sludge with high SAS to PS ratio, including potential causes for process failure, optimisation strategies and implication on foaming and biosolids dewaterability.
  2. Characterisation of PS and SAS from extensive sampling from full-scale sludge treatment centres, while capturing relevant process information influencing sludge properties.
  3. Experimentally evaluating the digestibility of sludge with varying SAS to PS ratios and identify factors influencing stability as well as propose and test optimisation strategies to improve the digestion efficiency.
  4. Investigate alternative treatment options to AD and implications of new associated value recovery routes and energy vectors for the sector.

Cranfield University is a unique learning environment with world-class programmes, unrivalled facilities and close links with business, industry and governments, all combining to attract the best students and teaching staff from around the world. In the last Research Excellence Framework (REF) assessment, 81% of research at Cranfield was rated as world-leading or internationally excellent.

Severn Trent Water (STW) is one of the largest regulated water and wastewater businesses in England and Wales providing services to more than 4.5 million households and businesses. They are a national leader in university / industry collaboration with a well-established, productive research relationship with Cranfield University.

This project delivers against the strategic needs in the area of bioresources of one of the UK’s major water utilities, with support from stakeholders from Severn Trent’s Innovation and Bioresources teams. The student will become a member of ST’s Bioresources community of practice, where he/she will be exposed to stakeholders from across the business and deliver regular updates on project findings. He/she will also learn about current sludge management and treatment practices by visiting sludge treatment centres and interacting with site practitioners.

The successful candidate will have the opportunity to work alongside the industry sponsor and gain significant experience in industrial research and development. It is expected that the candidate will attend and present at national and international conferences.

The candidate will receive significant level of technical training including design of experiments, a range of analytical skills, instrumentation and other transferable skills. The combination of academic and industry contacts will be beneficial to the candidate’s learning experience and future employability and career development. This project provides great exposure to the water industry sector.

At a glance

  • Application deadline26 Nov 2021
  • Award type(s)PhD
  • Start date31 Jan 2022
  • Duration of award3 years
  • EligibilityUK
  • Reference numberSWEE0159

Entry requirements

Applicants should have a first or second class UK honours degree or equivalent in a related discipline. This project would suit an applicant with a strong interest on environment engineering and development of sustainable treatment solutions, who is keen on industry-academic collaboration and on applied research. Applicants with a background on biology, chemistry, engineering, water science or environmental science will be particularly well suited for this project.


Sponsored by the EPSRC, Severn Trent Water and Cranfield University, this Doctoral Training Partnership studentship will provide a bursary of up to ÂŁ18,000 (tax-free) plus UK Home student fees for three years.

Our Values

Our shared, stated values help to define who we are and underpin everything we do: Ambition; Impact; Respect; and Community. Find out more here. We aim to create and maintain a culture in which everyone can work and study together and realise their full potential.

Diversity and Inclusion

Our equal opportunities and diversity monitoring has shown that women and minority ethnic groups are currently underrepresented within the university and so we actively encourage applications from eligible candidates from these groups.

Cranfield Doctoral Network

Research students at Cranfield benefit from being part of a dynamic, focused and professional study environment and all become valued members of the Cranfield Doctoral Network. This network brings together both research students and staff, providing a platform for our researchers to share ideas and collaborate in a multi-disciplinary environment. It aims to encourage an effective and vibrant research culture, founded upon the diversity of activities and knowledge. A tailored programme of seminars and events, alongside our Doctoral Researchers Core Development programme (transferable skills training), provide those studying a research degree with a wealth of social and networking opportunities.

How to apply

For further information please contact: 
Dr Yadira BajĂłn Fernández and Dr Ying Jiang
E: [email protected] and [email protected]
If you are eligible to apply for this studentship, please complete the online application form.

For further information contact us today:
T: +44 (0)1234 758082
E: [email protected]





IHE Delft Institute for Water Education - MSc in Water and Sustainable Development